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Diffstat (limited to 'systems/texlive/tlnet/tlpkg/tlperl/lib/Config.pod')
| -rw-r--r-- | systems/texlive/tlnet/tlpkg/tlperl/lib/Config.pod | 19577 |
1 files changed, 9811 insertions, 9766 deletions
diff --git a/systems/texlive/tlnet/tlpkg/tlperl/lib/Config.pod b/systems/texlive/tlnet/tlpkg/tlperl/lib/Config.pod index cbb4fcd8f6..629d2eca92 100644 --- a/systems/texlive/tlnet/tlpkg/tlperl/lib/Config.pod +++ b/systems/texlive/tlnet/tlpkg/tlperl/lib/Config.pod @@ -1,9766 +1,9811 @@ -=head1 NAME
-
-=for comment Generated by configpm. Any changes made here will be lost!
-
-Config - access Perl configuration information
-
-=head1 SYNOPSIS
-
- use Config;
- if ($Config{usethreads}) {
- print "has thread support\n"
- }
-
- use Config qw(myconfig config_sh config_vars config_re);
-
- print myconfig();
-
- print config_sh();
-
- print config_re();
-
- config_vars(qw(osname archname));
-
-
-=head1 DESCRIPTION
-
-The Config module contains all the information that was available to
-the C<Configure> program at Perl build time (over 900 values).
-
-Shell variables from the F<config.sh> file (written by Configure) are
-stored in the readonly-variable C<%Config>, indexed by their names.
-
-Values stored in config.sh as 'undef' are returned as undefined
-values. The perl C<exists> function can be used to check if a
-named variable exists.
-
-For a description of the variables, please have a look at the
-Glossary file, as written in the Porting folder, or use the url:
-https://github.com/Perl/perl5/blob/blead/Porting/Glossary
-
-=over 4
-
-=item myconfig()
-
-Returns a textual summary of the major perl configuration values.
-See also C<-V> in L<perlrun/Command Switches>.
-
-=item config_sh()
-
-Returns the entire perl configuration information in the form of the
-original config.sh shell variable assignment script.
-
-=item config_re($regex)
-
-Like config_sh() but returns, as a list, only the config entries who's
-names match the $regex.
-
-=item config_vars(@names)
-
-Prints to STDOUT the values of the named configuration variable. Each is
-printed on a separate line in the form:
-
- name='value';
-
-Names which are unknown are output as C<name='UNKNOWN';>.
-See also C<-V:name> in L<perlrun/Command Switches>.
-
-=item bincompat_options()
-
-Returns a list of C pre-processor options used when compiling this F<perl>
-binary, which affect its binary compatibility with extensions.
-C<bincompat_options()> and C<non_bincompat_options()> are shown together in
-the output of C<perl -V> as I<Compile-time options>.
-
-=item non_bincompat_options()
-
-Returns a list of C pre-processor options used when compiling this F<perl>
-binary, which do not affect binary compatibility with extensions.
-
-=item compile_date()
-
-Returns the compile date (as a string), equivalent to what is shown by
-C<perl -V>
-
-=item local_patches()
-
-Returns a list of the names of locally applied patches, equivalent to what
-is shown by C<perl -V>.
-
-=item header_files()
-
-Returns a list of the header files that should be used as dependencies for
-XS code, for this version of Perl on this platform.
-
-=back
-
-=head1 EXAMPLE
-
-Here's a more sophisticated example of using %Config:
-
- use Config;
- use strict;
-
- my %sig_num;
- my @sig_name;
- unless($Config{sig_name} && $Config{sig_num}) {
- die "No sigs?";
- } else {
- my @names = split ' ', $Config{sig_name};
- @sig_num{@names} = split ' ', $Config{sig_num};
- foreach (@names) {
- $sig_name[$sig_num{$_}] ||= $_;
- }
- }
-
- print "signal #17 = $sig_name[17]\n";
- if ($sig_num{ALRM}) {
- print "SIGALRM is $sig_num{ALRM}\n";
- }
-
-=head1 WARNING
-
-Because this information is not stored within the perl executable
-itself it is possible (but unlikely) that the information does not
-relate to the actual perl binary which is being used to access it.
-
-The Config module is installed into the architecture and version
-specific library directory ($Config{installarchlib}) and it checks the
-perl version number when loaded.
-
-The values stored in config.sh may be either single-quoted or
-double-quoted. Double-quoted strings are handy for those cases where you
-need to include escape sequences in the strings. To avoid runtime variable
-interpolation, any C<$> and C<@> characters are replaced by C<\$> and
-C<\@>, respectively. This isn't foolproof, of course, so don't embed C<\$>
-or C<\@> in double-quoted strings unless you're willing to deal with the
-consequences. (The slashes will end up escaped and the C<$> or C<@> will
-trigger variable interpolation)
-
-=head1 GLOSSARY
-
-Most C<Config> variables are determined by the C<Configure> script
-on platforms supported by it (which is most UNIX platforms). Some
-platforms have custom-made C<Config> variables, and may thus not have
-some of the variables described below, or may have extraneous variables
-specific to that particular port. See the port specific documentation
-in such cases.
-
-=cut
-
-=head2 _
-
-=over 4
-
-=item C<_a>
-
-From F<Unix.U>:
-
-This variable defines the extension used for ordinary library files.
-For unix, it is F<.a>. The F<.> is included. Other possible
-values include F<.lib>.
-
-=item C<_exe>
-
-From F<Unix.U>:
-
-This variable defines the extension used for executable files.
-C<DJGPP>, Cygwin and F<OS/2> use F<.exe>. Stratus C<VOS> uses F<.pm>.
-On operating systems which do not require a specific extension
-for executable files, this variable is empty.
-
-=item C<_o>
-
-From F<Unix.U>:
-
-This variable defines the extension used for object files.
-For unix, it is F<.o>. The F<.> is included. Other possible
-values include F<.obj>.
-
-=back
-
-=head2 a
-
-=over 4
-
-=item C<afs>
-
-From F<afs.U>:
-
-This variable is set to C<true> if C<AFS> (Andrew File System) is used
-on the system, C<false> otherwise. It is possible to override this
-with a hint value or command line option, but you'd better know
-what you are doing.
-
-=item C<afsroot>
-
-From F<afs.U>:
-
-This variable is by default set to F</afs>. In the unlikely case
-this is not the correct root, it is possible to override this with
-a hint value or command line option. This will be used in subsequent
-tests for AFSness in the configure and test process.
-
-=item C<alignbytes>
-
-From F<alignbytes.U>:
-
-This variable holds the number of bytes required to align a
-double-- or a long double when applicable. Usual values are
-2, 4 and 8. The default is eight, for safety.
-
-=item C<aphostname>
-
-From F<d_gethname.U>:
-
-This variable contains the command which can be used to compute the
-host name. The command is fully qualified by its absolute path, to make
-it safe when used by a process with super-user privileges.
-
-=item C<api_revision>
-
-From F<patchlevel.U>:
-
-The three variables, api_revision, api_version, and
-api_subversion, specify the version of the oldest perl binary
-compatible with the present perl. In a full version string
-such as F<5.6.1>, api_revision is the C<5>.
-Prior to 5.5.640, the format was a floating point number,
-like 5.00563.
-
-F<perl.c>:incpush() and F<lib/lib.pm> will automatically search in
-F<$sitelib/.>. for older directories back to the limit specified
-by these api_ variables. This is only useful if you have a
-perl library directory tree structured like the default one.
-See C<INSTALL> for how this works. The versioned site_perl
-directory was introduced in 5.005, so that is the lowest
-possible value. The version list appropriate for the current
-system is determined in F<inc_version_list.U>.
-
-C<XXX> To do: Since compatibility can depend on compile time
-options (such as bincompat, longlong, etc.) it should
-(perhaps) be set by Configure, but currently it isn't.
-Currently, we read a hard-wired value from F<patchlevel.h>.
-Perhaps what we ought to do is take the hard-wired value from
-F<patchlevel.h> but then modify it if the current Configure
-options warrant. F<patchlevel.h> then would use an #ifdef guard.
-
-=item C<api_subversion>
-
-From F<patchlevel.U>:
-
-The three variables, api_revision, api_version, and
-api_subversion, specify the version of the oldest perl binary
-compatible with the present perl. In a full version string
-such as F<5.6.1>, api_subversion is the C<1>. See api_revision for
-full details.
-
-=item C<api_version>
-
-From F<patchlevel.U>:
-
-The three variables, api_revision, api_version, and
-api_subversion, specify the version of the oldest perl binary
-compatible with the present perl. In a full version string
-such as F<5.6.1>, api_version is the C<6>. See api_revision for
-full details. As a special case, 5.5.0 is rendered in the
-old-style as 5.005. (In the 5.005_0x maintenance series,
-this was the only versioned directory in $sitelib.)
-
-=item C<api_versionstring>
-
-From F<patchlevel.U>:
-
-This variable combines api_revision, api_version, and
-api_subversion in a format such as 5.6.1 (or 5_6_1) suitable
-for use as a directory name. This is filesystem dependent.
-
-=item C<ar>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the ar program. After Configure runs,
-the value is reset to a plain C<ar> and is not useful.
-
-=item C<archlib>
-
-From F<archlib.U>:
-
-This variable holds the name of the directory in which the user wants
-to put architecture-dependent public library files for $package.
-It is most often a local directory such as F</usr/local/lib>.
-Programs using this variable must be prepared to deal
-with filename expansion.
-
-=item C<archlibexp>
-
-From F<archlib.U>:
-
-This variable is the same as the archlib variable, but is
-filename expanded at configuration time, for convenient use.
-
-=item C<archname>
-
-From F<archname.U>:
-
-This variable is a short name to characterize the current
-architecture. It is used mainly to construct the default archlib.
-
-=item C<archname64>
-
-From F<use64bits.U>:
-
-This variable is used for the 64-bitness part of $archname.
-
-=item C<archobjs>
-
-From F<Unix.U>:
-
-This variable defines any additional objects that must be linked
-in with the program on this architecture. On unix, it is usually
-empty. It is typically used to include emulations of unix calls
-or other facilities. For perl on F<OS/2>, for example, this would
-include F<os2/os2.obj>.
-
-=item C<asctime_r_proto>
-
-From F<d_asctime_r.U>:
-
-This variable encodes the prototype of asctime_r.
-It is zero if d_asctime_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_asctime_r
-is defined.
-
-=item C<awk>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the awk program. After Configure runs,
-the value is reset to a plain C<awk> and is not useful.
-
-=back
-
-=head2 b
-
-=over 4
-
-=item C<baserev>
-
-From F<baserev.U>:
-
-The base revision level of this package, from the F<.package> file.
-
-=item C<bash>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<bin>
-
-From F<bin.U>:
-
-This variable holds the name of the directory in which the user wants
-to put publicly executable images for the package in question. It
-is most often a local directory such as F</usr/local/bin>. Programs using
-this variable must be prepared to deal with F<~name> substitution.
-
-=item C<bin_ELF>
-
-From F<dlsrc.U>:
-
-This variable saves the result from configure if generated binaries
-are in C<ELF> format. Only set to defined when the test has actually
-been performed, and the result was positive.
-
-=item C<binexp>
-
-From F<bin.U>:
-
-This is the same as the bin variable, but is filename expanded at
-configuration time, for use in your makefiles.
-
-=item C<bison>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the bison program. After Configure runs,
-the value is reset to a plain C<bison> and is not useful.
-
-=item C<byacc>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the byacc program. After Configure runs,
-the value is reset to a plain C<byacc> and is not useful.
-
-=item C<byteorder>
-
-From F<byteorder.U>:
-
-This variable holds the byte order in a C<UV>. In the following,
-larger digits indicate more significance. The variable byteorder
-is either 4321 on a big-endian machine, or 1234 on a little-endian,
-or 87654321 on a Cray ... or 3412 with weird order !
-
-=back
-
-=head2 c
-
-=over 4
-
-=item C<c>
-
-From F<n.U>:
-
-This variable contains the \c string if that is what causes the echo
-command to suppress newline. Otherwise it is null. Correct usage is
-$echo $n "prompt for a question: $c".
-
-=item C<castflags>
-
-From F<d_castneg.U>:
-
-This variable contains a flag that precise difficulties the
-compiler has casting odd floating values to unsigned long:
-0 = ok
-1 = couldn't cast < 0
-2 = couldn't cast >= 0x80000000
-4 = couldn't cast in argument expression list
-
-=item C<cat>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the cat program. After Configure runs,
-the value is reset to a plain C<cat> and is not useful.
-
-=item C<cc>
-
-From F<cc.U>:
-
-This variable holds the name of a command to execute a C compiler which
-can resolve multiple global references that happen to have the same
-name. Usual values are C<cc> and C<gcc>.
-Fervent C<ANSI> compilers may be called C<c89>. C<AIX> has xlc.
-
-=item C<cccdlflags>
-
-From F<dlsrc.U>:
-
-This variable contains any special flags that might need to be
-passed with C<cc -c> to compile modules to be used to create a shared
-library that will be used for dynamic loading. For hpux, this
-should be +z. It is up to the makefile to use it.
-
-=item C<ccdlflags>
-
-From F<dlsrc.U>:
-
-This variable contains any special flags that might need to be
-passed to cc to link with a shared library for dynamic loading.
-It is up to the makefile to use it. For sunos 4.1, it should
-be empty.
-
-=item C<ccflags>
-
-From F<ccflags.U>:
-
-This variable contains any additional C compiler flags desired by
-the user. It is up to the Makefile to use this.
-
-=item C<ccflags_uselargefiles>
-
-From F<uselfs.U>:
-
-This variable contains the compiler flags needed by large file builds
-and added to ccflags by hints files.
-
-=item C<ccname>
-
-From F<Checkcc.U>:
-
-This can set either by hints files or by Configure. If using
-gcc, this is gcc, and if not, usually equal to cc, unimpressive, no?
-Some platforms, however, make good use of this by storing the
-flavor of the C compiler being used here. For example if using
-the Sun WorkShop suite, ccname will be C<workshop>.
-
-=item C<ccsymbols>
-
-From F<Cppsym.U>:
-
-The variable contains the symbols defined by the C compiler alone.
-The symbols defined by cpp or by cc when it calls cpp are not in
-this list, see cppsymbols and cppccsymbols.
-The list is a space-separated list of symbol=value tokens.
-
-=item C<ccversion>
-
-From F<Checkcc.U>:
-
-This can set either by hints files or by Configure. If using
-a (non-gcc) vendor cc, this variable may contain a version for
-the compiler.
-
-=item C<cf_by>
-
-From F<cf_who.U>:
-
-Login name of the person who ran the Configure script and answered the
-questions. This is used to tag both F<config.sh> and F<config_h.SH>.
-
-=item C<cf_email>
-
-From F<cf_email.U>:
-
-Electronic mail address of the person who ran Configure. This can be
-used by units that require the user's e-mail, like F<MailList.U>.
-
-=item C<cf_time>
-
-From F<cf_who.U>:
-
-Holds the output of the C<date> command when the configuration file was
-produced. This is used to tag both F<config.sh> and F<config_h.SH>.
-
-=item C<charbits>
-
-From F<charsize.U>:
-
-This variable contains the value of the C<CHARBITS> symbol, which
-indicates to the C program how many bits there are in a character.
-
-=item C<charsize>
-
-From F<charsize.U>:
-
-This variable contains the value of the C<CHARSIZE> symbol, which
-indicates to the C program how many bytes there are in a character.
-
-=item C<chgrp>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<chmod>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the chmod program. After Configure runs,
-the value is reset to a plain C<chmod> and is not useful.
-
-=item C<chown>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<clocktype>
-
-From F<d_times.U>:
-
-This variable holds the type returned by times(). It can be long,
-or clock_t on C<BSD> sites (in which case <sys/types.h> should be
-included).
-
-=item C<comm>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the comm program. After Configure runs,
-the value is reset to a plain C<comm> and is not useful.
-
-=item C<compress>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<config_arg0>
-
-From F<Options.U>:
-
-This variable contains the string used to invoke the Configure
-command, as reported by the shell in the $0 variable.
-
-=item C<config_argc>
-
-From F<Options.U>:
-
-This variable contains the number of command-line arguments
-passed to Configure, as reported by the shell in the $# variable.
-The individual arguments are stored as variables config_arg1,
-config_arg2, etc.
-
-=item C<config_args>
-
-From F<Options.U>:
-
-This variable contains a single string giving the command-line
-arguments passed to Configure. Spaces within arguments,
-quotes, and escaped characters are not correctly preserved.
-To reconstruct the command line, you must assemble the individual
-command line pieces, given in config_arg[0-9]*.
-
-=item C<contains>
-
-From F<contains.U>:
-
-This variable holds the command to do a grep with a proper return
-status. On most sane systems it is simply C<grep>. On insane systems
-it is a grep followed by a cat followed by a test. This variable
-is primarily for the use of other Configure units.
-
-=item C<cp>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the cp program. After Configure runs,
-the value is reset to a plain C<cp> and is not useful.
-
-=item C<cpio>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<cpp>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the cpp program. After Configure runs,
-the value is reset to a plain C<cpp> and is not useful.
-
-=item C<cpp_stuff>
-
-From F<cpp_stuff.U>:
-
-This variable contains an identification of the concatenation mechanism
-used by the C preprocessor.
-
-=item C<cppccsymbols>
-
-From F<Cppsym.U>:
-
-The variable contains the symbols defined by the C compiler
-when it calls cpp. The symbols defined by the cc alone or cpp
-alone are not in this list, see ccsymbols and cppsymbols.
-The list is a space-separated list of symbol=value tokens.
-
-=item C<cppflags>
-
-From F<ccflags.U>:
-
-This variable holds the flags that will be passed to the C pre-
-processor. It is up to the Makefile to use it.
-
-=item C<cpplast>
-
-From F<cppstdin.U>:
-
-This variable has the same functionality as cppminus, only it applies
-to cpprun and not cppstdin.
-
-=item C<cppminus>
-
-From F<cppstdin.U>:
-
-This variable contains the second part of the string which will invoke
-the C preprocessor on the standard input and produce to standard
-output. This variable will have the value C<-> if cppstdin needs
-a minus to specify standard input, otherwise the value is "".
-
-=item C<cpprun>
-
-From F<cppstdin.U>:
-
-This variable contains the command which will invoke a C preprocessor
-on standard input and put the output to stdout. It is guaranteed not
-to be a wrapper and may be a null string if no preprocessor can be
-made directly available. This preprocessor might be different from the
-one used by the C compiler. Don't forget to append cpplast after the
-preprocessor options.
-
-=item C<cppstdin>
-
-From F<cppstdin.U>:
-
-This variable contains the command which will invoke the C
-preprocessor on standard input and put the output to stdout.
-It is primarily used by other Configure units that ask about
-preprocessor symbols.
-
-=item C<cppsymbols>
-
-From F<Cppsym.U>:
-
-The variable contains the symbols defined by the C preprocessor
-alone. The symbols defined by cc or by cc when it calls cpp are
-not in this list, see ccsymbols and cppccsymbols.
-The list is a space-separated list of symbol=value tokens.
-
-=item C<crypt_r_proto>
-
-From F<d_crypt_r.U>:
-
-This variable encodes the prototype of crypt_r.
-It is zero if d_crypt_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_crypt_r
-is defined.
-
-=item C<cryptlib>
-
-From F<d_crypt.U>:
-
-This variable holds -lcrypt or the path to a F<libcrypt.a> archive if
-the crypt() function is not defined in the standard C library. It is
-up to the Makefile to use this.
-
-=item C<csh>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the csh program. After Configure runs,
-the value is reset to a plain C<csh> and is not useful.
-
-=item C<ctermid_r_proto>
-
-From F<d_ctermid_r.U>:
-
-This variable encodes the prototype of ctermid_r.
-It is zero if d_ctermid_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_ctermid_r
-is defined.
-
-=item C<ctime_r_proto>
-
-From F<d_ctime_r.U>:
-
-This variable encodes the prototype of ctime_r.
-It is zero if d_ctime_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_ctime_r
-is defined.
-
-=back
-
-=head2 d
-
-=over 4
-
-=item C<d__fwalk>
-
-From F<d__fwalk.U>:
-
-This variable conditionally defines C<HAS__FWALK> if _fwalk() is
-available to apply a function to all the file handles.
-
-=item C<d_accept4>
-
-From F<d_accept4.U>:
-
-This variable conditionally defines HAS_ACCEPT4 if accept4() is
-available to accept socket connections.
-
-=item C<d_access>
-
-From F<d_access.U>:
-
-This variable conditionally defines C<HAS_ACCESS> if the access() system
-call is available to check for access permissions using real IDs.
-
-=item C<d_accessx>
-
-From F<d_accessx.U>:
-
-This variable conditionally defines the C<HAS_ACCESSX> symbol, which
-indicates to the C program that the accessx() routine is available.
-
-=item C<d_acosh>
-
-From F<d_acosh.U>:
-
-This variable conditionally defines the C<HAS_ACOSH> symbol, which
-indicates to the C program that the acosh() routine is available.
-
-=item C<d_aintl>
-
-From F<d_aintl.U>:
-
-This variable conditionally defines the C<HAS_AINTL> symbol, which
-indicates to the C program that the aintl() routine is available.
-If copysignl is also present we can emulate modfl.
-
-=item C<d_alarm>
-
-From F<d_alarm.U>:
-
-This variable conditionally defines the C<HAS_ALARM> symbol, which
-indicates to the C program that the alarm() routine is available.
-
-=item C<d_archlib>
-
-From F<archlib.U>:
-
-This variable conditionally defines C<ARCHLIB> to hold the pathname
-of architecture-dependent library files for $package. If
-$archlib is the same as $privlib, then this is set to undef.
-
-=item C<d_asctime64>
-
-From F<d_timefuncs64.U>:
-
-This variable conditionally defines the HAS_ASCTIME64 symbol, which
-indicates to the C program that the asctime64 () routine is available.
-
-=item C<d_asctime_r>
-
-From F<d_asctime_r.U>:
-
-This variable conditionally defines the C<HAS_ASCTIME_R> symbol,
-which indicates to the C program that the asctime_r()
-routine is available.
-
-=item C<d_asinh>
-
-From F<d_asinh.U>:
-
-This variable conditionally defines the C<HAS_ASINH> symbol, which
-indicates to the C program that the asinh() routine is available.
-
-=item C<d_atanh>
-
-From F<d_atanh.U>:
-
-This variable conditionally defines the C<HAS_ATANH> symbol, which
-indicates to the C program that the atanh() routine is available.
-
-=item C<d_atolf>
-
-From F<atolf.U>:
-
-This variable conditionally defines the C<HAS_ATOLF> symbol, which
-indicates to the C program that the atolf() routine is available.
-
-=item C<d_atoll>
-
-From F<atoll.U>:
-
-This variable conditionally defines the C<HAS_ATOLL> symbol, which
-indicates to the C program that the atoll() routine is available.
-
-=item C<d_attribute_deprecated>
-
-From F<d_attribut.U>:
-
-This variable conditionally defines C<HASATTRIBUTE_DEPRECATED>, which
-indicates that C<GCC> can handle the attribute for marking deprecated
-APIs
-
-=item C<d_attribute_format>
-
-From F<d_attribut.U>:
-
-This variable conditionally defines C<HASATTRIBUTE_FORMAT>, which
-indicates the C compiler can check for printf-like formats.
-
-=item C<d_attribute_malloc>
-
-From F<d_attribut.U>:
-
-This variable conditionally defines C<HASATTRIBUTE_MALLOC>, which
-indicates the C compiler can understand functions as having
-malloc-like semantics.
-
-=item C<d_attribute_nonnull>
-
-From F<d_attribut.U>:
-
-This variable conditionally defines C<HASATTRIBUTE_NONNULL>, which
-indicates that the C compiler can know that certain arguments
-must not be C<NULL>, and will check accordingly at compile time.
-
-=item C<d_attribute_noreturn>
-
-From F<d_attribut.U>:
-
-This variable conditionally defines C<HASATTRIBUTE_NORETURN>, which
-indicates that the C compiler can know that certain functions
-are guaranteed never to return.
-
-=item C<d_attribute_pure>
-
-From F<d_attribut.U>:
-
-This variable conditionally defines C<HASATTRIBUTE_PURE>, which
-indicates that the C compiler can know that certain functions
-are C<pure> functions, meaning that they have no side effects, and
-only rely on function input F<and/or> global data for their results.
-
-=item C<d_attribute_unused>
-
-From F<d_attribut.U>:
-
-This variable conditionally defines C<HASATTRIBUTE_UNUSED>, which
-indicates that the C compiler can know that certain variables
-and arguments may not always be used, and to not throw warnings
-if they don't get used.
-
-=item C<d_attribute_warn_unused_result>
-
-From F<d_attribut.U>:
-
-This variable conditionally defines
-C<HASATTRIBUTE_WARN_UNUSED_RESULT>, which indicates that the C
-compiler can know that certain functions have a return values
-that must not be ignored, such as malloc() or open().
-
-=item C<d_backtrace>
-
-From F<d_backtrace.U>:
-
-This variable conditionally defines the C<HAS_BACKTRACE> symbol, which
-indicates to the C program that the backtrace() routine is available
-to get a stack trace.
-
-=item C<d_bsd>
-
-From F<Guess.U>:
-
-This symbol conditionally defines the symbol C<BSD> when running on a
-C<BSD> system.
-
-=item C<d_bsdgetpgrp>
-
-From F<d_getpgrp.U>:
-
-This variable conditionally defines C<USE_BSD_GETPGRP> if
-getpgrp needs one arguments whereas C<USG> one needs none.
-
-=item C<d_bsdsetpgrp>
-
-From F<d_setpgrp.U>:
-
-This variable conditionally defines C<USE_BSD_SETPGRP> if
-setpgrp needs two arguments whereas C<USG> one needs none.
-See also d_setpgid for a C<POSIX> interface.
-
-=item C<d_builtin_add_overflow>
-
-From F<d_builtin_overflow.U>:
-
-This variable conditionally defines C<HAS_BUILTIN_ADD_OVERFLOW>, which
-indicates that the compiler supports __builtin_add_overflow(x,y,&z)
-for safely adding x and y into z while checking for overflow.
-
-=item C<d_builtin_choose_expr>
-
-From F<d_builtin.U>:
-
-This conditionally defines C<HAS_BUILTIN_CHOOSE_EXPR>, which
-indicates that the compiler supports __builtin_choose_expr(x,y,z).
-This built-in function is analogous to the C<x?y:z> operator in C,
-except that the expression returned has its type unaltered by
-promotion rules. Also, the built-in function does not evaluate
-the expression that was not chosen.
-
-=item C<d_builtin_expect>
-
-From F<d_builtin.U>:
-
-This conditionally defines C<HAS_BUILTIN_EXPECT>, which indicates
-that the compiler supports __builtin_expect(exp,c). You may use
-__builtin_expect to provide the compiler with branch prediction
-information.
-
-=item C<d_builtin_mul_overflow>
-
-From F<d_builtin_overflow.U>:
-
-This variable conditionally defines C<HAS_BUILTIN_MUL_OVERFLOW>, which
-indicates that the compiler supports __builtin_mul_overflow(x,y,&z)
-for safely multiplying x and y into z while checking for overflow.
-
-=item C<d_builtin_sub_overflow>
-
-From F<d_builtin_overflow.U>:
-
-This variable conditionally defines C<HAS_BUILTIN_SUB_OVERFLOW>, which
-indicates that the compiler supports __builtin_sub_overflow(x,y,&z)
-for safely subtracting y from x into z while checking for overflow.
-
-=item C<d_c99_variadic_macros>
-
-From F<d_c99_variadic.U>:
-
-This variable conditionally defines the HAS_C99_VARIADIC_MACROS
-symbol, which indicates to the C program that C99 variadic macros
-are available.
-
-=item C<d_casti32>
-
-From F<d_casti32.U>:
-
-This variable conditionally defines CASTI32, which indicates
-whether the C compiler can cast large floats to 32-bit ints.
-
-=item C<d_castneg>
-
-From F<d_castneg.U>:
-
-This variable conditionally defines C<CASTNEG>, which indicates
-whether the C compiler can cast negative float to unsigned.
-
-=item C<d_cbrt>
-
-From F<d_cbrt.U>:
-
-This variable conditionally defines the C<HAS_CBRT> symbol, which
-indicates to the C program that the cbrt() (cube root) function
-is available.
-
-=item C<d_chown>
-
-From F<d_chown.U>:
-
-This variable conditionally defines the C<HAS_CHOWN> symbol, which
-indicates to the C program that the chown() routine is available.
-
-=item C<d_chroot>
-
-From F<d_chroot.U>:
-
-This variable conditionally defines the C<HAS_CHROOT> symbol, which
-indicates to the C program that the chroot() routine is available.
-
-=item C<d_chsize>
-
-From F<d_chsize.U>:
-
-This variable conditionally defines the C<CHSIZE> symbol, which
-indicates to the C program that the chsize() routine is available
-to truncate files. You might need a -lx to get this routine.
-
-=item C<d_class>
-
-From F<d_class.U>:
-
-This variable conditionally defines the C<HAS_CLASS> symbol, which
-indicates to the C program that the class() routine is available.
-
-=item C<d_clearenv>
-
-From F<d_clearenv.U>:
-
-This variable conditionally defines the C<HAS_CLEARENV> symbol, which
-indicates to the C program that the clearenv () routine is available.
-
-=item C<d_closedir>
-
-From F<d_closedir.U>:
-
-This variable conditionally defines C<HAS_CLOSEDIR> if closedir() is
-available.
-
-=item C<d_cmsghdr_s>
-
-From F<d_cmsghdr_s.U>:
-
-This variable conditionally defines the C<HAS_STRUCT_CMSGHDR> symbol,
-which indicates that the struct cmsghdr is supported.
-
-=item C<d_copysign>
-
-From F<d_copysign.U>:
-
-This variable conditionally defines the C<HAS_COPYSIGN> symbol, which
-indicates to the C program that the copysign() routine is available.
-
-=item C<d_copysignl>
-
-From F<d_copysignl.U>:
-
-This variable conditionally defines the C<HAS_COPYSIGNL> symbol, which
-indicates to the C program that the copysignl() routine is available.
-If aintl is also present we can emulate modfl.
-
-=item C<d_cplusplus>
-
-From F<d_cplusplus.U>:
-
-This variable conditionally defines the C<USE_CPLUSPLUS> symbol, which
-indicates that a C++ compiler was used to compiled Perl and will be
-used to compile extensions.
-
-=item C<d_crypt>
-
-From F<d_crypt.U>:
-
-This variable conditionally defines the C<CRYPT> symbol, which
-indicates to the C program that the crypt() routine is available
-to encrypt passwords and the like.
-
-=item C<d_crypt_r>
-
-From F<d_crypt_r.U>:
-
-This variable conditionally defines the C<HAS_CRYPT_R> symbol,
-which indicates to the C program that the crypt_r()
-routine is available.
-
-=item C<d_csh>
-
-From F<d_csh.U>:
-
-This variable conditionally defines the C<CSH> symbol, which
-indicates to the C program that the C-shell exists.
-
-=item C<d_ctermid>
-
-From F<d_ctermid.U>:
-
-This variable conditionally defines C<CTERMID> if ctermid() is
-available to generate filename for terminal.
-
-=item C<d_ctermid_r>
-
-From F<d_ctermid_r.U>:
-
-This variable conditionally defines the C<HAS_CTERMID_R> symbol,
-which indicates to the C program that the ctermid_r()
-routine is available.
-
-=item C<d_ctime64>
-
-From F<d_timefuncs64.U>:
-
-This variable conditionally defines the HAS_CTIME64 symbol, which
-indicates to the C program that the ctime64 () routine is available.
-
-=item C<d_ctime_r>
-
-From F<d_ctime_r.U>:
-
-This variable conditionally defines the C<HAS_CTIME_R> symbol,
-which indicates to the C program that the ctime_r()
-routine is available.
-
-=item C<d_cuserid>
-
-From F<d_cuserid.U>:
-
-This variable conditionally defines the C<HAS_CUSERID> symbol, which
-indicates to the C program that the cuserid() routine is available
-to get character login names.
-
-=item C<d_dbminitproto>
-
-From F<d_dbminitproto.U>:
-
-This variable conditionally defines the C<HAS_DBMINIT_PROTO> symbol,
-which indicates to the C program that the system provides
-a prototype for the dbminit() function. Otherwise, it is
-up to the program to supply one.
-
-=item C<d_difftime>
-
-From F<d_difftime.U>:
-
-This variable conditionally defines the C<HAS_DIFFTIME> symbol, which
-indicates to the C program that the difftime() routine is available.
-
-=item C<d_difftime64>
-
-From F<d_timefuncs64.U>:
-
-This variable conditionally defines the HAS_DIFFTIME64 symbol, which
-indicates to the C program that the difftime64 () routine is available.
-
-=item C<d_dir_dd_fd>
-
-From F<d_dir_dd_fd.U>:
-
-This variable conditionally defines the C<HAS_DIR_DD_FD> symbol, which
-indicates that the C<DIR> directory stream type contains a member
-variable called dd_fd.
-
-=item C<d_dirfd>
-
-From F<d_dirfd.U>:
-
-This variable conditionally defines the C<HAS_DIRFD> constant,
-which indicates to the C program that dirfd() is available
-to return the file descriptor of a directory stream.
-
-=item C<d_dirnamlen>
-
-From F<i_dirent.U>:
-
-This variable conditionally defines C<DIRNAMLEN>, which indicates
-to the C program that the length of directory entry names is
-provided by a d_namelen field.
-
-=item C<d_dladdr>
-
-From F<d_dladdr.U>:
-
-This variable conditionally defines the C<HAS_DLADDR> symbol, which
-indicates to the C program that the dladdr() routine is available
-to get a stack trace.
-
-=item C<d_dlerror>
-
-From F<d_dlerror.U>:
-
-This variable conditionally defines the C<HAS_DLERROR> symbol, which
-indicates to the C program that the dlerror() routine is available.
-
-=item C<d_dlopen>
-
-From F<d_dlopen.U>:
-
-This variable conditionally defines the C<HAS_DLOPEN> symbol, which
-indicates to the C program that the dlopen() routine is available.
-
-=item C<d_dlsymun>
-
-From F<d_dlsymun.U>:
-
-This variable conditionally defines C<DLSYM_NEEDS_UNDERSCORE>, which
-indicates that we need to prepend an underscore to the symbol
-name before calling dlsym().
-
-=item C<d_dosuid>
-
-From F<d_dosuid.U>:
-
-This variable conditionally defines the symbol C<DOSUID>, which
-tells the C program that it should insert setuid emulation code
-on hosts which have setuid #! scripts disabled.
-
-=item C<d_double_has_inf>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the symbol C<DOUBLE_HAS_INF>
-which indicates that the double type has an infinity.
-
-=item C<d_double_has_nan>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the symbol C<DOUBLE_HAS_NAN>
-which indicates that the double type has a not-a-number.
-
-=item C<d_double_has_negative_zero>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the symbol C<DOUBLE_HAS_NEGATIVE_ZERO>
-which indicates that the double type has a negative zero.
-
-=item C<d_double_has_subnormals>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the symbol C<DOUBLE_HAS_SUBNORMALS>
-which indicates that the double type has subnormals (denormals).
-
-=item C<d_double_style_cray>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the symbol C<DOUBLE_STYLE_CRAY>
-which indicates that the double is the 64-bit C<CRAY> mainframe format.
-
-=item C<d_double_style_ibm>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the symbol C<DOUBLE_STYLE_IBM>,
-which indicates that the double is the 64-bit C<IBM> mainframe format.
-
-=item C<d_double_style_ieee>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the symbol C<DOUBLE_STYLE_IEEE>,
-which indicates that the double is the 64-bit C<IEEE> 754.
-
-=item C<d_double_style_vax>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the symbol C<DOUBLE_STYLE_VAX>,
-which indicates that the double is the 64-bit C<VAX> format D or G.
-
-=item C<d_drand48_r>
-
-From F<d_drand48_r.U>:
-
-This variable conditionally defines the HAS_DRAND48_R symbol,
-which indicates to the C program that the drand48_r()
-routine is available.
-
-=item C<d_drand48proto>
-
-From F<d_drand48proto.U>:
-
-This variable conditionally defines the HAS_DRAND48_PROTO symbol,
-which indicates to the C program that the system provides
-a prototype for the drand48() function. Otherwise, it is
-up to the program to supply one.
-
-=item C<d_dup2>
-
-From F<d_dup2.U>:
-
-This variable conditionally defines HAS_DUP2 if dup2() is
-available to duplicate file descriptors.
-
-=item C<d_dup3>
-
-From F<d_dup3.U>:
-
-This variable conditionally defines HAS_DUP3 if dup3() is
-available to duplicate file descriptors.
-
-=item C<d_duplocale>
-
-From F<d_newlocale.U>:
-
-This variable conditionally defines the C<HAS_DUPLOCALE> symbol, which
-indicates to the C program that the duplocale() routine is available
-to duplicate a locale object.
-
-=item C<d_eaccess>
-
-From F<d_eaccess.U>:
-
-This variable conditionally defines the C<HAS_EACCESS> symbol, which
-indicates to the C program that the eaccess() routine is available.
-
-=item C<d_endgrent>
-
-From F<d_endgrent.U>:
-
-This variable conditionally defines the C<HAS_ENDGRENT> symbol, which
-indicates to the C program that the endgrent() routine is available
-for sequential access of the group database.
-
-=item C<d_endgrent_r>
-
-From F<d_endgrent_r.U>:
-
-This variable conditionally defines the C<HAS_ENDGRENT_R> symbol,
-which indicates to the C program that the endgrent_r()
-routine is available.
-
-=item C<d_endhent>
-
-From F<d_endhent.U>:
-
-This variable conditionally defines C<HAS_ENDHOSTENT> if endhostent() is
-available to close whatever was being used for host queries.
-
-=item C<d_endhostent_r>
-
-From F<d_endhostent_r.U>:
-
-This variable conditionally defines the C<HAS_ENDHOSTENT_R> symbol,
-which indicates to the C program that the endhostent_r()
-routine is available.
-
-=item C<d_endnent>
-
-From F<d_endnent.U>:
-
-This variable conditionally defines C<HAS_ENDNETENT> if endnetent() is
-available to close whatever was being used for network queries.
-
-=item C<d_endnetent_r>
-
-From F<d_endnetent_r.U>:
-
-This variable conditionally defines the C<HAS_ENDNETENT_R> symbol,
-which indicates to the C program that the endnetent_r()
-routine is available.
-
-=item C<d_endpent>
-
-From F<d_endpent.U>:
-
-This variable conditionally defines C<HAS_ENDPROTOENT> if endprotoent() is
-available to close whatever was being used for protocol queries.
-
-=item C<d_endprotoent_r>
-
-From F<d_endprotoent_r.U>:
-
-This variable conditionally defines the C<HAS_ENDPROTOENT_R> symbol,
-which indicates to the C program that the endprotoent_r()
-routine is available.
-
-=item C<d_endpwent>
-
-From F<d_endpwent.U>:
-
-This variable conditionally defines the C<HAS_ENDPWENT> symbol, which
-indicates to the C program that the endpwent() routine is available
-for sequential access of the passwd database.
-
-=item C<d_endpwent_r>
-
-From F<d_endpwent_r.U>:
-
-This variable conditionally defines the C<HAS_ENDPWENT_R> symbol,
-which indicates to the C program that the endpwent_r()
-routine is available.
-
-=item C<d_endsent>
-
-From F<d_endsent.U>:
-
-This variable conditionally defines C<HAS_ENDSERVENT> if endservent() is
-available to close whatever was being used for service queries.
-
-=item C<d_endservent_r>
-
-From F<d_endservent_r.U>:
-
-This variable conditionally defines the C<HAS_ENDSERVENT_R> symbol,
-which indicates to the C program that the endservent_r()
-routine is available.
-
-=item C<d_eofnblk>
-
-From F<nblock_io.U>:
-
-This variable conditionally defines C<EOF_NONBLOCK> if C<EOF> can be seen
-when reading from a non-blocking I/O source.
-
-=item C<d_erf>
-
-From F<d_erf.U>:
-
-This variable conditionally defines the C<HAS_ERF> symbol, which
-indicates to the C program that the erf() routine is available.
-
-=item C<d_erfc>
-
-From F<d_erfc.U>:
-
-This variable conditionally defines the C<HAS_ERFC> symbol, which
-indicates to the C program that the erfc() routine is available.
-
-=item C<d_eunice>
-
-From F<Guess.U>:
-
-This variable conditionally defines the symbols C<EUNICE> and C<VAX>, which
-alerts the C program that it must deal with idiosyncrasies of C<VMS>.
-
-=item C<d_exp2>
-
-From F<d_exp2.U>:
-
-This variable conditionally defines the HAS_EXP2 symbol, which
-indicates to the C program that the exp2() routine is available.
-
-=item C<d_expm1>
-
-From F<d_expm1.U>:
-
-This variable conditionally defines the HAS_EXPM1 symbol, which
-indicates to the C program that the expm1() routine is available.
-
-=item C<d_faststdio>
-
-From F<d_faststdio.U>:
-
-This variable conditionally defines the C<HAS_FAST_STDIO> symbol,
-which indicates to the C program that the "fast stdio" is available
-to manipulate the stdio buffers directly.
-
-=item C<d_fchdir>
-
-From F<d_fchdir.U>:
-
-This variable conditionally defines the C<HAS_FCHDIR> symbol, which
-indicates to the C program that the fchdir() routine is available.
-
-=item C<d_fchmod>
-
-From F<d_fchmod.U>:
-
-This variable conditionally defines the C<HAS_FCHMOD> symbol, which
-indicates to the C program that the fchmod() routine is available
-to change mode of opened files.
-
-=item C<d_fchmodat>
-
-From F<d_fsat.U>:
-
-This variable conditionally defines the C<HAS_FCHMODAT> symbol, which
-indicates the C<POSIX> fchmodat() function is available.
-
-=item C<d_fchown>
-
-From F<d_fchown.U>:
-
-This variable conditionally defines the C<HAS_FCHOWN> symbol, which
-indicates to the C program that the fchown() routine is available
-to change ownership of opened files.
-
-=item C<d_fcntl>
-
-From F<d_fcntl.U>:
-
-This variable conditionally defines the C<HAS_FCNTL> symbol, and indicates
-whether the fcntl() function exists
-
-=item C<d_fcntl_can_lock>
-
-From F<d_fcntl_can_lock.U>:
-
-This variable conditionally defines the C<FCNTL_CAN_LOCK> symbol
-and indicates whether file locking with fcntl() works.
-
-=item C<d_fd_macros>
-
-From F<d_fd_set.U>:
-
-This variable contains the eventual value of the C<HAS_FD_MACROS> symbol,
-which indicates if your C compiler knows about the macros which
-manipulate an fd_set.
-
-=item C<d_fd_set>
-
-From F<d_fd_set.U>:
-
-This variable contains the eventual value of the C<HAS_FD_SET> symbol,
-which indicates if your C compiler knows about the fd_set typedef.
-
-=item C<d_fdclose>
-
-From F<d_fdclose.U>:
-
-This variable conditionally defines the C<HAS_FDCLOSE> symbol, which
-indicates to the C program that the fdclose() routine is available.
-
-=item C<d_fdim>
-
-From F<d_fdim.U>:
-
-This variable conditionally defines the C<HAS_FDIM> symbol, which
-indicates to the C program that the fdim() routine is available.
-
-=item C<d_fds_bits>
-
-From F<d_fd_set.U>:
-
-This variable contains the eventual value of the C<HAS_FDS_BITS> symbol,
-which indicates if your fd_set typedef contains the fds_bits member.
-If you have an fd_set typedef, but the dweebs who installed it did
-a half-fast job and neglected to provide the macros to manipulate
-an fd_set, C<HAS_FDS_BITS> will let us know how to fix the gaffe.
-
-=item C<d_fegetround>
-
-From F<d_fegetround.U>:
-
-This variable conditionally defines C<HAS_FEGETROUND> if fegetround() is
-available to get the floating point rounding mode.
-
-=item C<d_fgetpos>
-
-From F<d_fgetpos.U>:
-
-This variable conditionally defines C<HAS_FGETPOS> if fgetpos() is
-available to get the file position indicator.
-
-=item C<d_finite>
-
-From F<d_finite.U>:
-
-This variable conditionally defines the C<HAS_FINITE> symbol, which
-indicates to the C program that the finite() routine is available.
-
-=item C<d_finitel>
-
-From F<d_finitel.U>:
-
-This variable conditionally defines the C<HAS_FINITEL> symbol, which
-indicates to the C program that the finitel() routine is available.
-
-=item C<d_flexfnam>
-
-From F<d_flexfnam.U>:
-
-This variable conditionally defines the C<FLEXFILENAMES> symbol, which
-indicates that the system supports filenames longer than 14 characters.
-
-=item C<d_flock>
-
-From F<d_flock.U>:
-
-This variable conditionally defines C<HAS_FLOCK> if flock() is
-available to do file locking.
-
-=item C<d_flockproto>
-
-From F<d_flockproto.U>:
-
-This variable conditionally defines the C<HAS_FLOCK_PROTO> symbol,
-which indicates to the C program that the system provides
-a prototype for the flock() function. Otherwise, it is
-up to the program to supply one.
-
-=item C<d_fma>
-
-From F<d_fma.U>:
-
-This variable conditionally defines the C<HAS_FMA> symbol, which
-indicates to the C program that the fma() routine is available.
-
-=item C<d_fmax>
-
-From F<d_fmax.U>:
-
-This variable conditionally defines the C<HAS_FMAX> symbol, which
-indicates to the C program that the fmax() routine is available.
-
-=item C<d_fmin>
-
-From F<d_fmin.U>:
-
-This variable conditionally defines the C<HAS_FMIN> symbol, which
-indicates to the C program that the fmin() routine is available.
-
-=item C<d_fork>
-
-From F<d_fork.U>:
-
-This variable conditionally defines the C<HAS_FORK> symbol, which
-indicates to the C program that the fork() routine is available.
-
-=item C<d_fp_class>
-
-From F<d_fp_class.U>:
-
-This variable conditionally defines the C<HAS_FP_CLASS> symbol, which
-indicates to the C program that the fp_class() routine is available.
-
-=item C<d_fp_classify>
-
-From F<d_fpclassify.U>:
-
-This variable conditionally defines the C<HAS_FP_CLASSIFY> symbol, which
-indicates to the C program that the fp_classify() routine is available.
-
-=item C<d_fp_classl>
-
-From F<d_fp_classl.U>:
-
-This variable conditionally defines the C<HAS_FP_CLASSL> symbol, which
-indicates to the C program that the fp_classl() routine is available.
-
-=item C<d_fpathconf>
-
-From F<d_pathconf.U>:
-
-This variable conditionally defines the C<HAS_FPATHCONF> symbol, which
-indicates to the C program that the pathconf() routine is available
-to determine file-system related limits and options associated
-with a given open file descriptor.
-
-=item C<d_fpclass>
-
-From F<d_fpclass.U>:
-
-This variable conditionally defines the C<HAS_FPCLASS> symbol, which
-indicates to the C program that the fpclass() routine is available.
-
-=item C<d_fpclassify>
-
-From F<d_fpclassify.U>:
-
-This variable conditionally defines the C<HAS_FPCLASSIFY> symbol, which
-indicates to the C program that the fpclassify() routine is available.
-
-=item C<d_fpclassl>
-
-From F<d_fpclassl.U>:
-
-This variable conditionally defines the C<HAS_FPCLASSL> symbol, which
-indicates to the C program that the fpclassl() routine is available.
-
-=item C<d_fpgetround>
-
-From F<d_fpgetround.U>:
-
-This variable conditionally defines C<HAS_FPGETROUND> if fpgetround()
-is available to get the floating point rounding mode.
-
-=item C<d_fpos64_t>
-
-From F<d_fpos64_t.U>:
-
-This symbol will be defined if the C compiler supports fpos64_t.
-
-=item C<d_freelocale>
-
-From F<d_newlocale.U>:
-
-This variable conditionally defines the C<HAS_FREELOCALE> symbol, which
-indicates to the C program that the freelocale() routine is available
-to deallocates the resources associated with a locale object.
-
-=item C<d_frexpl>
-
-From F<d_frexpl.U>:
-
-This variable conditionally defines the C<HAS_FREXPL> symbol, which
-indicates to the C program that the frexpl() routine is available.
-
-=item C<d_fs_data_s>
-
-From F<d_fs_data_s.U>:
-
-This variable conditionally defines the C<HAS_STRUCT_FS_DATA> symbol,
-which indicates that the struct fs_data is supported.
-
-=item C<d_fseeko>
-
-From F<d_fseeko.U>:
-
-This variable conditionally defines the C<HAS_FSEEKO> symbol, which
-indicates to the C program that the fseeko() routine is available.
-
-=item C<d_fsetpos>
-
-From F<d_fsetpos.U>:
-
-This variable conditionally defines C<HAS_FSETPOS> if fsetpos() is
-available to set the file position indicator.
-
-=item C<d_fstatfs>
-
-From F<d_fstatfs.U>:
-
-This variable conditionally defines the C<HAS_FSTATFS> symbol, which
-indicates to the C program that the fstatfs() routine is available.
-
-=item C<d_fstatvfs>
-
-From F<d_statvfs.U>:
-
-This variable conditionally defines the C<HAS_FSTATVFS> symbol, which
-indicates to the C program that the fstatvfs() routine is available.
-
-=item C<d_fsync>
-
-From F<d_fsync.U>:
-
-This variable conditionally defines the C<HAS_FSYNC> symbol, which
-indicates to the C program that the fsync() routine is available.
-
-=item C<d_ftello>
-
-From F<d_ftello.U>:
-
-This variable conditionally defines the C<HAS_FTELLO> symbol, which
-indicates to the C program that the ftello() routine is available.
-
-=item C<d_ftime>
-
-From F<d_ftime.U>:
-
-This variable conditionally defines the C<HAS_FTIME> symbol, which indicates
-that the ftime() routine exists. The ftime() routine is basically
-a sub-second accuracy clock.
-
-=item C<d_futimes>
-
-From F<d_futimes.U>:
-
-This variable conditionally defines the C<HAS_FUTIMES> symbol, which
-indicates to the C program that the futimes() routine is available.
-
-=item C<d_gai_strerror>
-
-From F<d_gai_strerror.U>:
-
-This variable conditionally defines the C<HAS_GAI_STRERROR> symbol
-if the gai_strerror() routine is available and can be used to
-translate error codes returned by getaddrinfo() into human
-readable strings.
-
-=item C<d_Gconvert>
-
-From F<d_gconvert.U>:
-
-This variable holds what Gconvert is defined as to convert
-floating point numbers into strings. By default, Configure
-sets C<this> macro to use the first of gconvert, gcvt, or sprintf
-that pass sprintf-%g-like behavior tests. If perl is using
-long doubles, the macro uses the first of the following
-functions that pass Configure's tests: qgcvt, sprintf (if
-Configure knows how to make sprintf format long doubles--see
-sPRIgldbl), gconvert, gcvt, and sprintf (casting to double).
-The gconvert_preference and gconvert_ld_preference variables
-can be used to alter Configure's preferences, for doubles and
-long doubles, respectively. If present, they contain a
-space-separated list of one or more of the above function
-names in the order they should be tried.
-
-d_Gconvert may be set to override Configure with a platform-
-specific function. If this function expects a double, a
-different value may need to be set by the F<uselongdouble.cbu>
-call-back unit so that long doubles can be formatted without
-loss of precision.
-
-=item C<d_gdbm_ndbm_h_uses_prototypes>
-
-From F<i_ndbm.U>:
-
-This variable conditionally defines the C<NDBM_H_USES_PROTOTYPES> symbol,
-which indicates that the gdbm-F<ndbm.h> include file uses real C<ANSI> C
-prototypes instead of K&R style function declarations. K&R style
-declarations are unsupported in C++, so the include file requires
-special handling when using a C++ compiler and this variable is
-undefined. Consult the different d_*ndbm_h_uses_prototypes variables
-to get the same information for alternative F<ndbm.h> include files.
-
-=item C<d_gdbmndbm_h_uses_prototypes>
-
-From F<i_ndbm.U>:
-
-This variable conditionally defines the C<NDBM_H_USES_PROTOTYPES> symbol,
-which indicates that the F<gdbm/ndbm.h> include file uses real C<ANSI> C
-prototypes instead of K&R style function declarations. K&R style
-declarations are unsupported in C++, so the include file requires
-special handling when using a C++ compiler and this variable is
-undefined. Consult the different d_*ndbm_h_uses_prototypes variables
-to get the same information for alternative F<ndbm.h> include files.
-
-=item C<d_getaddrinfo>
-
-From F<d_getaddrinfo.U>:
-
-This variable conditionally defines the C<HAS_GETADDRINFO> symbol,
-which indicates to the C program that the getaddrinfo() function
-is available.
-
-=item C<d_getcwd>
-
-From F<d_getcwd.U>:
-
-This variable conditionally defines the C<HAS_GETCWD> symbol, which
-indicates to the C program that the getcwd() routine is available
-to get the current working directory.
-
-=item C<d_getespwnam>
-
-From F<d_getespwnam.U>:
-
-This variable conditionally defines C<HAS_GETESPWNAM> if getespwnam() is
-available to retrieve enhanced (shadow) password entries by name.
-
-=item C<d_getfsstat>
-
-From F<d_getfsstat.U>:
-
-This variable conditionally defines the C<HAS_GETFSSTAT> symbol, which
-indicates to the C program that the getfsstat() routine is available.
-
-=item C<d_getgrent>
-
-From F<d_getgrent.U>:
-
-This variable conditionally defines the C<HAS_GETGRENT> symbol, which
-indicates to the C program that the getgrent() routine is available
-for sequential access of the group database.
-
-=item C<d_getgrent_r>
-
-From F<d_getgrent_r.U>:
-
-This variable conditionally defines the C<HAS_GETGRENT_R> symbol,
-which indicates to the C program that the getgrent_r()
-routine is available.
-
-=item C<d_getgrgid_r>
-
-From F<d_getgrgid_r.U>:
-
-This variable conditionally defines the C<HAS_GETGRGID_R> symbol,
-which indicates to the C program that the getgrgid_r()
-routine is available.
-
-=item C<d_getgrnam_r>
-
-From F<d_getgrnam_r.U>:
-
-This variable conditionally defines the C<HAS_GETGRNAM_R> symbol,
-which indicates to the C program that the getgrnam_r()
-routine is available.
-
-=item C<d_getgrps>
-
-From F<d_getgrps.U>:
-
-This variable conditionally defines the C<HAS_GETGROUPS> symbol, which
-indicates to the C program that the getgroups() routine is available
-to get the list of process groups.
-
-=item C<d_gethbyaddr>
-
-From F<d_gethbyad.U>:
-
-This variable conditionally defines the C<HAS_GETHOSTBYADDR> symbol, which
-indicates to the C program that the gethostbyaddr() routine is available
-to look up hosts by their C<IP> addresses.
-
-=item C<d_gethbyname>
-
-From F<d_gethbynm.U>:
-
-This variable conditionally defines the C<HAS_GETHOSTBYNAME> symbol, which
-indicates to the C program that the gethostbyname() routine is available
-to look up host names in some data base or other.
-
-=item C<d_gethent>
-
-From F<d_gethent.U>:
-
-This variable conditionally defines C<HAS_GETHOSTENT> if gethostent() is
-available to look up host names in some data base or another.
-
-=item C<d_gethname>
-
-From F<d_gethname.U>:
-
-This variable conditionally defines the C<HAS_GETHOSTNAME> symbol, which
-indicates to the C program that the gethostname() routine may be
-used to derive the host name.
-
-=item C<d_gethostbyaddr_r>
-
-From F<d_gethostbyaddr_r.U>:
-
-This variable conditionally defines the C<HAS_GETHOSTBYADDR_R> symbol,
-which indicates to the C program that the gethostbyaddr_r()
-routine is available.
-
-=item C<d_gethostbyname_r>
-
-From F<d_gethostbyname_r.U>:
-
-This variable conditionally defines the C<HAS_GETHOSTBYNAME_R> symbol,
-which indicates to the C program that the gethostbyname_r()
-routine is available.
-
-=item C<d_gethostent_r>
-
-From F<d_gethostent_r.U>:
-
-This variable conditionally defines the C<HAS_GETHOSTENT_R> symbol,
-which indicates to the C program that the gethostent_r()
-routine is available.
-
-=item C<d_gethostprotos>
-
-From F<d_gethostprotos.U>:
-
-This variable conditionally defines the C<HAS_GETHOST_PROTOS> symbol,
-which indicates to the C program that <netdb.h> supplies
-prototypes for the various gethost*() functions.
-See also F<netdbtype.U> for probing for various netdb types.
-
-=item C<d_getitimer>
-
-From F<d_getitimer.U>:
-
-This variable conditionally defines the C<HAS_GETITIMER> symbol, which
-indicates to the C program that the getitimer() routine is available.
-
-=item C<d_getlogin>
-
-From F<d_getlogin.U>:
-
-This variable conditionally defines the C<HAS_GETLOGIN> symbol, which
-indicates to the C program that the getlogin() routine is available
-to get the login name.
-
-=item C<d_getlogin_r>
-
-From F<d_getlogin_r.U>:
-
-This variable conditionally defines the C<HAS_GETLOGIN_R> symbol,
-which indicates to the C program that the getlogin_r()
-routine is available.
-
-=item C<d_getmnt>
-
-From F<d_getmnt.U>:
-
-This variable conditionally defines the C<HAS_GETMNT> symbol, which
-indicates to the C program that the getmnt() routine is available
-to retrieve one or more mount info blocks by filename.
-
-=item C<d_getmntent>
-
-From F<d_getmntent.U>:
-
-This variable conditionally defines the C<HAS_GETMNTENT> symbol, which
-indicates to the C program that the getmntent() routine is available
-to iterate through mounted files to get their mount info.
-
-=item C<d_getnameinfo>
-
-From F<d_getnameinfo.U>:
-
-This variable conditionally defines the C<HAS_GETNAMEINFO> symbol,
-which indicates to the C program that the getnameinfo() function
-is available.
-
-=item C<d_getnbyaddr>
-
-From F<d_getnbyad.U>:
-
-This variable conditionally defines the C<HAS_GETNETBYADDR> symbol, which
-indicates to the C program that the getnetbyaddr() routine is available
-to look up networks by their C<IP> addresses.
-
-=item C<d_getnbyname>
-
-From F<d_getnbynm.U>:
-
-This variable conditionally defines the C<HAS_GETNETBYNAME> symbol, which
-indicates to the C program that the getnetbyname() routine is available
-to look up networks by their names.
-
-=item C<d_getnent>
-
-From F<d_getnent.U>:
-
-This variable conditionally defines C<HAS_GETNETENT> if getnetent() is
-available to look up network names in some data base or another.
-
-=item C<d_getnetbyaddr_r>
-
-From F<d_getnetbyaddr_r.U>:
-
-This variable conditionally defines the C<HAS_GETNETBYADDR_R> symbol,
-which indicates to the C program that the getnetbyaddr_r()
-routine is available.
-
-=item C<d_getnetbyname_r>
-
-From F<d_getnetbyname_r.U>:
-
-This variable conditionally defines the C<HAS_GETNETBYNAME_R> symbol,
-which indicates to the C program that the getnetbyname_r()
-routine is available.
-
-=item C<d_getnetent_r>
-
-From F<d_getnetent_r.U>:
-
-This variable conditionally defines the C<HAS_GETNETENT_R> symbol,
-which indicates to the C program that the getnetent_r()
-routine is available.
-
-=item C<d_getnetprotos>
-
-From F<d_getnetprotos.U>:
-
-This variable conditionally defines the C<HAS_GETNET_PROTOS> symbol,
-which indicates to the C program that <netdb.h> supplies
-prototypes for the various getnet*() functions.
-See also F<netdbtype.U> for probing for various netdb types.
-
-=item C<d_getpagsz>
-
-From F<d_getpagsz.U>:
-
-This variable conditionally defines C<HAS_GETPAGESIZE> if getpagesize()
-is available to get the system page size.
-
-=item C<d_getpbyname>
-
-From F<d_getprotby.U>:
-
-This variable conditionally defines the C<HAS_GETPROTOBYNAME>
-symbol, which indicates to the C program that the
-getprotobyname() routine is available to look up protocols
-by their name.
-
-=item C<d_getpbynumber>
-
-From F<d_getprotby.U>:
-
-This variable conditionally defines the C<HAS_GETPROTOBYNUMBER>
-symbol, which indicates to the C program that the
-getprotobynumber() routine is available to look up protocols
-by their number.
-
-=item C<d_getpent>
-
-From F<d_getpent.U>:
-
-This variable conditionally defines C<HAS_GETPROTOENT> if getprotoent() is
-available to look up protocols in some data base or another.
-
-=item C<d_getpgid>
-
-From F<d_getpgid.U>:
-
-This variable conditionally defines the C<HAS_GETPGID> symbol, which
-indicates to the C program that the getpgid(pid) function
-is available to get the process group id.
-
-=item C<d_getpgrp>
-
-From F<d_getpgrp.U>:
-
-This variable conditionally defines C<HAS_GETPGRP> if getpgrp() is
-available to get the current process group.
-
-=item C<d_getpgrp2>
-
-From F<d_getpgrp2.U>:
-
-This variable conditionally defines the HAS_GETPGRP2 symbol, which
-indicates to the C program that the getpgrp2() (as in F<DG/C<UX>>) routine
-is available to get the current process group.
-
-=item C<d_getppid>
-
-From F<d_getppid.U>:
-
-This variable conditionally defines the C<HAS_GETPPID> symbol, which
-indicates to the C program that the getppid() routine is available
-to get the parent process C<ID>.
-
-=item C<d_getprior>
-
-From F<d_getprior.U>:
-
-This variable conditionally defines C<HAS_GETPRIORITY> if getpriority()
-is available to get a process's priority.
-
-=item C<d_getprotobyname_r>
-
-From F<d_getprotobyname_r.U>:
-
-This variable conditionally defines the C<HAS_GETPROTOBYNAME_R> symbol,
-which indicates to the C program that the getprotobyname_r()
-routine is available.
-
-=item C<d_getprotobynumber_r>
-
-From F<d_getprotobynumber_r.U>:
-
-This variable conditionally defines the C<HAS_GETPROTOBYNUMBER_R> symbol,
-which indicates to the C program that the getprotobynumber_r()
-routine is available.
-
-=item C<d_getprotoent_r>
-
-From F<d_getprotoent_r.U>:
-
-This variable conditionally defines the C<HAS_GETPROTOENT_R> symbol,
-which indicates to the C program that the getprotoent_r()
-routine is available.
-
-=item C<d_getprotoprotos>
-
-From F<d_getprotoprotos.U>:
-
-This variable conditionally defines the C<HAS_GETPROTO_PROTOS> symbol,
-which indicates to the C program that <netdb.h> supplies
-prototypes for the various getproto*() functions.
-See also F<netdbtype.U> for probing for various netdb types.
-
-=item C<d_getprpwnam>
-
-From F<d_getprpwnam.U>:
-
-This variable conditionally defines C<HAS_GETPRPWNAM> if getprpwnam() is
-available to retrieve protected (shadow) password entries by name.
-
-=item C<d_getpwent>
-
-From F<d_getpwent.U>:
-
-This variable conditionally defines the C<HAS_GETPWENT> symbol, which
-indicates to the C program that the getpwent() routine is available
-for sequential access of the passwd database.
-
-=item C<d_getpwent_r>
-
-From F<d_getpwent_r.U>:
-
-This variable conditionally defines the C<HAS_GETPWENT_R> symbol,
-which indicates to the C program that the getpwent_r()
-routine is available.
-
-=item C<d_getpwnam_r>
-
-From F<d_getpwnam_r.U>:
-
-This variable conditionally defines the C<HAS_GETPWNAM_R> symbol,
-which indicates to the C program that the getpwnam_r()
-routine is available.
-
-=item C<d_getpwuid_r>
-
-From F<d_getpwuid_r.U>:
-
-This variable conditionally defines the C<HAS_GETPWUID_R> symbol,
-which indicates to the C program that the getpwuid_r()
-routine is available.
-
-=item C<d_getsbyname>
-
-From F<d_getsrvby.U>:
-
-This variable conditionally defines the C<HAS_GETSERVBYNAME>
-symbol, which indicates to the C program that the
-getservbyname() routine is available to look up services
-by their name.
-
-=item C<d_getsbyport>
-
-From F<d_getsrvby.U>:
-
-This variable conditionally defines the C<HAS_GETSERVBYPORT>
-symbol, which indicates to the C program that the
-getservbyport() routine is available to look up services
-by their port.
-
-=item C<d_getsent>
-
-From F<d_getsent.U>:
-
-This variable conditionally defines C<HAS_GETSERVENT> if getservent() is
-available to look up network services in some data base or another.
-
-=item C<d_getservbyname_r>
-
-From F<d_getservbyname_r.U>:
-
-This variable conditionally defines the C<HAS_GETSERVBYNAME_R> symbol,
-which indicates to the C program that the getservbyname_r()
-routine is available.
-
-=item C<d_getservbyport_r>
-
-From F<d_getservbyport_r.U>:
-
-This variable conditionally defines the C<HAS_GETSERVBYPORT_R> symbol,
-which indicates to the C program that the getservbyport_r()
-routine is available.
-
-=item C<d_getservent_r>
-
-From F<d_getservent_r.U>:
-
-This variable conditionally defines the C<HAS_GETSERVENT_R> symbol,
-which indicates to the C program that the getservent_r()
-routine is available.
-
-=item C<d_getservprotos>
-
-From F<d_getservprotos.U>:
-
-This variable conditionally defines the C<HAS_GETSERV_PROTOS> symbol,
-which indicates to the C program that <netdb.h> supplies
-prototypes for the various getserv*() functions.
-See also F<netdbtype.U> for probing for various netdb types.
-
-=item C<d_getspnam>
-
-From F<d_getspnam.U>:
-
-This variable conditionally defines C<HAS_GETSPNAM> if getspnam() is
-available to retrieve SysV shadow password entries by name.
-
-=item C<d_getspnam_r>
-
-From F<d_getspnam_r.U>:
-
-This variable conditionally defines the C<HAS_GETSPNAM_R> symbol,
-which indicates to the C program that the getspnam_r()
-routine is available.
-
-=item C<d_gettimeod>
-
-From F<d_ftime.U>:
-
-This variable conditionally defines the C<HAS_GETTIMEOFDAY> symbol, which
-indicates that the gettimeofday() system call exists (to obtain a
-sub-second accuracy clock). You should probably include <sys/resource.h>.
-
-=item C<d_gmtime64>
-
-From F<d_timefuncs64.U>:
-
-This variable conditionally defines the HAS_GMTIME64 symbol, which
-indicates to the C program that the gmtime64 () routine is available.
-
-=item C<d_gmtime_r>
-
-From F<d_gmtime_r.U>:
-
-This variable conditionally defines the C<HAS_GMTIME_R> symbol,
-which indicates to the C program that the gmtime_r()
-routine is available.
-
-=item C<d_gnulibc>
-
-From F<d_gnulibc.U>:
-
-Defined if we're dealing with the C<GNU> C Library.
-
-=item C<d_grpasswd>
-
-From F<i_grp.U>:
-
-This variable conditionally defines C<GRPASSWD>, which indicates
-that struct group in <grp.h> contains gr_passwd.
-
-=item C<d_has_C_UTF8>
-
-From F<d_setlocale.U>:
-
-This variable is set to either C<true> or C<false> depending on
-whether the compilation system supports the F<C.UTF>-8 locale.
-
-=item C<d_hasmntopt>
-
-From F<d_hasmntopt.U>:
-
-This variable conditionally defines the C<HAS_HASMNTOPT> symbol, which
-indicates to the C program that the hasmntopt() routine is available
-to query the mount options of file systems.
-
-=item C<d_htonl>
-
-From F<d_htonl.U>:
-
-This variable conditionally defines C<HAS_HTONL> if htonl() and its
-friends are available to do network order byte swapping.
-
-=item C<d_hypot>
-
-From F<d_hypot.U>:
-
-This variable conditionally defines C<HAS_HYPOT> if hypot is available
-for numerically stable hypotenuse function.
-
-=item C<d_ilogb>
-
-From F<d_ilogb.U>:
-
-This variable conditionally defines the C<HAS_ILOGB> symbol, which
-indicates to the C program that the ilogb() routine is available
-for extracting the exponent of double x as a signed integer.
-
-=item C<d_ilogbl>
-
-From F<d_ilogbl.U>:
-
-This variable conditionally defines the C<HAS_ILOGBL> symbol, which
-indicates to the C program that the ilogbl() routine is available
-for extracting the exponent of long double x as a signed integer.
-If scalbnl is also present we can emulate frexpl.
-
-=item C<d_inc_version_list>
-
-From F<inc_version_list.U>:
-
-This variable conditionally defines C<PERL_INC_VERSION_LIST>.
-It is set to undef when C<PERL_INC_VERSION_LIST> is empty.
-
-=item C<d_inetaton>
-
-From F<d_inetaton.U>:
-
-This variable conditionally defines the C<HAS_INET_ATON> symbol, which
-indicates to the C program that the inet_aton() function is available
-to parse C<IP> address C<dotted-quad> strings.
-
-=item C<d_inetntop>
-
-From F<d_inetntop.U>:
-
-This variable conditionally defines the C<HAS_INETNTOP> symbol,
-which indicates to the C program that the inet_ntop() function
-is available.
-
-=item C<d_inetpton>
-
-From F<d_inetpton.U>:
-
-This variable conditionally defines the C<HAS_INETPTON> symbol,
-which indicates to the C program that the inet_pton() function
-is available.
-
-=item C<d_int64_t>
-
-From F<d_int64_t.U>:
-
-This symbol will be defined if the C compiler supports int64_t.
-
-=item C<d_ip_mreq>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the C<HAS_IP_MREQ> symbol, which
-indicates the availability of a struct ip_mreq.
-
-=item C<d_ip_mreq_source>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the C<HAS_IP_MREQ_SOURCE> symbol,
-which indicates the availability of a struct ip_mreq_source.
-
-=item C<d_ipv6_mreq>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the HAS_IPV6_MREQ symbol, which
-indicates the availability of a struct ipv6_mreq.
-
-=item C<d_ipv6_mreq_source>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the HAS_IPV6_MREQ_SOURCE symbol,
-which indicates the availability of a struct ipv6_mreq_source.
-
-=item C<d_isascii>
-
-From F<d_isascii.U>:
-
-This variable conditionally defines the C<HAS_ISASCII> constant,
-which indicates to the C program that isascii() is available.
-
-=item C<d_isblank>
-
-From F<d_isblank.U>:
-
-This variable conditionally defines the C<HAS_ISBLANK> constant,
-which indicates to the C program that isblank() is available.
-
-=item C<d_isfinite>
-
-From F<d_isfinite.U>:
-
-This variable conditionally defines the C<HAS_ISFINITE> symbol, which
-indicates to the C program that the isfinite() routine is available.
-
-=item C<d_isfinitel>
-
-From F<d_isfinitel.U>:
-
-This variable conditionally defines the C<HAS_ISFINITEL> symbol, which
-indicates to the C program that the isfinitel() routine is available.
-
-=item C<d_isinf>
-
-From F<d_isinf.U>:
-
-This variable conditionally defines the C<HAS_ISINF> symbol, which
-indicates to the C program that the isinf() routine is available.
-
-=item C<d_isinfl>
-
-From F<d_isinfl.U>:
-
-This variable conditionally defines the C<HAS_ISINFL> symbol, which
-indicates to the C program that the isinfl() routine is available.
-
-=item C<d_isless>
-
-From F<d_isless.U>:
-
-This variable conditionally defines the C<HAS_ISLESS> symbol, which
-indicates to the C program that the isless() routine is available.
-
-=item C<d_isnan>
-
-From F<d_isnan.U>:
-
-This variable conditionally defines the C<HAS_ISNAN> symbol, which
-indicates to the C program that the isnan() routine is available.
-
-=item C<d_isnanl>
-
-From F<d_isnanl.U>:
-
-This variable conditionally defines the C<HAS_ISNANL> symbol, which
-indicates to the C program that the isnanl() routine is available.
-
-=item C<d_isnormal>
-
-From F<d_isnormal.U>:
-
-This variable conditionally defines the C<HAS_ISNORMAL> symbol, which
-indicates to the C program that the isnormal() routine is available.
-
-=item C<d_j0>
-
-From F<d_j0.U>:
-
-This variable conditionally defines the HAS_J0 symbol, which
-indicates to the C program that the j0() routine is available.
-
-=item C<d_j0l>
-
-From F<d_j0.U>:
-
-This variable conditionally defines the HAS_J0L symbol, which
-indicates to the C program that the j0l() routine is available.
-
-=item C<d_killpg>
-
-From F<d_killpg.U>:
-
-This variable conditionally defines the C<HAS_KILLPG> symbol, which
-indicates to the C program that the killpg() routine is available
-to kill process groups.
-
-=item C<d_lc_monetary_2008>
-
-From F<d_lc_monetary_2008.U>:
-
-This variable conditionally defines HAS_LC_MONETARY_2008 if libc
-has the international currency locale rules from C<POSIX>
-1003.1-2008.
-
-=item C<d_lchown>
-
-From F<d_lchown.U>:
-
-This variable conditionally defines the C<HAS_LCHOWN> symbol, which
-indicates to the C program that the lchown() routine is available
-to operate on a symbolic link (instead of following the link).
-
-=item C<d_ldbl_dig>
-
-From F<d_ldbl_dig.U>:
-
-This variable conditionally defines d_ldbl_dig if this system's
-header files provide C<LDBL_DIG>, which is the number of significant
-digits in a long double precision number.
-
-=item C<d_ldexpl>
-
-From F<d_longdbl.U>:
-
-This variable conditionally defines the C<HAS_LDEXPL> symbol, which
-indicates to the C program that the ldexpl() routine is available.
-
-=item C<d_lgamma>
-
-From F<d_lgamma.U>:
-
-This variable conditionally defines the C<HAS_LGAMMA> symbol, which
-indicates to the C program that the lgamma() routine is available
-for the log gamma function. See also d_tgamma and d_lgamma_r.
-
-=item C<d_lgamma_r>
-
-From F<d_lgamma_r.U>:
-
-This variable conditionally defines the C<HAS_LGAMMA_R> symbol, which
-indicates to the C program that the lgamma_r() routine is available
-for the log gamma function, without using the global signgam variable.
-
-=item C<d_libm_lib_version>
-
-From F<d_libm_lib_version.U>:
-
-This variable conditionally defines the C<LIBM_LIB_VERSION> symbol,
-which indicates to the C program that F<math.h> defines C<_LIB_VERSION>
-being available in libm
-
-=item C<d_libname_unique>
-
-From F<so.U>:
-
-This variable is defined if the target system insists on unique
-basenames for shared library files. This is currently true on Android,
-false everywhere else we know of.
-Defaults to C<undef>.
-
-=item C<d_link>
-
-From F<d_link.U>:
-
-This variable conditionally defines C<HAS_LINK> if link() is
-available to create hard links.
-
-=item C<d_linkat>
-
-From F<d_fsat.U>:
-
-This variable conditionally defines the C<HAS_LINKAT> symbol, which
-indicates the C<POSIX> linkat() function is available.
-
-=item C<d_llrint>
-
-From F<d_llrint.U>:
-
-This variable conditionally defines the C<HAS_LLRINT> symbol, which
-indicates to the C program that the llrint() routine is available
-to return the long long value closest to a double (according
-to the current rounding mode).
-
-=item C<d_llrintl>
-
-From F<d_llrintl.U>:
-
-This variable conditionally defines the C<HAS_LLRINTL> symbol, which
-indicates to the C program that the llrintl() routine is available
-to return the long long value closest to a long double (according
-to the current rounding mode).
-
-=item C<d_llround>
-
-From F<d_llround.U>:
-
-This variable conditionally defines the C<HAS_LLROUND> symbol, which
-indicates to the C program that the llround() routine is available
-to return the long long value nearest to x.
-
-=item C<d_llroundl>
-
-From F<d_llroundl.U>:
-
-This variable conditionally defines the C<HAS_LLROUNDL> symbol, which
-indicates to the C program that the llroundl() routine is available
-to return the long long value nearest to x away from zero.
-
-=item C<d_localeconv_l>
-
-From F<d_localeconv_l.U>:
-
-This variable conditionally defines the C<HAS_LOCALECONV_L> symbol, which
-indicates to the C program that the localeconv_l() routine is available.
-
-=item C<d_localtime64>
-
-From F<d_timefuncs64.U>:
-
-This variable conditionally defines the HAS_LOCALTIME64 symbol, which
-indicates to the C program that the localtime64 () routine is available.
-
-=item C<d_localtime_r>
-
-From F<d_localtime_r.U>:
-
-This variable conditionally defines the C<HAS_LOCALTIME_R> symbol,
-which indicates to the C program that the localtime_r()
-routine is available.
-
-=item C<d_localtime_r_needs_tzset>
-
-From F<d_localtime_r.U>:
-
-This variable conditionally defines the C<LOCALTIME_R_NEEDS_TZSET>
-symbol, which makes us call tzset before localtime_r()
-
-=item C<d_locconv>
-
-From F<d_locconv.U>:
-
-This variable conditionally defines C<HAS_LOCALECONV> if localeconv() is
-available for numeric and monetary formatting conventions.
-
-=item C<d_lockf>
-
-From F<d_lockf.U>:
-
-This variable conditionally defines C<HAS_LOCKF> if lockf() is
-available to do file locking.
-
-=item C<d_log1p>
-
-From F<d_log1p.U>:
-
-This variable conditionally defines the HAS_LOG1P symbol, which
-indicates to the C program that the logp1() routine is available
-to compute log(1 + x) for values of x close to zero.
-
-=item C<d_log2>
-
-From F<d_log2.U>:
-
-This variable conditionally defines the HAS_LOG2 symbol, which
-indicates to the C program that the log2() routine is available
-to compute log base two.
-
-=item C<d_logb>
-
-From F<d_logb.U>:
-
-This variable conditionally defines the C<HAS_LOGB> symbol, which
-indicates to the C program that the logb() routine is available
-to extract the exponent of x.
-
-=item C<d_long_double_style_ieee>
-
-From F<d_longdbl.U>:
-
-This variable conditionally defines C<LONG_DOUBLE_STYLE_IEEE>
-if the long double is any of the C<IEEE> 754 style long doubles:
-C<LONG_DOUBLE_STYLE_IEEE_STD>, C<LONG_DOUBLE_STYLE_IEEE_EXTENDED>,
-C<LONG_DOUBLE_STYLE_IEEE_DOUBLEDOUBLE>.
-
-=item C<d_long_double_style_ieee_doubledouble>
-
-From F<d_longdbl.U>:
-
-This variable conditionally defines C<LONG_DOUBLE_STYLE_IEEE_DOUBLEDOUBLE>
-if the long double is the 128-bit C<IEEE> 754 double-double.
-
-=item C<d_long_double_style_ieee_extended>
-
-From F<d_longdbl.U>:
-
-This variable conditionally defines C<LONG_DOUBLE_STYLE_IEEE_EXTENDED>
-if the long double is the 80-bit C<IEEE> 754 extended precision.
-Note that despite the C<extended> this is less than the C<std>,
-since thisis an extension of the double precision.
-
-=item C<d_long_double_style_ieee_std>
-
-From F<d_longdbl.U>:
-
-This variable conditionally defines C<LONG_DOUBLE_STYLE_IEEE_STD>
-if the long double is the 128-bit C<IEEE> 754.
-
-=item C<d_long_double_style_vax>
-
-From F<d_longdbl.U>:
-
-This variable conditionally defines C<LONG_DOUBLE_STYLE_VAX>
-if the long double is the 128-bit C<VAX> format H.
-
-=item C<d_longdbl>
-
-From F<d_longdbl.U>:
-
-This variable conditionally defines C<HAS_LONG_DOUBLE> if
-the long double type is supported.
-
-=item C<d_longlong>
-
-From F<d_longlong.U>:
-
-This variable conditionally defines C<HAS_LONG_LONG> if
-the long long type is supported.
-
-=item C<d_lrint>
-
-From F<d_lrint.U>:
-
-This variable conditionally defines the C<HAS_LRINT> symbol, which
-indicates to the C program that the lrint() routine is available
-to return the integral value closest to a double (according
-to the current rounding mode).
-
-=item C<d_lrintl>
-
-From F<d_lrintl.U>:
-
-This variable conditionally defines the C<HAS_LRINTL> symbol, which
-indicates to the C program that the lrintl() routine is available
-to return the integral value closest to a long double (according
-to the current rounding mode).
-
-=item C<d_lround>
-
-From F<d_lround.U>:
-
-This variable conditionally defines the C<HAS_LROUND> symbol, which
-indicates to the C program that the lround() routine is available
-to return the integral value nearest to x.
-
-=item C<d_lroundl>
-
-From F<d_lroundl.U>:
-
-This variable conditionally defines the C<HAS_LROUNDL> symbol, which
-indicates to the C program that the lroundl() routine is available
-to return the integral value nearest to x away from zero.
-
-=item C<d_lseekproto>
-
-From F<d_lseekproto.U>:
-
-This variable conditionally defines the C<HAS_LSEEK_PROTO> symbol,
-which indicates to the C program that the system provides
-a prototype for the lseek() function. Otherwise, it is
-up to the program to supply one.
-
-=item C<d_lstat>
-
-From F<d_lstat.U>:
-
-This variable conditionally defines C<HAS_LSTAT> if lstat() is
-available to do file stats on symbolic links.
-
-=item C<d_madvise>
-
-From F<d_madvise.U>:
-
-This variable conditionally defines C<HAS_MADVISE> if madvise() is
-available to map a file into memory.
-
-=item C<d_malloc_good_size>
-
-From F<d_malloc_size.U>:
-
-This symbol, if defined, indicates that the malloc_good_size
-routine is available for use.
-
-=item C<d_malloc_size>
-
-From F<d_malloc_size.U>:
-
-This symbol, if defined, indicates that the malloc_size
-routine is available for use.
-
-=item C<d_mblen>
-
-From F<d_mblen.U>:
-
-This variable conditionally defines the C<HAS_MBLEN> symbol, which
-indicates to the C program that the mblen() routine is available
-to find the number of bytes in a multibye character.
-
-=item C<d_mbrlen>
-
-From F<d_mbrlen.U>:
-
-This variable conditionally defines the C<HAS_MBRLEN> symbol if the
-mbrlen() routine is available to be used to get the length of
-multi-byte character strings.
-
-=item C<d_mbrtowc>
-
-From F<d_mbrtowc.U>:
-
-This variable conditionally defines the C<HAS_MBRTOWC> symbol if the
-mbrtowc() routine is available to be used to convert a multi-byte
-character into a wide character.
-
-=item C<d_mbstowcs>
-
-From F<d_mbstowcs.U>:
-
-This variable conditionally defines the C<HAS_MBSTOWCS> symbol, which
-indicates to the C program that the mbstowcs() routine is available
-to convert a multibyte string into a wide character string.
-
-=item C<d_mbtowc>
-
-From F<d_mbtowc.U>:
-
-This variable conditionally defines the C<HAS_MBTOWC> symbol, which
-indicates to the C program that the mbtowc() routine is available
-to convert multibyte to a wide character.
-
-=item C<d_memmem>
-
-From F<d_memmem.U>:
-
-This variable conditionally defines the C<HAS_MEMMEM> symbol, which
-indicates to the C program that the memmem() routine is available
-to return a pointer to the start of the first occurance of a
-substring in a memory area (or C<NULL> if not found).
-
-=item C<d_memrchr>
-
-From F<d_memrchr.U>:
-
-This variable conditionally defines the C<HAS_MEMRCHR> symbol, which
-indicates to the C program that the memrchr() routine is available
-to return a pointer to the last occurrence of a byte in a memory
-area (or C<NULL> if not found).
-
-=item C<d_mkdir>
-
-From F<d_mkdir.U>:
-
-This variable conditionally defines the C<HAS_MKDIR> symbol, which
-indicates to the C program that the mkdir() routine is available
-to create F<directories.>.
-
-=item C<d_mkdtemp>
-
-From F<d_mkdtemp.U>:
-
-This variable conditionally defines the C<HAS_MKDTEMP> symbol, which
-indicates to the C program that the mkdtemp() routine is available
-to exclusively create a uniquely named temporary directory.
-
-=item C<d_mkfifo>
-
-From F<d_mkfifo.U>:
-
-This variable conditionally defines the C<HAS_MKFIFO> symbol, which
-indicates to the C program that the mkfifo() routine is available.
-
-=item C<d_mkostemp>
-
-From F<d_mkostemp.U>:
-
-This variable conditionally defines C<HAS_MKOSTEMP> if mkostemp() is
-available to exclusively create and open a uniquely named (with a
-suffix) temporary file.
-
-=item C<d_mkstemp>
-
-From F<d_mkstemp.U>:
-
-This variable conditionally defines the C<HAS_MKSTEMP> symbol, which
-indicates to the C program that the mkstemp() routine is available
-to exclusively create and open a uniquely named temporary file.
-
-=item C<d_mkstemps>
-
-From F<d_mkstemps.U>:
-
-This variable conditionally defines the C<HAS_MKSTEMPS> symbol, which
-indicates to the C program that the mkstemps() routine is available
-to exclusively create and open a uniquely named (with a suffix)
-temporary file.
-
-=item C<d_mktime>
-
-From F<d_mktime.U>:
-
-This variable conditionally defines the C<HAS_MKTIME> symbol, which
-indicates to the C program that the mktime() routine is available.
-
-=item C<d_mktime64>
-
-From F<d_timefuncs64.U>:
-
-This variable conditionally defines the HAS_MKTIME64 symbol, which
-indicates to the C program that the mktime64 () routine is available.
-
-=item C<d_mmap>
-
-From F<d_mmap.U>:
-
-This variable conditionally defines C<HAS_MMAP> if mmap() is
-available to map a file into memory.
-
-=item C<d_modfl>
-
-From F<d_modfl.U>:
-
-This variable conditionally defines the C<HAS_MODFL> symbol, which
-indicates to the C program that the modfl() routine is available.
-
-=item C<d_modflproto>
-
-From F<d_modfl.U>:
-
-This symbol, if defined, indicates that the system provides
-a prototype for the modfl() function. Otherwise, it is up
-to the program to supply one. C99 says it should be
-long double modfl(long double, long double *);
-
-=item C<d_mprotect>
-
-From F<d_mprotect.U>:
-
-This variable conditionally defines C<HAS_MPROTECT> if mprotect() is
-available to modify the access protection of a memory mapped file.
-
-=item C<d_msg>
-
-From F<d_msg.U>:
-
-This variable conditionally defines the C<HAS_MSG> symbol, which
-indicates that the entire msg*(2) library is present.
-
-=item C<d_msg_ctrunc>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the C<HAS_MSG_CTRUNC> symbol,
-which indicates that the C<MSG_CTRUNC> is available. #ifdef is
-not enough because it may be an enum, glibc has been known to do this.
-
-=item C<d_msg_dontroute>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the C<HAS_MSG_DONTROUTE> symbol,
-which indicates that the C<MSG_DONTROUTE> is available. #ifdef is
-not enough because it may be an enum, glibc has been known to do this.
-
-=item C<d_msg_oob>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the C<HAS_MSG_OOB> symbol,
-which indicates that the C<MSG_OOB> is available. #ifdef is
-not enough because it may be an enum, glibc has been known to do this.
-
-=item C<d_msg_peek>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the C<HAS_MSG_PEEK> symbol,
-which indicates that the C<MSG_PEEK> is available. #ifdef is
-not enough because it may be an enum, glibc has been known to do this.
-
-=item C<d_msg_proxy>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the C<HAS_MSG_PROXY> symbol,
-which indicates that the C<MSG_PROXY> is available. #ifdef is
-not enough because it may be an enum, glibc has been known to do this.
-
-=item C<d_msgctl>
-
-From F<d_msgctl.U>:
-
-This variable conditionally defines the C<HAS_MSGCTL> symbol, which
-indicates to the C program that the msgctl() routine is available.
-
-=item C<d_msgget>
-
-From F<d_msgget.U>:
-
-This variable conditionally defines the C<HAS_MSGGET> symbol, which
-indicates to the C program that the msgget() routine is available.
-
-=item C<d_msghdr_s>
-
-From F<d_msghdr_s.U>:
-
-This variable conditionally defines the C<HAS_STRUCT_MSGHDR> symbol,
-which indicates that the struct msghdr is supported.
-
-=item C<d_msgrcv>
-
-From F<d_msgrcv.U>:
-
-This variable conditionally defines the C<HAS_MSGRCV> symbol, which
-indicates to the C program that the msgrcv() routine is available.
-
-=item C<d_msgsnd>
-
-From F<d_msgsnd.U>:
-
-This variable conditionally defines the C<HAS_MSGSND> symbol, which
-indicates to the C program that the msgsnd() routine is available.
-
-=item C<d_msync>
-
-From F<d_msync.U>:
-
-This variable conditionally defines C<HAS_MSYNC> if msync() is
-available to synchronize a mapped file.
-
-=item C<d_munmap>
-
-From F<d_munmap.U>:
-
-This variable conditionally defines C<HAS_MUNMAP> if munmap() is
-available to unmap a region mapped by mmap().
-
-=item C<d_mymalloc>
-
-From F<mallocsrc.U>:
-
-This variable conditionally defines C<MYMALLOC> in case other parts
-of the source want to take special action if C<MYMALLOC> is used.
-This may include different sorts of profiling or error detection.
-
-=item C<d_nan>
-
-From F<d_nan.U>:
-
-This variable conditionally defines C<HAS_NAN> if nan() is
-available to generate NaN.
-
-=item C<d_nanosleep>
-
-From F<d_nanosleep.U>:
-
-This variable conditionally defines C<HAS_NANOSLEEP>
-if nanosleep() is available to sleep with 1E-9 sec accuracy.
-
-=item C<d_ndbm>
-
-From F<i_ndbm.U>:
-
-This variable conditionally defines the C<HAS_NDBM> symbol, which
-indicates that both the F<ndbm.h> include file and an appropriate ndbm
-library exist. Consult the different i_*ndbm variables
-to find out the actual include location. Sometimes, a system has the
-header file but not the library. This variable will only be set if
-the system has both.
-
-=item C<d_ndbm_h_uses_prototypes>
-
-From F<i_ndbm.U>:
-
-This variable conditionally defines the C<NDBM_H_USES_PROTOTYPES> symbol,
-which indicates that the F<ndbm.h> include file uses real C<ANSI> C
-prototypes instead of K&R style function declarations. K&R style
-declarations are unsupported in C++, so the include file requires
-special handling when using a C++ compiler and this variable is
-undefined. Consult the different d_*ndbm_h_uses_prototypes variables
-to get the same information for alternative F<ndbm.h> include files.
-
-=item C<d_nearbyint>
-
-From F<d_nearbyint.U>:
-
-This variable conditionally defines C<HAS_NEARBYINT> if nearbyint()
-is available to return the integral value closest to (according to
-the current rounding mode) to x.
-
-=item C<d_newlocale>
-
-From F<d_newlocale.U>:
-
-This variable conditionally defines the C<HAS_NEWLOCALE> symbol, which
-indicates to the C program that the newlocale() routine is available
-to return a new locale object or modify an existing locale object.
-
-=item C<d_nextafter>
-
-From F<d_nextafter.U>:
-
-This variable conditionally defines C<HAS_NEXTAFTER> if nextafter()
-is available to return the next machine representable double from
-x in direction y.
-
-=item C<d_nexttoward>
-
-From F<d_nexttoward.U>:
-
-This variable conditionally defines C<HAS_NEXTTOWARD> if nexttoward()
-is available to return the next machine representable long double from
-x in direction y.
-
-=item C<d_nice>
-
-From F<d_nice.U>:
-
-This variable conditionally defines the C<HAS_NICE> symbol, which
-indicates to the C program that the nice() routine is available.
-
-=item C<d_nl_langinfo>
-
-From F<d_nl_langinfo.U>:
-
-This variable conditionally defines the C<HAS_NL_LANGINFO> symbol, which
-indicates to the C program that the nl_langinfo() routine is available.
-
-=item C<d_nv_preserves_uv>
-
-From F<perlxv.U>:
-
-This variable indicates whether a variable of type nvtype
-can preserve all the bits a variable of type uvtype.
-
-=item C<d_nv_zero_is_allbits_zero>
-
-From F<perlxv.U>:
-
-This variable indicates whether a variable of type nvtype
-stores 0.0 in memory as all bits zero.
-
-=item C<d_off64_t>
-
-From F<d_off64_t.U>:
-
-This symbol will be defined if the C compiler supports off64_t.
-
-=item C<d_old_pthread_create_joinable>
-
-From F<d_pthrattrj.U>:
-
-This variable conditionally defines pthread_create_joinable.
-undef if F<pthread.h> defines C<PTHREAD_CREATE_JOINABLE>.
-
-=item C<d_oldpthreads>
-
-From F<usethreads.U>:
-
-This variable conditionally defines the C<OLD_PTHREADS_API> symbol,
-and indicates that Perl should be built to use the old
-draft C<POSIX> threads C<API>. This is only potentially meaningful if
-usethreads is set.
-
-=item C<d_oldsock>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the C<OLDSOCKET> symbol, which
-indicates that the C<BSD> socket interface is based on 4.1c and not 4.2.
-
-=item C<d_open3>
-
-From F<d_open3.U>:
-
-This variable conditionally defines the HAS_OPEN3 manifest constant,
-which indicates to the C program that the 3 argument version of
-the open(2) function is available.
-
-=item C<d_openat>
-
-From F<d_fsat.U>:
-
-This variable conditionally defines the C<HAS_OPENAT> symbol, which
-indicates the C<POSIX> openat() function is available.
-
-=item C<d_pathconf>
-
-From F<d_pathconf.U>:
-
-This variable conditionally defines the C<HAS_PATHCONF> symbol, which
-indicates to the C program that the pathconf() routine is available
-to determine file-system related limits and options associated
-with a given filename.
-
-=item C<d_pause>
-
-From F<d_pause.U>:
-
-This variable conditionally defines the C<HAS_PAUSE> symbol, which
-indicates to the C program that the pause() routine is available
-to suspend a process until a signal is received.
-
-=item C<d_perl_otherlibdirs>
-
-From F<otherlibdirs.U>:
-
-This variable conditionally defines C<PERL_OTHERLIBDIRS>, which
-contains a colon-separated set of paths for the perl binary to
-include in @C<INC>. See also otherlibdirs.
-
-=item C<d_phostname>
-
-From F<d_gethname.U>:
-
-This variable conditionally defines the C<HAS_PHOSTNAME> symbol, which
-contains the shell command which, when fed to popen(), may be
-used to derive the host name.
-
-=item C<d_pipe>
-
-From F<d_pipe.U>:
-
-This variable conditionally defines the C<HAS_PIPE> symbol, which
-indicates to the C program that the pipe() routine is available
-to create an inter-process channel.
-
-=item C<d_pipe2>
-
-From F<d_pipe2.U>:
-
-This variable conditionally defines the HAS_PIPE2 symbol, which
-indicates to the C program that the pipe2() routine is available
-to create an inter-process channel.
-
-=item C<d_poll>
-
-From F<d_poll.U>:
-
-This variable conditionally defines the C<HAS_POLL> symbol, which
-indicates to the C program that the poll() routine is available
-to poll active file descriptors.
-
-=item C<d_portable>
-
-From F<d_portable.U>:
-
-This variable conditionally defines the C<PORTABLE> symbol, which
-indicates to the C program that it should not assume that it is
-running on the machine it was compiled on.
-
-=item C<d_prctl>
-
-From F<d_prctl.U>:
-
-This variable conditionally defines the C<HAS_PRCTL> symbol, which
-indicates to the C program that the prctl() routine is available.
-Note that there are at least two prctl variants: Linux and Irix.
-While they are somewhat similar, they are incompatible.
-
-=item C<d_prctl_set_name>
-
-From F<d_prctl.U>:
-
-This variable conditionally defines the C<HAS_PRCTL_SET_NAME> symbol,
-which indicates to the C program that the prctl() routine supports
-the C<PR_SET_NAME> option.
-
-=item C<d_PRId64>
-
-From F<quadfio.U>:
-
-This variable conditionally defines the PERL_PRId64 symbol, which
-indicates that stdio has a symbol to print 64-bit decimal numbers.
-
-=item C<d_PRIeldbl>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the PERL_PRIfldbl symbol, which
-indicates that stdio has a symbol to print long doubles.
-
-=item C<d_PRIEUldbl>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the PERL_PRIfldbl symbol, which
-indicates that stdio has a symbol to print long doubles.
-The C<U> in the name is to separate this from d_PRIeldbl so that even
-case-blind systems can see the difference.
-
-=item C<d_PRIfldbl>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the PERL_PRIfldbl symbol, which
-indicates that stdio has a symbol to print long doubles.
-
-=item C<d_PRIFUldbl>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the PERL_PRIfldbl symbol, which
-indicates that stdio has a symbol to print long doubles.
-The C<U> in the name is to separate this from d_PRIfldbl so that even
-case-blind systems can see the difference.
-
-=item C<d_PRIgldbl>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the PERL_PRIfldbl symbol, which
-indicates that stdio has a symbol to print long doubles.
-
-=item C<d_PRIGUldbl>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the PERL_PRIfldbl symbol, which
-indicates that stdio has a symbol to print long doubles.
-The C<U> in the name is to separate this from d_PRIgldbl so that even
-case-blind systems can see the difference.
-
-=item C<d_PRIi64>
-
-From F<quadfio.U>:
-
-This variable conditionally defines the PERL_PRIi64 symbol, which
-indicates that stdio has a symbol to print 64-bit decimal numbers.
-
-=item C<d_printf_format_null>
-
-From F<d_attribut.U>:
-
-This variable conditionally defines C<PRINTF_FORMAT_NULL_OK>, which
-indicates the C compiler allows printf-like formats to be null.
-
-=item C<d_PRIo64>
-
-From F<quadfio.U>:
-
-This variable conditionally defines the PERL_PRIo64 symbol, which
-indicates that stdio has a symbol to print 64-bit octal numbers.
-
-=item C<d_PRIu64>
-
-From F<quadfio.U>:
-
-This variable conditionally defines the PERL_PRIu64 symbol, which
-indicates that stdio has a symbol to print 64-bit unsigned decimal
-numbers.
-
-=item C<d_PRIx64>
-
-From F<quadfio.U>:
-
-This variable conditionally defines the PERL_PRIx64 symbol, which
-indicates that stdio has a symbol to print 64-bit hexadecimal numbers.
-
-=item C<d_PRIXU64>
-
-From F<quadfio.U>:
-
-This variable conditionally defines the PERL_PRIXU64 symbol, which
-indicates that stdio has a symbol to print 64-bit hExADECimAl numbers.
-The C<U> in the name is to separate this from d_PRIx64 so that even
-case-blind systems can see the difference.
-
-=item C<d_procselfexe>
-
-From F<d_procselfexe.U>:
-
-Defined if $procselfexe is symlink to the absolute
-pathname of the executing program.
-
-=item C<d_pseudofork>
-
-From F<d_vfork.U>:
-
-This variable conditionally defines the C<HAS_PSEUDOFORK> symbol,
-which indicates that an emulation of the fork routine is available.
-
-=item C<d_pthread_atfork>
-
-From F<d_pthread_atfork.U>:
-
-This variable conditionally defines the C<HAS_PTHREAD_ATFORK> symbol,
-which indicates to the C program that the pthread_atfork()
-routine is available.
-
-=item C<d_pthread_attr_setscope>
-
-From F<d_pthread_attr_ss.U>:
-
-This variable conditionally defines C<HAS_PTHREAD_ATTR_SETSCOPE> if
-pthread_attr_setscope() is available to set the contention scope
-attribute of a thread attribute object.
-
-=item C<d_pthread_yield>
-
-From F<d_pthread_y.U>:
-
-This variable conditionally defines the C<HAS_PTHREAD_YIELD>
-symbol if the pthread_yield routine is available to yield
-the execution of the current thread.
-
-=item C<d_ptrdiff_t>
-
-From F<d_ptrdiff_t.U>:
-
-This symbol will be defined if the C compiler supports ptrdiff_t.
-
-=item C<d_pwage>
-
-From F<i_pwd.U>:
-
-This variable conditionally defines C<PWAGE>, which indicates
-that struct passwd contains pw_age.
-
-=item C<d_pwchange>
-
-From F<i_pwd.U>:
-
-This variable conditionally defines C<PWCHANGE>, which indicates
-that struct passwd contains pw_change.
-
-=item C<d_pwclass>
-
-From F<i_pwd.U>:
-
-This variable conditionally defines C<PWCLASS>, which indicates
-that struct passwd contains pw_class.
-
-=item C<d_pwcomment>
-
-From F<i_pwd.U>:
-
-This variable conditionally defines C<PWCOMMENT>, which indicates
-that struct passwd contains pw_comment.
-
-=item C<d_pwexpire>
-
-From F<i_pwd.U>:
-
-This variable conditionally defines C<PWEXPIRE>, which indicates
-that struct passwd contains pw_expire.
-
-=item C<d_pwgecos>
-
-From F<i_pwd.U>:
-
-This variable conditionally defines C<PWGECOS>, which indicates
-that struct passwd contains pw_gecos.
-
-=item C<d_pwpasswd>
-
-From F<i_pwd.U>:
-
-This variable conditionally defines C<PWPASSWD>, which indicates
-that struct passwd contains pw_passwd.
-
-=item C<d_pwquota>
-
-From F<i_pwd.U>:
-
-This variable conditionally defines C<PWQUOTA>, which indicates
-that struct passwd contains pw_quota.
-
-=item C<d_qgcvt>
-
-From F<d_qgcvt.U>:
-
-This variable conditionally defines the C<HAS_QGCVT> symbol, which
-indicates to the C program that the qgcvt() routine is available.
-
-=item C<d_quad>
-
-From F<quadtype.U>:
-
-This variable, if defined, tells that there's a 64-bit integer type,
-quadtype.
-
-=item C<d_querylocale>
-
-From F<d_newlocale.U>:
-
-This variable conditionally defines the C<HAS_QUERYLOCALE> symbol, which
-indicates to the C program that the querylocale() routine is available
-to return the name of the locale for a category mask.
-
-=item C<d_random_r>
-
-From F<d_random_r.U>:
-
-This variable conditionally defines the C<HAS_RANDOM_R> symbol,
-which indicates to the C program that the random_r()
-routine is available.
-
-=item C<d_re_comp>
-
-From F<d_regcmp.U>:
-
-This variable conditionally defines the C<HAS_RECOMP> symbol, which
-indicates to the C program that the re_comp() routine is available
-for regular pattern matching (usually on C<BSD>). If so, it is likely that
-re_exec() exists.
-
-=item C<d_readdir>
-
-From F<d_readdir.U>:
-
-This variable conditionally defines C<HAS_READDIR> if readdir() is
-available to read directory entries.
-
-=item C<d_readdir64_r>
-
-From F<d_readdir64_r.U>:
-
-This variable conditionally defines the HAS_READDIR64_R symbol,
-which indicates to the C program that the readdir64_r()
-routine is available.
-
-=item C<d_readdir_r>
-
-From F<d_readdir_r.U>:
-
-This variable conditionally defines the C<HAS_READDIR_R> symbol,
-which indicates to the C program that the readdir_r()
-routine is available.
-
-=item C<d_readlink>
-
-From F<d_readlink.U>:
-
-This variable conditionally defines the C<HAS_READLINK> symbol, which
-indicates to the C program that the readlink() routine is available
-to read the value of a symbolic link.
-
-=item C<d_readv>
-
-From F<d_readv.U>:
-
-This variable conditionally defines the C<HAS_READV> symbol, which
-indicates to the C program that the readv() routine is available.
-
-=item C<d_recvmsg>
-
-From F<d_recvmsg.U>:
-
-This variable conditionally defines the C<HAS_RECVMSG> symbol, which
-indicates to the C program that the recvmsg() routine is available.
-
-=item C<d_regcmp>
-
-From F<d_regcmp.U>:
-
-This variable conditionally defines the C<HAS_REGCMP> symbol, which
-indicates to the C program that the regcmp() routine is available
-for regular pattern matching (usually on System V).
-
-=item C<d_regcomp>
-
-From F<d_regcmp.U>:
-
-This variable conditionally defines the C<HAS_REGCOMP> symbol, which
-indicates to the C program that the regcomp() routine is available
-for regular pattern matching (usually on F<POSIX.2> conforming systems).
-
-=item C<d_remainder>
-
-From F<d_remainder.U>:
-
-This variable conditionally defines the C<HAS_REMAINDER> symbol, which
-indicates to the C program that the remainder() routine is available.
-
-=item C<d_remquo>
-
-From F<d_remquo.U>:
-
-This variable conditionally defines the C<HAS_REMQUO> symbol, which
-indicates to the C program that the remquo() routine is available.
-
-=item C<d_rename>
-
-From F<d_rename.U>:
-
-This variable conditionally defines the C<HAS_RENAME> symbol, which
-indicates to the C program that the rename() routine is available
-to rename files.
-
-=item C<d_renameat>
-
-From F<d_fsat.U>:
-
-This variable conditionally defines the C<HAS_RENAMEAT> symbol, which
-indicates the C<POSIX> renameat() function is available.
-
-=item C<d_rewinddir>
-
-From F<d_readdir.U>:
-
-This variable conditionally defines C<HAS_REWINDDIR> if rewinddir() is
-available.
-
-=item C<d_rint>
-
-From F<d_rint.U>:
-
-This variable conditionally defines the C<HAS_RINT> symbol, which
-indicates to the C program that the rint() routine is available.
-
-=item C<d_rmdir>
-
-From F<d_rmdir.U>:
-
-This variable conditionally defines C<HAS_RMDIR> if rmdir() is
-available to remove directories.
-
-=item C<d_round>
-
-From F<d_round.U>:
-
-This variable conditionally defines the C<HAS_ROUND> symbol, which
-indicates to the C program that the round() routine is available.
-
-=item C<d_sbrkproto>
-
-From F<d_sbrkproto.U>:
-
-This variable conditionally defines the C<HAS_SBRK_PROTO> symbol,
-which indicates to the C program that the system provides
-a prototype for the sbrk() function. Otherwise, it is
-up to the program to supply one.
-
-=item C<d_scalbn>
-
-From F<d_scalbn.U>:
-
-This variable conditionally defines the C<HAS_SCALBN> symbol, which
-indicates to the C program that the scalbn() routine is available.
-
-=item C<d_scalbnl>
-
-From F<d_scalbnl.U>:
-
-This variable conditionally defines the C<HAS_SCALBNL> symbol, which
-indicates to the C program that the scalbnl() routine is available.
-If ilogbl is also present we can emulate frexpl.
-
-=item C<d_sched_yield>
-
-From F<d_pthread_y.U>:
-
-This variable conditionally defines the C<HAS_SCHED_YIELD>
-symbol if the sched_yield routine is available to yield
-the execution of the current thread.
-
-=item C<d_scm_rights>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the C<HAS_SCM_RIGHTS> symbol,
-which indicates that the C<SCM_RIGHTS> is available. #ifdef is
-not enough because it may be an enum, glibc has been known to do this.
-
-=item C<d_SCNfldbl>
-
-From F<longdblfio.U>:
-
-This variable conditionally defines the PERL_PRIfldbl symbol, which
-indicates that stdio has a symbol to scan long doubles.
-
-=item C<d_seekdir>
-
-From F<d_readdir.U>:
-
-This variable conditionally defines C<HAS_SEEKDIR> if seekdir() is
-available.
-
-=item C<d_select>
-
-From F<d_select.U>:
-
-This variable conditionally defines C<HAS_SELECT> if select() is
-available to select active file descriptors. A <sys/time.h>
-inclusion may be necessary for the timeout field.
-
-=item C<d_sem>
-
-From F<d_sem.U>:
-
-This variable conditionally defines the C<HAS_SEM> symbol, which
-indicates that the entire sem*(2) library is present.
-
-=item C<d_semctl>
-
-From F<d_semctl.U>:
-
-This variable conditionally defines the C<HAS_SEMCTL> symbol, which
-indicates to the C program that the semctl() routine is available.
-
-=item C<d_semctl_semid_ds>
-
-From F<d_union_semun.U>:
-
-This variable conditionally defines C<USE_SEMCTL_SEMID_DS>, which
-indicates that struct semid_ds * is to be used for semctl C<IPC_STAT>.
-
-=item C<d_semctl_semun>
-
-From F<d_union_semun.U>:
-
-This variable conditionally defines C<USE_SEMCTL_SEMUN>, which
-indicates that union semun is to be used for semctl C<IPC_STAT>.
-
-=item C<d_semget>
-
-From F<d_semget.U>:
-
-This variable conditionally defines the C<HAS_SEMGET> symbol, which
-indicates to the C program that the semget() routine is available.
-
-=item C<d_semop>
-
-From F<d_semop.U>:
-
-This variable conditionally defines the C<HAS_SEMOP> symbol, which
-indicates to the C program that the semop() routine is available.
-
-=item C<d_sendmsg>
-
-From F<d_sendmsg.U>:
-
-This variable conditionally defines the C<HAS_SENDMSG> symbol, which
-indicates to the C program that the sendmsg() routine is available.
-
-=item C<d_setegid>
-
-From F<d_setegid.U>:
-
-This variable conditionally defines the C<HAS_SETEGID> symbol, which
-indicates to the C program that the setegid() routine is available
-to change the effective gid of the current program.
-
-=item C<d_seteuid>
-
-From F<d_seteuid.U>:
-
-This variable conditionally defines the C<HAS_SETEUID> symbol, which
-indicates to the C program that the seteuid() routine is available
-to change the effective uid of the current program.
-
-=item C<d_setgrent>
-
-From F<d_setgrent.U>:
-
-This variable conditionally defines the C<HAS_SETGRENT> symbol, which
-indicates to the C program that the setgrent() routine is available
-for initializing sequential access to the group database.
-
-=item C<d_setgrent_r>
-
-From F<d_setgrent_r.U>:
-
-This variable conditionally defines the C<HAS_SETGRENT_R> symbol,
-which indicates to the C program that the setgrent_r()
-routine is available.
-
-=item C<d_setgrps>
-
-From F<d_setgrps.U>:
-
-This variable conditionally defines the C<HAS_SETGROUPS> symbol, which
-indicates to the C program that the setgroups() routine is available
-to set the list of process groups.
-
-=item C<d_sethent>
-
-From F<d_sethent.U>:
-
-This variable conditionally defines C<HAS_SETHOSTENT> if sethostent() is
-available.
-
-=item C<d_sethostent_r>
-
-From F<d_sethostent_r.U>:
-
-This variable conditionally defines the C<HAS_SETHOSTENT_R> symbol,
-which indicates to the C program that the sethostent_r()
-routine is available.
-
-=item C<d_setitimer>
-
-From F<d_setitimer.U>:
-
-This variable conditionally defines the C<HAS_SETITIMER> symbol, which
-indicates to the C program that the setitimer() routine is available.
-
-=item C<d_setlinebuf>
-
-From F<d_setlnbuf.U>:
-
-This variable conditionally defines the C<HAS_SETLINEBUF> symbol, which
-indicates to the C program that the setlinebuf() routine is available
-to change stderr or stdout from block-buffered or unbuffered to a
-line-buffered mode.
-
-=item C<d_setlocale>
-
-From F<d_setlocale.U>:
-
-This variable conditionally defines C<HAS_SETLOCALE> if setlocale() is
-available to handle locale-specific ctype implementations.
-
-=item C<d_setlocale_accepts_any_locale_name>
-
-From F<d_setlocale.U>:
-
-This variable conditionally defines C<SETLOCALE_ACCEPTS_ANY_LOCALE_NAME>
-if setlocale() accepts any locale name.
-
-=item C<d_setlocale_r>
-
-From F<d_setlocale_r.U>:
-
-This variable conditionally defines the C<HAS_SETLOCALE_R> symbol,
-which indicates to the C program that the setlocale_r()
-routine is available.
-
-=item C<d_setnent>
-
-From F<d_setnent.U>:
-
-This variable conditionally defines C<HAS_SETNETENT> if setnetent() is
-available.
-
-=item C<d_setnetent_r>
-
-From F<d_setnetent_r.U>:
-
-This variable conditionally defines the C<HAS_SETNETENT_R> symbol,
-which indicates to the C program that the setnetent_r()
-routine is available.
-
-=item C<d_setpent>
-
-From F<d_setpent.U>:
-
-This variable conditionally defines C<HAS_SETPROTOENT> if setprotoent() is
-available.
-
-=item C<d_setpgid>
-
-From F<d_setpgid.U>:
-
-This variable conditionally defines the C<HAS_SETPGID> symbol if the
-setpgid(pid, gpid) function is available to set process group C<ID>.
-
-=item C<d_setpgrp>
-
-From F<d_setpgrp.U>:
-
-This variable conditionally defines C<HAS_SETPGRP> if setpgrp() is
-available to set the current process group.
-
-=item C<d_setpgrp2>
-
-From F<d_setpgrp2.U>:
-
-This variable conditionally defines the HAS_SETPGRP2 symbol, which
-indicates to the C program that the setpgrp2() (as in F<DG/C<UX>>) routine
-is available to set the current process group.
-
-=item C<d_setprior>
-
-From F<d_setprior.U>:
-
-This variable conditionally defines C<HAS_SETPRIORITY> if setpriority()
-is available to set a process's priority.
-
-=item C<d_setproctitle>
-
-From F<d_setproctitle.U>:
-
-This variable conditionally defines the C<HAS_SETPROCTITLE> symbol,
-which indicates to the C program that the setproctitle() routine
-is available.
-
-=item C<d_setprotoent_r>
-
-From F<d_setprotoent_r.U>:
-
-This variable conditionally defines the C<HAS_SETPROTOENT_R> symbol,
-which indicates to the C program that the setprotoent_r()
-routine is available.
-
-=item C<d_setpwent>
-
-From F<d_setpwent.U>:
-
-This variable conditionally defines the C<HAS_SETPWENT> symbol, which
-indicates to the C program that the setpwent() routine is available
-for initializing sequential access to the passwd database.
-
-=item C<d_setpwent_r>
-
-From F<d_setpwent_r.U>:
-
-This variable conditionally defines the C<HAS_SETPWENT_R> symbol,
-which indicates to the C program that the setpwent_r()
-routine is available.
-
-=item C<d_setregid>
-
-From F<d_setregid.U>:
-
-This variable conditionally defines C<HAS_SETREGID> if setregid() is
-available to change the real and effective gid of the current
-process.
-
-=item C<d_setresgid>
-
-From F<d_setregid.U>:
-
-This variable conditionally defines C<HAS_SETRESGID> if setresgid() is
-available to change the real, effective and saved gid of the current
-process.
-
-=item C<d_setresuid>
-
-From F<d_setreuid.U>:
-
-This variable conditionally defines C<HAS_SETREUID> if setresuid() is
-available to change the real, effective and saved uid of the current
-process.
-
-=item C<d_setreuid>
-
-From F<d_setreuid.U>:
-
-This variable conditionally defines C<HAS_SETREUID> if setreuid() is
-available to change the real and effective uid of the current
-process.
-
-=item C<d_setrgid>
-
-From F<d_setrgid.U>:
-
-This variable conditionally defines the C<HAS_SETRGID> symbol, which
-indicates to the C program that the setrgid() routine is available
-to change the real gid of the current program.
-
-=item C<d_setruid>
-
-From F<d_setruid.U>:
-
-This variable conditionally defines the C<HAS_SETRUID> symbol, which
-indicates to the C program that the setruid() routine is available
-to change the real uid of the current program.
-
-=item C<d_setsent>
-
-From F<d_setsent.U>:
-
-This variable conditionally defines C<HAS_SETSERVENT> if setservent() is
-available.
-
-=item C<d_setservent_r>
-
-From F<d_setservent_r.U>:
-
-This variable conditionally defines the C<HAS_SETSERVENT_R> symbol,
-which indicates to the C program that the setservent_r()
-routine is available.
-
-=item C<d_setsid>
-
-From F<d_setsid.U>:
-
-This variable conditionally defines C<HAS_SETSID> if setsid() is
-available to set the process group C<ID>.
-
-=item C<d_setvbuf>
-
-From F<d_setvbuf.U>:
-
-This variable conditionally defines the C<HAS_SETVBUF> symbol, which
-indicates to the C program that the setvbuf() routine is available
-to change buffering on an open stdio stream.
-
-=item C<d_shm>
-
-From F<d_shm.U>:
-
-This variable conditionally defines the C<HAS_SHM> symbol, which
-indicates that the entire shm*(2) library is present.
-
-=item C<d_shmat>
-
-From F<d_shmat.U>:
-
-This variable conditionally defines the C<HAS_SHMAT> symbol, which
-indicates to the C program that the shmat() routine is available.
-
-=item C<d_shmatprototype>
-
-From F<d_shmat.U>:
-
-This variable conditionally defines the C<HAS_SHMAT_PROTOTYPE>
-symbol, which indicates that F<sys/shm.h> has a prototype for
-shmat.
-
-=item C<d_shmctl>
-
-From F<d_shmctl.U>:
-
-This variable conditionally defines the C<HAS_SHMCTL> symbol, which
-indicates to the C program that the shmctl() routine is available.
-
-=item C<d_shmdt>
-
-From F<d_shmdt.U>:
-
-This variable conditionally defines the C<HAS_SHMDT> symbol, which
-indicates to the C program that the shmdt() routine is available.
-
-=item C<d_shmget>
-
-From F<d_shmget.U>:
-
-This variable conditionally defines the C<HAS_SHMGET> symbol, which
-indicates to the C program that the shmget() routine is available.
-
-=item C<d_sigaction>
-
-From F<d_sigaction.U>:
-
-This variable conditionally defines the C<HAS_SIGACTION> symbol, which
-indicates that the Vr4 sigaction() routine is available.
-
-=item C<d_siginfo_si_addr>
-
-From F<d_siginfo_si.U>:
-
-This variable conditionally defines the C<HAS_SIGINFO_SI_ADDR> symbol,
-which indicates that the siginfo_t struct has the si_addr member.
-
-=item C<d_siginfo_si_band>
-
-From F<d_siginfo_si.U>:
-
-This variable conditionally defines the C<HAS_SIGINFO_SI_BAND> symbol,
-which indicates that the siginfo_t struct has the si_band member.
-
-=item C<d_siginfo_si_errno>
-
-From F<d_siginfo_si.U>:
-
-This variable conditionally defines the C<HAS_SIGINFO_SI_ERRNO> symbol,
-which indicates that the siginfo_t struct has the si_errno member.
-
-=item C<d_siginfo_si_fd>
-
-From F<d_siginfo_si.U>:
-
-This variable conditionally defines the C<HAS_SIGINFO_SI_FD> symbol,
-which indicates that the siginfo_t struct has the si_fd member.
-
-=item C<d_siginfo_si_pid>
-
-From F<d_siginfo_si.U>:
-
-This variable conditionally defines the C<HAS_SIGINFO_SI_PID> symbol,
-which indicates that the siginfo_t struct has the si_pid member.
-
-=item C<d_siginfo_si_status>
-
-From F<d_siginfo_si.U>:
-
-This variable conditionally defines the C<HAS_SIGINFO_SI_STATUS> symbol,
-which indicates that the siginfo_t struct has the si_status member.
-
-=item C<d_siginfo_si_uid>
-
-From F<d_siginfo_si.U>:
-
-This variable conditionally defines the C<HAS_SIGINFO_SI_UID> symbol,
-which indicates that the siginfo_t struct has the si_uid member.
-
-=item C<d_siginfo_si_value>
-
-From F<d_siginfo_si.U>:
-
-This variable conditionally defines the C<HAS_SIGINFO_SI_VALUE> symbol,
-which indicates that the siginfo_t struct has the si_value member.
-
-=item C<d_signbit>
-
-From F<d_signbit.U>:
-
-This variable conditionally defines the C<HAS_SIGNBIT> symbol, which
-indicates to the C program that the signbit() routine is available
-and safe to use with perl's intern C<NV> type.
-
-=item C<d_sigprocmask>
-
-From F<d_sigprocmask.U>:
-
-This variable conditionally defines C<HAS_SIGPROCMASK>
-if sigprocmask() is available to examine or change the signal mask
-of the calling process.
-
-=item C<d_sigsetjmp>
-
-From F<d_sigsetjmp.U>:
-
-This variable conditionally defines the C<HAS_SIGSETJMP> symbol,
-which indicates that the sigsetjmp() routine is available to
-call setjmp() and optionally save the process's signal mask.
-
-=item C<d_sin6_scope_id>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the HAS_SIN6_SCOPE_ID symbol, which
-indicates that a struct sockaddr_in6 structure has the sin6_scope_id
-member.
-
-=item C<d_sitearch>
-
-From F<sitearch.U>:
-
-This variable conditionally defines C<SITEARCH> to hold the pathname
-of architecture-dependent library files for $package. If
-$sitearch is the same as $archlib, then this is set to undef.
-
-=item C<d_snprintf>
-
-From F<d_snprintf.U>:
-
-This variable conditionally defines the C<HAS_SNPRINTF> symbol, which
-indicates to the C program that the snprintf () library function
-is available.
-
-=item C<d_sockaddr_in6>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the HAS_SOCKADDR_IN6 symbol, which
-indicates the availability of a struct sockaddr_in6.
-
-=item C<d_sockaddr_sa_len>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the C<HAS_SOCKADDR_SA_LEN> symbol,
-which indicates that a struct sockaddr structure has the sa_len
-member.
-
-=item C<d_sockatmark>
-
-From F<d_sockatmark.U>:
-
-This variable conditionally defines the C<HAS_SOCKATMARK> symbol, which
-indicates to the C program that the sockatmark() routine is available.
-
-=item C<d_sockatmarkproto>
-
-From F<d_sockatmarkproto.U>:
-
-This variable conditionally defines the C<HAS_SOCKATMARK_PROTO> symbol,
-which indicates to the C program that the system provides
-a prototype for the sockatmark() function. Otherwise, it is
-up to the program to supply one.
-
-=item C<d_socket>
-
-From F<d_socket.U>:
-
-This variable conditionally defines C<HAS_SOCKET>, which indicates
-that the C<BSD> socket interface is supported.
-
-=item C<d_socklen_t>
-
-From F<d_socklen_t.U>:
-
-This symbol will be defined if the C compiler supports socklen_t.
-
-=item C<d_sockpair>
-
-From F<d_socket.U>:
-
-This variable conditionally defines the C<HAS_SOCKETPAIR> symbol, which
-indicates that the C<BSD> socketpair() is supported.
-
-=item C<d_socks5_init>
-
-From F<d_socks5_init.U>:
-
-This variable conditionally defines the HAS_SOCKS5_INIT symbol, which
-indicates to the C program that the socks5_init() routine is available.
-
-=item C<d_sqrtl>
-
-From F<d_sqrtl.U>:
-
-This variable conditionally defines the C<HAS_SQRTL> symbol, which
-indicates to the C program that the sqrtl() routine is available.
-
-=item C<d_srand48_r>
-
-From F<d_srand48_r.U>:
-
-This variable conditionally defines the HAS_SRAND48_R symbol,
-which indicates to the C program that the srand48_r()
-routine is available.
-
-=item C<d_srandom_r>
-
-From F<d_srandom_r.U>:
-
-This variable conditionally defines the C<HAS_SRANDOM_R> symbol,
-which indicates to the C program that the srandom_r()
-routine is available.
-
-=item C<d_sresgproto>
-
-From F<d_sresgproto.U>:
-
-This variable conditionally defines the C<HAS_SETRESGID_PROTO> symbol,
-which indicates to the C program that the system provides
-a prototype for the setresgid() function. Otherwise, it is
-up to the program to supply one.
-
-=item C<d_sresuproto>
-
-From F<d_sresuproto.U>:
-
-This variable conditionally defines the C<HAS_SETRESUID_PROTO> symbol,
-which indicates to the C program that the system provides
-a prototype for the setresuid() function. Otherwise, it is
-up to the program to supply one.
-
-=item C<d_stat>
-
-From F<d_stat.U>:
-
-This variable conditionally defines C<HAS_STAT> if stat() is
-available to get file status.
-
-=item C<d_statblks>
-
-From F<d_statblks.U>:
-
-This variable conditionally defines C<USE_STAT_BLOCKS>
-if this system has a stat structure declaring
-st_blksize and st_blocks.
-
-=item C<d_statfs_f_flags>
-
-From F<d_statfs_f_flags.U>:
-
-This variable conditionally defines the C<HAS_STRUCT_STATFS_F_FLAGS>
-symbol, which indicates to struct statfs from has f_flags member.
-This kind of struct statfs is coming from F<sys/mount.h> (C<BSD>),
-not from F<sys/statfs.h> (C<SYSV>).
-
-=item C<d_statfs_s>
-
-From F<d_statfs_s.U>:
-
-This variable conditionally defines the C<HAS_STRUCT_STATFS> symbol,
-which indicates that the struct statfs is supported.
-
-=item C<d_static_inline>
-
-From F<d_static_inline.U>:
-
-This variable conditionally defines the C<HAS_STATIC_INLINE> symbol,
-which indicates that the C compiler supports C99-style static
-inline. That is, the function can't be called from another
-translation unit.
-
-=item C<d_statvfs>
-
-From F<d_statvfs.U>:
-
-This variable conditionally defines the C<HAS_STATVFS> symbol, which
-indicates to the C program that the statvfs() routine is available.
-
-=item C<d_stdio_cnt_lval>
-
-From F<d_stdstdio.U>:
-
-This variable conditionally defines C<STDIO_CNT_LVALUE> if the
-C<FILE_cnt> macro can be used as an lvalue.
-
-=item C<d_stdio_ptr_lval>
-
-From F<d_stdstdio.U>:
-
-This variable conditionally defines C<STDIO_PTR_LVALUE> if the
-C<FILE_ptr> macro can be used as an lvalue.
-
-=item C<d_stdio_ptr_lval_nochange_cnt>
-
-From F<d_stdstdio.U>:
-
-This symbol is defined if using the C<FILE_ptr> macro as an lvalue
-to increase the pointer by n leaves File_cnt(fp) unchanged.
-
-=item C<d_stdio_ptr_lval_sets_cnt>
-
-From F<d_stdstdio.U>:
-
-This symbol is defined if using the C<FILE_ptr> macro as an lvalue
-to increase the pointer by n has the side effect of decreasing the
-value of File_cnt(fp) by n.
-
-=item C<d_stdio_stream_array>
-
-From F<stdio_streams.U>:
-
-This variable tells whether there is an array holding
-the stdio streams.
-
-=item C<d_stdiobase>
-
-From F<d_stdstdio.U>:
-
-This variable conditionally defines C<USE_STDIO_BASE> if this system
-has a C<FILE> structure declaring a usable _base field (or equivalent)
-in F<stdio.h>.
-
-=item C<d_stdstdio>
-
-From F<d_stdstdio.U>:
-
-This variable conditionally defines C<USE_STDIO_PTR> if this system
-has a C<FILE> structure declaring usable _ptr and _cnt fields (or
-equivalent) in F<stdio.h>.
-
-=item C<d_strcoll>
-
-From F<d_strcoll.U>:
-
-This variable conditionally defines C<HAS_STRCOLL> if strcoll() is
-available to compare strings using collating information.
-
-=item C<d_strerror_l>
-
-From F<d_strerror_l.U>:
-
-This variable conditionally defines the C<HAS_STRERROR_L> symbol, which
-indicates to the C program that the strerror_l() routine is available
-to return the error message for a given errno value in a particular
-locale (identified by a locale_t object).
-
-=item C<d_strerror_r>
-
-From F<d_strerror_r.U>:
-
-This variable conditionally defines the C<HAS_STRERROR_R> symbol,
-which indicates to the C program that the strerror_r()
-routine is available.
-
-=item C<d_strftime>
-
-From F<d_strftime.U>:
-
-This variable conditionally defines the C<HAS_STRFTIME> symbol, which
-indicates to the C program that the strftime() routine is available.
-
-=item C<d_strlcat>
-
-From F<d_strlcat.U>:
-
-This variable conditionally defines the C<HAS_STRLCAT> symbol, which
-indicates to the C program that the strlcat () routine is available.
-
-=item C<d_strlcpy>
-
-From F<d_strlcpy.U>:
-
-This variable conditionally defines the C<HAS_STRLCPY> symbol, which
-indicates to the C program that the strlcpy () routine is available.
-
-=item C<d_strnlen>
-
-From F<d_strnlen.U>:
-
-This variable conditionally defines the C<HAS_STRNLEN> symbol, which
-indicates to the C program that the strnlen () routine is available.
-
-=item C<d_strtod>
-
-From F<d_strtod.U>:
-
-This variable conditionally defines the C<HAS_STRTOD> symbol, which
-indicates to the C program that the strtod() routine is available
-to provide better numeric string conversion than atof().
-
-=item C<d_strtod_l>
-
-From F<d_strtod_l.U>:
-
-This variable conditionally defines the C<HAS_STRTOD_L> symbol, which
-indicates to the C program that the strtod_l() routine is available.
-
-=item C<d_strtol>
-
-From F<d_strtol.U>:
-
-This variable conditionally defines the C<HAS_STRTOL> symbol, which
-indicates to the C program that the strtol() routine is available
-to provide better numeric string conversion than atoi() and friends.
-
-=item C<d_strtold>
-
-From F<d_strtold.U>:
-
-This variable conditionally defines the C<HAS_STRTOLD> symbol, which
-indicates to the C program that the strtold() routine is available.
-
-=item C<d_strtold_l>
-
-From F<d_strtold_l.U>:
-
-This variable conditionally defines the C<HAS_STRTOLD_L> symbol, which
-indicates to the C program that the strtold_l() routine is available.
-
-=item C<d_strtoll>
-
-From F<d_strtoll.U>:
-
-This variable conditionally defines the C<HAS_STRTOLL> symbol, which
-indicates to the C program that the strtoll() routine is available.
-
-=item C<d_strtoq>
-
-From F<d_strtoq.U>:
-
-This variable conditionally defines the C<HAS_STRTOQ> symbol, which
-indicates to the C program that the strtoq() routine is available.
-
-=item C<d_strtoul>
-
-From F<d_strtoul.U>:
-
-This variable conditionally defines the C<HAS_STRTOUL> symbol, which
-indicates to the C program that the strtoul() routine is available
-to provide conversion of strings to unsigned long.
-
-=item C<d_strtoull>
-
-From F<d_strtoull.U>:
-
-This variable conditionally defines the C<HAS_STRTOULL> symbol, which
-indicates to the C program that the strtoull() routine is available.
-
-=item C<d_strtouq>
-
-From F<d_strtouq.U>:
-
-This variable conditionally defines the C<HAS_STRTOUQ> symbol, which
-indicates to the C program that the strtouq() routine is available.
-
-=item C<d_strxfrm>
-
-From F<d_strxfrm.U>:
-
-This variable conditionally defines C<HAS_STRXFRM> if strxfrm() is
-available to transform strings.
-
-=item C<d_suidsafe>
-
-From F<d_dosuid.U>:
-
-This variable conditionally defines C<SETUID_SCRIPTS_ARE_SECURE_NOW>
-if setuid scripts can be secure. This test looks in F</dev/fd/>.
-
-=item C<d_symlink>
-
-From F<d_symlink.U>:
-
-This variable conditionally defines the C<HAS_SYMLINK> symbol, which
-indicates to the C program that the symlink() routine is available
-to create symbolic links.
-
-=item C<d_syscall>
-
-From F<d_syscall.U>:
-
-This variable conditionally defines C<HAS_SYSCALL> if syscall() is
-available call arbitrary system calls.
-
-=item C<d_syscallproto>
-
-From F<d_syscallproto.U>:
-
-This variable conditionally defines the C<HAS_SYSCALL_PROTO> symbol,
-which indicates to the C program that the system provides
-a prototype for the syscall() function. Otherwise, it is
-up to the program to supply one.
-
-=item C<d_sysconf>
-
-From F<d_sysconf.U>:
-
-This variable conditionally defines the C<HAS_SYSCONF> symbol, which
-indicates to the C program that the sysconf() routine is available
-to determine system related limits and options.
-
-=item C<d_sysernlst>
-
-From F<d_strerror.U>:
-
-This variable conditionally defines C<HAS_SYS_ERRNOLIST> if sys_errnolist[]
-is available to translate error numbers to the symbolic name.
-
-=item C<d_syserrlst>
-
-From F<d_strerror.U>:
-
-This variable conditionally defines C<HAS_SYS_ERRLIST> if sys_errlist[] is
-available to translate error numbers to strings.
-
-=item C<d_system>
-
-From F<d_system.U>:
-
-This variable conditionally defines C<HAS_SYSTEM> if system() is
-available to issue a shell command.
-
-=item C<d_tcgetpgrp>
-
-From F<d_tcgtpgrp.U>:
-
-This variable conditionally defines the C<HAS_TCGETPGRP> symbol, which
-indicates to the C program that the tcgetpgrp() routine is available.
-to get foreground process group C<ID>.
-
-=item C<d_tcsetpgrp>
-
-From F<d_tcstpgrp.U>:
-
-This variable conditionally defines the C<HAS_TCSETPGRP> symbol, which
-indicates to the C program that the tcsetpgrp() routine is available
-to set foreground process group C<ID>.
-
-=item C<d_telldir>
-
-From F<d_readdir.U>:
-
-This variable conditionally defines C<HAS_TELLDIR> if telldir() is
-available.
-
-=item C<d_telldirproto>
-
-From F<d_telldirproto.U>:
-
-This variable conditionally defines the C<HAS_TELLDIR_PROTO> symbol,
-which indicates to the C program that the system provides
-a prototype for the telldir() function. Otherwise, it is
-up to the program to supply one.
-
-=item C<d_tgamma>
-
-From F<d_tgamma.U>:
-
-This variable conditionally defines the C<HAS_TGAMMA> symbol, which
-indicates to the C program that the tgamma() routine is available
-for the gamma function. See also d_lgamma.
-
-=item C<d_thread_safe_nl_langinfo_l>
-
-From F<d_nl_langinfo_l.U>:
-
-This variable contains the eventual value of the
-C<HAS_THREAD_SAFE_NL_LANGINFO_L> symbol, which indicates if the
-nl_langinfo_l() function exists and is thread-safe.
-
-=item C<d_time>
-
-From F<d_time.U>:
-
-This variable conditionally defines the C<HAS_TIME> symbol, which indicates
-that the time() routine exists. The time() routine is normally
-provided on C<UNIX> systems.
-
-=item C<d_timegm>
-
-From F<d_timegm.U>:
-
-This variable conditionally defines the C<HAS_TIMEGM> symbol, which
-indicates to the C program that the timegm () routine is available.
-
-=item C<d_times>
-
-From F<d_times.U>:
-
-This variable conditionally defines the C<HAS_TIMES> symbol, which indicates
-that the times() routine exists. The times() routine is normally
-provided on C<UNIX> systems. You may have to include <sys/times.h>.
-
-=item C<d_tm_tm_gmtoff>
-
-From F<i_time.U>:
-
-This variable conditionally defines C<HAS_TM_TM_GMTOFF>, which indicates
-to the C program that the struct tm has the tm_gmtoff field.
-
-=item C<d_tm_tm_zone>
-
-From F<i_time.U>:
-
-This variable conditionally defines C<HAS_TM_TM_ZONE>, which indicates
-to the C program that the struct tm has the tm_zone field.
-
-=item C<d_tmpnam_r>
-
-From F<d_tmpnam_r.U>:
-
-This variable conditionally defines the C<HAS_TMPNAM_R> symbol,
-which indicates to the C program that the tmpnam_r()
-routine is available.
-
-=item C<d_towlower>
-
-From F<d_towlower.U>:
-
-This variable conditionally defines the C<HAS_TOWLOWER> symbol, which
-indicates to the C program that the towlower() routine is available.
-
-=item C<d_towupper>
-
-From F<d_towupper.U>:
-
-This variable conditionally defines the C<HAS_TOWUPPER> symbol, which
-indicates to the C program that the towupper() routine is available.
-
-=item C<d_trunc>
-
-From F<d_trunc.U>:
-
-This variable conditionally defines the C<HAS_TRUNC> symbol, which
-indicates to the C program that the trunc() routine is available
-to round doubles towards zero.
-
-=item C<d_truncate>
-
-From F<d_truncate.U>:
-
-This variable conditionally defines C<HAS_TRUNCATE> if truncate() is
-available to truncate files.
-
-=item C<d_truncl>
-
-From F<d_truncl.U>:
-
-This variable conditionally defines the C<HAS_TRUNCL> symbol, which
-indicates to the C program that the truncl() routine is available
-to round long doubles towards zero. If copysignl is also present,
-we can emulate modfl.
-
-=item C<d_ttyname_r>
-
-From F<d_ttyname_r.U>:
-
-This variable conditionally defines the C<HAS_TTYNAME_R> symbol,
-which indicates to the C program that the ttyname_r()
-routine is available.
-
-=item C<d_tzname>
-
-From F<d_tzname.U>:
-
-This variable conditionally defines C<HAS_TZNAME> if tzname[] is
-available to access timezone names.
-
-=item C<d_u32align>
-
-From F<d_u32align.U>:
-
-This variable tells whether you must access character data
-through U32-aligned pointers.
-
-=item C<d_ualarm>
-
-From F<d_ualarm.U>:
-
-This variable conditionally defines the C<HAS_UALARM> symbol, which
-indicates to the C program that the ualarm() routine is available.
-
-=item C<d_umask>
-
-From F<d_umask.U>:
-
-This variable conditionally defines the C<HAS_UMASK> symbol, which
-indicates to the C program that the umask() routine is available.
-to set and get the value of the file creation mask.
-
-=item C<d_uname>
-
-From F<d_gethname.U>:
-
-This variable conditionally defines the C<HAS_UNAME> symbol, which
-indicates to the C program that the uname() routine may be
-used to derive the host name.
-
-=item C<d_union_semun>
-
-From F<d_union_semun.U>:
-
-This variable conditionally defines C<HAS_UNION_SEMUN> if the
-union semun is defined by including <sys/sem.h>.
-
-=item C<d_unlinkat>
-
-From F<d_fsat.U>:
-
-This variable conditionally defines the C<HAS_UNLINKAT> symbol, which
-indicates the C<POSIX> unlinkat() function isavailable.
-
-=item C<d_unordered>
-
-From F<d_unordered.U>:
-
-This variable conditionally defines the C<HAS_UNORDERED> symbol, which
-indicates to the C program that the unordered() routine is available.
-
-=item C<d_unsetenv>
-
-From F<d_unsetenv.U>:
-
-This variable conditionally defines the C<HAS_UNSETENV> symbol, which
-indicates to the C program that the unsetenv () routine is available.
-
-=item C<d_uselocale>
-
-From F<d_newlocale.U>:
-
-This variable conditionally defines the C<HAS_USELOCALE> symbol, which
-indicates to the C program that the uselocale() routine is available
-to set the current locale for the calling thread.
-
-=item C<d_usleep>
-
-From F<d_usleep.U>:
-
-This variable conditionally defines C<HAS_USLEEP> if usleep() is
-available to do high granularity sleeps.
-
-=item C<d_usleepproto>
-
-From F<d_usleepproto.U>:
-
-This variable conditionally defines the C<HAS_USLEEP_PROTO> symbol,
-which indicates to the C program that the system provides
-a prototype for the usleep() function. Otherwise, it is
-up to the program to supply one.
-
-=item C<d_ustat>
-
-From F<d_ustat.U>:
-
-This variable conditionally defines C<HAS_USTAT> if ustat() is
-available to query file system statistics by dev_t.
-
-=item C<d_vendorarch>
-
-From F<vendorarch.U>:
-
-This variable conditionally defined C<PERL_VENDORARCH>.
-
-=item C<d_vendorbin>
-
-From F<vendorbin.U>:
-
-This variable conditionally defines C<PERL_VENDORBIN>.
-
-=item C<d_vendorlib>
-
-From F<vendorlib.U>:
-
-This variable conditionally defines C<PERL_VENDORLIB>.
-
-=item C<d_vendorscript>
-
-From F<vendorscript.U>:
-
-This variable conditionally defines C<PERL_VENDORSCRIPT>.
-
-=item C<d_vfork>
-
-From F<d_vfork.U>:
-
-This variable conditionally defines the C<HAS_VFORK> symbol, which
-indicates the vfork() routine is available.
-
-=item C<d_void_closedir>
-
-From F<d_closedir.U>:
-
-This variable conditionally defines C<VOID_CLOSEDIR> if closedir()
-does not return a value.
-
-=item C<d_voidsig>
-
-From F<d_voidsig.U>:
-
-This variable conditionally defines C<VOIDSIG> if this system
-declares "void (*signal(...))()" in F<signal.h>. The old way was to
-declare it as "int (*signal(...))()".
-
-=item C<d_voidtty>
-
-From F<i_sysioctl.U>:
-
-This variable conditionally defines C<USE_IOCNOTTY> to indicate that the
-ioctl() call with C<TIOCNOTTY> should be used to void tty association.
-Otherwise (on C<USG> probably), it is enough to close the standard file
-descriptors and do a setpgrp().
-
-=item C<d_vsnprintf>
-
-From F<d_snprintf.U>:
-
-This variable conditionally defines the C<HAS_VSNPRINTF> symbol, which
-indicates to the C program that the vsnprintf () library function
-is available.
-
-=item C<d_wait4>
-
-From F<d_wait4.U>:
-
-This variable conditionally defines the HAS_WAIT4 symbol, which
-indicates the wait4() routine is available.
-
-=item C<d_waitpid>
-
-From F<d_waitpid.U>:
-
-This variable conditionally defines C<HAS_WAITPID> if waitpid() is
-available to wait for child process.
-
-=item C<d_wcscmp>
-
-From F<d_wcscmp.U>:
-
-This variable conditionally defines the C<HAS_WCSCMP> symbol if the
-wcscmp() routine is available and can be used to compare wide
-character strings.
-
-=item C<d_wcstombs>
-
-From F<d_wcstombs.U>:
-
-This variable conditionally defines the C<HAS_WCSTOMBS> symbol, which
-indicates to the C program that the wcstombs() routine is available
-to convert wide character strings to multibyte strings.
-
-=item C<d_wcsxfrm>
-
-From F<d_wcsxfrm.U>:
-
-This variable conditionally defines the C<HAS_WCSXFRM> symbol if the
-wcsxfrm() routine is available and can be used to compare wide
-character strings.
-
-=item C<d_wctomb>
-
-From F<d_wctomb.U>:
-
-This variable conditionally defines the C<HAS_WCTOMB> symbol, which
-indicates to the C program that the wctomb() routine is available
-to convert a wide character to a multibyte.
-
-=item C<d_writev>
-
-From F<d_writev.U>:
-
-This variable conditionally defines the C<HAS_WRITEV> symbol, which
-indicates to the C program that the writev() routine is available.
-
-=item C<d_xenix>
-
-From F<Guess.U>:
-
-This variable conditionally defines the symbol C<XENIX>, which alerts
-the C program that it runs under Xenix.
-
-=item C<date>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the date program. After Configure runs,
-the value is reset to a plain C<date> and is not useful.
-
-=item C<db_hashtype>
-
-From F<i_db.U>:
-
-This variable contains the type of the hash structure element
-in the <db.h> header file. In older versions of C<DB>, it was
-int, while in newer ones it is u_int32_t.
-
-=item C<db_prefixtype>
-
-From F<i_db.U>:
-
-This variable contains the type of the prefix structure element
-in the <db.h> header file. In older versions of C<DB>, it was
-int, while in newer ones it is size_t.
-
-=item C<db_version_major>
-
-From F<i_db.U>:
-
-This variable contains the major version number of
-Berkeley C<DB> found in the <db.h> header file.
-
-=item C<db_version_minor>
-
-From F<i_db.U>:
-
-This variable contains the minor version number of
-Berkeley C<DB> found in the <db.h> header file.
-For C<DB> version 1 this is always 0.
-
-=item C<db_version_patch>
-
-From F<i_db.U>:
-
-This variable contains the patch version number of
-Berkeley C<DB> found in the <db.h> header file.
-For C<DB> version 1 this is always 0.
-
-=item C<default_inc_excludes_dot>
-
-From F<defaultincdot.U>:
-
-When defined, remove the legacy F<.> from @C<INC>
-
-=item C<direntrytype>
-
-From F<i_dirent.U>:
-
-This symbol is set to C<struct direct> or C<struct dirent> depending on
-whether dirent is available or not. You should use this pseudo type to
-portably declare your directory entries.
-
-=item C<dlext>
-
-From F<dlext.U>:
-
-This variable contains the extension that is to be used for the
-dynamically loaded modules that perl generates.
-
-=item C<dlsrc>
-
-From F<dlsrc.U>:
-
-This variable contains the name of the dynamic loading file that
-will be used with the package.
-
-=item C<doubleinfbytes>
-
-From F<infnan.U>:
-
-This variable contains comma-separated list of hexadecimal bytes
-for the double precision infinity.
-
-=item C<doublekind>
-
-From F<longdblfio.U>:
-
-This variable, if defined, encodes the type of a double:
-1 = C<IEEE> 754 32-bit little endian,
-2 = C<IEEE> 754 32-bit big endian,
-3 = C<IEEE> 754 64-bit little endian,
-4 = C<IEEE> 754 64-bit big endian,
-5 = C<IEEE> 754 128-bit little endian,
-6 = C<IEEE> 754 128-bit big endian,
-7 = C<IEEE> 754 64-bit mixed endian le-be,
-8 = C<IEEE> 754 64-bit mixed endian be-le,
-9 = C<VAX> 32bit little endian F float format
-10 = C<VAX> 64bit little endian D float format
-11 = C<VAX> 64bit little endian G float format
-12 = C<IBM> 32bit format
-13 = C<IBM> 64bit format
-14 = Cray 64bit format
--1 = unknown format.
-
-=item C<doublemantbits>
-
-From F<mantbits.U>:
-
-This symbol, if defined, tells how many mantissa bits
-there are in double precision floating point format.
-Note that this is usually C<DBL_MANT_DIG> minus one, since
-with the standard C<IEEE> 754 formats C<DBL_MANT_DIG> includes
-the implicit bit which doesn't really exist.
-
-=item C<doublenanbytes>
-
-From F<infnan.U>:
-
-This variable contains comma-separated list of hexadecimal bytes
-for the double precision not-a-number.
-
-=item C<doublesize>
-
-From F<doublesize.U>:
-
-This variable contains the value of the C<DOUBLESIZE> symbol, which
-indicates to the C program how many bytes there are in a double.
-
-=item C<drand01>
-
-From F<randfunc.U>:
-
-Indicates the macro to be used to generate normalized
-random numbers. Uses randfunc, often divided by
-(double) (((unsigned long) 1 << randbits)) in order to
-normalize the result.
-In C programs, the macro C<Drand01> is mapped to drand01.
-
-=item C<drand48_r_proto>
-
-From F<d_drand48_r.U>:
-
-This variable encodes the prototype of drand48_r.
-It is zero if d_drand48_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_drand48_r
-is defined.
-
-=item C<dtrace>
-
-From F<usedtrace.U>:
-
-This variable holds the location of the dtrace executable.
-
-=item C<dtraceobject>
-
-From F<dtraceobject.U>:
-
-Whether we need to build an object file with the dtrace tool.
-
-=item C<dtracexnolibs>
-
-From F<dtraceobject.U>:
-
-Whether dtrace accepts -xnolibs. If available we call dtrace -h
-and dtrace -G with -xnolibs to allow dtrace to run in a jail on
-FreeBSD.
-
-=item C<dynamic_ext>
-
-From F<Extensions.U>:
-
-This variable holds a list of C<XS> extension files we want to
-link dynamically into the package. It is used by Makefile.
-
-=back
-
-=head2 e
-
-=over 4
-
-=item C<eagain>
-
-From F<nblock_io.U>:
-
-This variable bears the symbolic errno code set by read() when no
-data is present on the file and non-blocking I/O was enabled (otherwise,
-read() blocks naturally).
-
-=item C<ebcdic>
-
-From F<ebcdic.U>:
-
-This variable conditionally defines C<EBCDIC> if this
-system uses C<EBCDIC> encoding.
-
-=item C<echo>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the echo program. After Configure runs,
-the value is reset to a plain C<echo> and is not useful.
-
-=item C<egrep>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the egrep program. After Configure runs,
-the value is reset to a plain C<egrep> and is not useful.
-
-=item C<emacs>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<endgrent_r_proto>
-
-From F<d_endgrent_r.U>:
-
-This variable encodes the prototype of endgrent_r.
-It is zero if d_endgrent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endgrent_r
-is defined.
-
-=item C<endhostent_r_proto>
-
-From F<d_endhostent_r.U>:
-
-This variable encodes the prototype of endhostent_r.
-It is zero if d_endhostent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endhostent_r
-is defined.
-
-=item C<endnetent_r_proto>
-
-From F<d_endnetent_r.U>:
-
-This variable encodes the prototype of endnetent_r.
-It is zero if d_endnetent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endnetent_r
-is defined.
-
-=item C<endprotoent_r_proto>
-
-From F<d_endprotoent_r.U>:
-
-This variable encodes the prototype of endprotoent_r.
-It is zero if d_endprotoent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endprotoent_r
-is defined.
-
-=item C<endpwent_r_proto>
-
-From F<d_endpwent_r.U>:
-
-This variable encodes the prototype of endpwent_r.
-It is zero if d_endpwent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endpwent_r
-is defined.
-
-=item C<endservent_r_proto>
-
-From F<d_endservent_r.U>:
-
-This variable encodes the prototype of endservent_r.
-It is zero if d_endservent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endservent_r
-is defined.
-
-=item C<eunicefix>
-
-From F<Init.U>:
-
-When running under Eunice this variable contains a command which will
-convert a shell script to the proper form of text file for it to be
-executable by the shell. On other systems it is a no-op.
-
-=item C<exe_ext>
-
-From F<Unix.U>:
-
-This is an old synonym for _exe.
-
-=item C<expr>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the expr program. After Configure runs,
-the value is reset to a plain C<expr> and is not useful.
-
-=item C<extensions>
-
-From F<Extensions.U>:
-
-This variable holds a list of all extension files (both C<XS> and
-non-xs) installed with the package. It is propagated to F<Config.pm>
-and is typically used to test whether a particular extension
-is available.
-
-=item C<extern_C>
-
-From F<Csym.U>:
-
-C<ANSI> C requires C<extern> where C++ requires 'extern C<C>'. This
-variable can be used in Configure to do the right thing.
-
-=item C<extras>
-
-From F<Extras.U>:
-
-This variable holds a list of extra modules to install.
-
-=back
-
-=head2 f
-
-=over 4
-
-=item C<fflushall>
-
-From F<fflushall.U>:
-
-This symbol, if defined, tells that to flush
-all pending stdio output one must loop through all
-the stdio file handles stored in an array and fflush them.
-Note that if fflushNULL is defined, fflushall will not
-even be probed for and will be left undefined.
-
-=item C<fflushNULL>
-
-From F<fflushall.U>:
-
-This symbol, if defined, tells that fflush(C<NULL>) correctly
-flushes all pending stdio output without side effects. In
-particular, on some platforms calling fflush(C<NULL>) *still*
-corrupts C<STDIN> if it is a pipe.
-
-=item C<find>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<firstmakefile>
-
-From F<Unix.U>:
-
-This variable defines the first file searched by make. On unix,
-it is makefile (then Makefile). On case-insensitive systems,
-it might be something else. This is only used to deal with
-convoluted make depend tricks.
-
-=item C<flex>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<fpossize>
-
-From F<fpossize.U>:
-
-This variable contains the size of a fpostype in bytes.
-
-=item C<fpostype>
-
-From F<fpostype.U>:
-
-This variable defines Fpos_t to be something like fpos_t, long,
-uint, or whatever type is used to declare file positions in libc.
-
-=item C<freetype>
-
-From F<mallocsrc.U>:
-
-This variable contains the return type of free(). It is usually
-void, but occasionally int.
-
-=item C<from>
-
-From F<Cross.U>:
-
-This variable contains the command used by Configure
-to copy files from the target host. Useful and available
-only during Perl build.
-The string C<:> if not cross-compiling.
-
-=item C<full_ar>
-
-From F<Loc_ar.U>:
-
-This variable contains the full pathname to C<ar>, whether or
-not the user has specified C<portability>. This is only used
-in the F<Makefile.SH>.
-
-=item C<full_csh>
-
-From F<d_csh.U>:
-
-This variable contains the full pathname to C<csh>, whether or
-not the user has specified C<portability>. This is only used
-in the compiled C program, and we assume that all systems which
-can share this executable will have the same full pathname to
-F<csh.>
-
-=item C<full_sed>
-
-From F<Loc_sed.U>:
-
-This variable contains the full pathname to C<sed>, whether or
-not the user has specified C<portability>. This is only used
-in the compiled C program, and we assume that all systems which
-can share this executable will have the same full pathname to
-F<sed.>
-
-=back
-
-=head2 g
-
-=over 4
-
-=item C<gccansipedantic>
-
-From F<gccvers.U>:
-
-If C<GNU> cc (gcc) is used, this variable will enable (if set) the
--ansi and -pedantic ccflags for building core files (through
-cflags script). (See F<Porting/pumpkin.pod> for full description).
-
-=item C<gccosandvers>
-
-From F<gccvers.U>:
-
-If C<GNU> cc (gcc) is used, this variable holds the operating system
-and version used to compile gcc. It is set to '' if not gcc,
-or if nothing useful can be parsed as the os version.
-
-=item C<gccversion>
-
-From F<gccvers.U>:
-
-If C<GNU> cc (gcc) is used, this variable holds C<1> or C<2> to
-indicate whether the compiler is version 1 or 2. This is used in
-setting some of the default cflags. It is set to '' if not gcc.
-
-=item C<getgrent_r_proto>
-
-From F<d_getgrent_r.U>:
-
-This variable encodes the prototype of getgrent_r.
-It is zero if d_getgrent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getgrent_r
-is defined.
-
-=item C<getgrgid_r_proto>
-
-From F<d_getgrgid_r.U>:
-
-This variable encodes the prototype of getgrgid_r.
-It is zero if d_getgrgid_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getgrgid_r
-is defined.
-
-=item C<getgrnam_r_proto>
-
-From F<d_getgrnam_r.U>:
-
-This variable encodes the prototype of getgrnam_r.
-It is zero if d_getgrnam_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getgrnam_r
-is defined.
-
-=item C<gethostbyaddr_r_proto>
-
-From F<d_gethostbyaddr_r.U>:
-
-This variable encodes the prototype of gethostbyaddr_r.
-It is zero if d_gethostbyaddr_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_gethostbyaddr_r
-is defined.
-
-=item C<gethostbyname_r_proto>
-
-From F<d_gethostbyname_r.U>:
-
-This variable encodes the prototype of gethostbyname_r.
-It is zero if d_gethostbyname_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_gethostbyname_r
-is defined.
-
-=item C<gethostent_r_proto>
-
-From F<d_gethostent_r.U>:
-
-This variable encodes the prototype of gethostent_r.
-It is zero if d_gethostent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_gethostent_r
-is defined.
-
-=item C<getlogin_r_proto>
-
-From F<d_getlogin_r.U>:
-
-This variable encodes the prototype of getlogin_r.
-It is zero if d_getlogin_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getlogin_r
-is defined.
-
-=item C<getnetbyaddr_r_proto>
-
-From F<d_getnetbyaddr_r.U>:
-
-This variable encodes the prototype of getnetbyaddr_r.
-It is zero if d_getnetbyaddr_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getnetbyaddr_r
-is defined.
-
-=item C<getnetbyname_r_proto>
-
-From F<d_getnetbyname_r.U>:
-
-This variable encodes the prototype of getnetbyname_r.
-It is zero if d_getnetbyname_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getnetbyname_r
-is defined.
-
-=item C<getnetent_r_proto>
-
-From F<d_getnetent_r.U>:
-
-This variable encodes the prototype of getnetent_r.
-It is zero if d_getnetent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getnetent_r
-is defined.
-
-=item C<getprotobyname_r_proto>
-
-From F<d_getprotobyname_r.U>:
-
-This variable encodes the prototype of getprotobyname_r.
-It is zero if d_getprotobyname_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getprotobyname_r
-is defined.
-
-=item C<getprotobynumber_r_proto>
-
-From F<d_getprotobynumber_r.U>:
-
-This variable encodes the prototype of getprotobynumber_r.
-It is zero if d_getprotobynumber_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getprotobynumber_r
-is defined.
-
-=item C<getprotoent_r_proto>
-
-From F<d_getprotoent_r.U>:
-
-This variable encodes the prototype of getprotoent_r.
-It is zero if d_getprotoent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getprotoent_r
-is defined.
-
-=item C<getpwent_r_proto>
-
-From F<d_getpwent_r.U>:
-
-This variable encodes the prototype of getpwent_r.
-It is zero if d_getpwent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getpwent_r
-is defined.
-
-=item C<getpwnam_r_proto>
-
-From F<d_getpwnam_r.U>:
-
-This variable encodes the prototype of getpwnam_r.
-It is zero if d_getpwnam_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getpwnam_r
-is defined.
-
-=item C<getpwuid_r_proto>
-
-From F<d_getpwuid_r.U>:
-
-This variable encodes the prototype of getpwuid_r.
-It is zero if d_getpwuid_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getpwuid_r
-is defined.
-
-=item C<getservbyname_r_proto>
-
-From F<d_getservbyname_r.U>:
-
-This variable encodes the prototype of getservbyname_r.
-It is zero if d_getservbyname_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getservbyname_r
-is defined.
-
-=item C<getservbyport_r_proto>
-
-From F<d_getservbyport_r.U>:
-
-This variable encodes the prototype of getservbyport_r.
-It is zero if d_getservbyport_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getservbyport_r
-is defined.
-
-=item C<getservent_r_proto>
-
-From F<d_getservent_r.U>:
-
-This variable encodes the prototype of getservent_r.
-It is zero if d_getservent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getservent_r
-is defined.
-
-=item C<getspnam_r_proto>
-
-From F<d_getspnam_r.U>:
-
-This variable encodes the prototype of getspnam_r.
-It is zero if d_getspnam_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getspnam_r
-is defined.
-
-=item C<gidformat>
-
-From F<gidf.U>:
-
-This variable contains the format string used for printing a Gid_t.
-
-=item C<gidsign>
-
-From F<gidsign.U>:
-
-This variable contains the signedness of a gidtype.
-1 for unsigned, -1 for signed.
-
-=item C<gidsize>
-
-From F<gidsize.U>:
-
-This variable contains the size of a gidtype in bytes.
-
-=item C<gidtype>
-
-From F<gidtype.U>:
-
-This variable defines Gid_t to be something like gid_t, int,
-ushort, or whatever type is used to declare the return type
-of getgid(). Typically, it is the type of group ids in the kernel.
-
-=item C<glibpth>
-
-From F<libpth.U>:
-
-This variable holds the general path (space-separated) used to
-find libraries. It may contain directories that do not exist on
-this platform, libpth is the cleaned-up version.
-
-=item C<gmake>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the gmake program. After Configure runs,
-the value is reset to a plain C<gmake> and is not useful.
-
-=item C<gmtime_r_proto>
-
-From F<d_gmtime_r.U>:
-
-This variable encodes the prototype of gmtime_r.
-It is zero if d_gmtime_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_gmtime_r
-is defined.
-
-=item C<gnulibc_version>
-
-From F<d_gnulibc.U>:
-
-This variable contains the version number of the C<GNU> C library.
-It is usually something like F<2.2.5>. It is a plain '' if this
-is not the C<GNU> C library, or if the version is unknown.
-
-=item C<grep>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the grep program. After Configure runs,
-the value is reset to a plain C<grep> and is not useful.
-
-=item C<groupcat>
-
-From F<nis.U>:
-
-This variable contains a command that produces the text of the
-F</etc/group> file. This is normally "cat F</etc/group>", but can be
-"ypcat group" when C<NIS> is used.
-On some systems, such as os390, there may be no equivalent
-command, in which case this variable is unset.
-
-=item C<groupstype>
-
-From F<groupstype.U>:
-
-This variable defines Groups_t to be something like gid_t, int,
-ushort, or whatever type is used for the second argument to
-getgroups() and setgroups(). Usually, this is the same as
-gidtype (gid_t), but sometimes it isn't.
-
-=item C<gzip>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the gzip program. After Configure runs,
-the value is reset to a plain C<gzip> and is not useful.
-
-=back
-
-=head2 h
-
-=over 4
-
-=item C<h_fcntl>
-
-From F<h_fcntl.U>:
-
-This is variable gets set in various places to tell i_fcntl that
-<fcntl.h> should be included.
-
-=item C<h_sysfile>
-
-From F<h_sysfile.U>:
-
-This is variable gets set in various places to tell i_sys_file that
-<sys/file.h> should be included.
-
-=item C<hint>
-
-From F<Oldconfig.U>:
-
-Gives the type of hints used for previous answers. May be one of
-C<default>, C<recommended> or C<previous>.
-
-=item C<hostcat>
-
-From F<nis.U>:
-
-This variable contains a command that produces the text of the
-F</etc/hosts> file. This is normally "cat F</etc/hosts>", but can be
-"ypcat hosts" when C<NIS> is used.
-On some systems, such as os390, there may be no equivalent
-command, in which case this variable is unset.
-
-=item C<hostgenerate>
-
-From F<Cross.U>:
-
-This variable contains the path to a generate_uudmap binary that
-can be run on the host C<OS> when cross-compiling. Useful and
-available only during Perl build.
-Empty string '' if not cross-compiling.
-
-=item C<hostosname>
-
-From F<Cross.U>:
-
-This variable contains the original value of C<$^O> for hostperl
-when cross-compiling. This is useful to pick the proper tools
-when running build code in the host.
-Empty string '' if not cross-compiling.
-
-=item C<hostperl>
-
-From F<Cross.U>:
-
-This variable contains the path to a miniperl binary that can be
-run on the host C<OS> when cross-compiling. Useful and available only
-during Perl build.
-Empty string '' if not cross-compiling.
-
-=item C<html1dir>
-
-From F<html1dir.U>:
-
-This variable contains the name of the directory in which html
-source pages are to be put. This directory is for pages
-that describe whole programs, not libraries or modules. It
-is intended to correspond roughly to section 1 of the Unix
-manuals.
-
-=item C<html1direxp>
-
-From F<html1dir.U>:
-
-This variable is the same as the html1dir variable, but is filename
-expanded at configuration time, for convenient use in makefiles.
-
-=item C<html3dir>
-
-From F<html3dir.U>:
-
-This variable contains the name of the directory in which html
-source pages are to be put. This directory is for pages
-that describe libraries or modules. It is intended to
-correspond roughly to section 3 of the Unix manuals.
-
-=item C<html3direxp>
-
-From F<html3dir.U>:
-
-This variable is the same as the html3dir variable, but is filename
-expanded at configuration time, for convenient use in makefiles.
-
-=back
-
-=head2 i
-
-=over 4
-
-=item C<i16size>
-
-From F<perlxv.U>:
-
-This variable is the size of an I16 in bytes.
-
-=item C<i16type>
-
-From F<perlxv.U>:
-
-This variable contains the C type used for Perl's I16.
-
-=item C<i32size>
-
-From F<perlxv.U>:
-
-This variable is the size of an I32 in bytes.
-
-=item C<i32type>
-
-From F<perlxv.U>:
-
-This variable contains the C type used for Perl's I32.
-
-=item C<i64size>
-
-From F<perlxv.U>:
-
-This variable is the size of an I64 in bytes.
-
-=item C<i64type>
-
-From F<perlxv.U>:
-
-This variable contains the C type used for Perl's I64.
-
-=item C<i8size>
-
-From F<perlxv.U>:
-
-This variable is the size of an I8 in bytes.
-
-=item C<i8type>
-
-From F<perlxv.U>:
-
-This variable contains the C type used for Perl's I8.
-
-=item C<i_arpainet>
-
-From F<i_arpainet.U>:
-
-This variable conditionally defines the C<I_ARPA_INET> symbol,
-and indicates whether a C program should include <arpa/inet.h>.
-
-=item C<i_bfd>
-
-From F<i_bfd.U>:
-
-This variable conditionally defines the C<I_BFD> symbol, and
-indicates whether a C program can include <bfd.h>.
-
-=item C<i_bsdioctl>
-
-From F<i_sysioctl.U>:
-
-This variable conditionally defines the C<I_SYS_BSDIOCTL> symbol, which
-indicates to the C program that <sys/bsdioctl.h> exists and should
-be included.
-
-=item C<i_crypt>
-
-From F<i_crypt.U>:
-
-This variable conditionally defines the C<I_CRYPT> symbol, and indicates
-whether a C program should include <crypt.h>.
-
-=item C<i_db>
-
-From F<i_db.U>:
-
-This variable conditionally defines the C<I_DB> symbol, and indicates
-whether a C program may include Berkeley's C<DB> include file <db.h>.
-
-=item C<i_dbm>
-
-From F<i_dbm.U>:
-
-This variable conditionally defines the C<I_DBM> symbol, which
-indicates to the C program that <dbm.h> exists and should
-be included.
-
-=item C<i_dirent>
-
-From F<i_dirent.U>:
-
-This variable conditionally defines C<I_DIRENT>, which indicates
-to the C program that it should include <dirent.h>.
-
-=item C<i_dlfcn>
-
-From F<i_dlfcn.U>:
-
-This variable conditionally defines the C<I_DLFCN> symbol, which
-indicates to the C program that <dlfcn.h> exists and should
-be included.
-
-=item C<i_execinfo>
-
-From F<i_execinfo.U>:
-
-This variable conditionally defines the C<I_EXECINFO> symbol, and indicates
-whether a C program may include <execinfo.h>, for backtrace() support.
-
-=item C<i_fcntl>
-
-From F<i_fcntl.U>:
-
-This variable controls the value of C<I_FCNTL> (which tells
-the C program to include <fcntl.h>).
-
-=item C<i_fenv>
-
-From F<i_fenv.U>:
-
-This variable conditionally defines the C<I_FENV> symbol, which
-indicates to the C program that <fenv.h> exists and should
-be included.
-
-=item C<i_fp>
-
-From F<i_fp.U>:
-
-This variable conditionally defines the C<I_FP> symbol, and indicates
-whether a C program should include <fp.h>.
-
-=item C<i_fp_class>
-
-From F<i_fp_class.U>:
-
-This variable conditionally defines the C<I_FP_CLASS> symbol, and indicates
-whether a C program should include <fp_class.h>.
-
-=item C<i_gdbm>
-
-From F<i_gdbm.U>:
-
-This variable conditionally defines the C<I_GDBM> symbol, which
-indicates to the C program that <gdbm.h> exists and should
-be included.
-
-=item C<i_gdbm_ndbm>
-
-From F<i_ndbm.U>:
-
-This variable conditionally defines the C<I_GDBM_NDBM> symbol, which
-indicates to the C program that <gdbm-F<ndbm.h>> exists and should
-be included. This is the location of the F<ndbm.h> compatibility file
-in Debian 4.0.
-
-=item C<i_gdbmndbm>
-
-From F<i_ndbm.U>:
-
-This variable conditionally defines the C<I_GDBMNDBM> symbol, which
-indicates to the C program that <gdbm/ndbm.h> exists and should
-be included. This was the location of the F<ndbm.h> compatibility file
-in RedHat 7.1.
-
-=item C<i_grp>
-
-From F<i_grp.U>:
-
-This variable conditionally defines the C<I_GRP> symbol, and indicates
-whether a C program should include <grp.h>.
-
-=item C<i_ieeefp>
-
-From F<i_ieeefp.U>:
-
-This variable conditionally defines the C<I_IEEEFP> symbol, and indicates
-whether a C program should include <ieeefp.h>.
-
-=item C<i_inttypes>
-
-From F<i_inttypes.U>:
-
-This variable conditionally defines the C<I_INTTYPES> symbol,
-and indicates whether a C program should include <inttypes.h>.
-
-=item C<i_langinfo>
-
-From F<i_langinfo.U>:
-
-This variable conditionally defines the C<I_LANGINFO> symbol,
-and indicates whether a C program should include <langinfo.h>.
-
-=item C<i_libutil>
-
-From F<i_libutil.U>:
-
-This variable conditionally defines the C<I_LIBUTIL> symbol, and indicates
-whether a C program should include <libutil.h>.
-
-=item C<i_locale>
-
-From F<i_locale.U>:
-
-This variable conditionally defines the C<I_LOCALE> symbol,
-and indicates whether a C program should include <locale.h>.
-
-=item C<i_machcthr>
-
-From F<i_machcthr.U>:
-
-This variable conditionally defines the C<I_MACH_CTHREADS> symbol,
-and indicates whether a C program should include <mach/cthreads.h>.
-
-=item C<i_malloc>
-
-From F<i_malloc.U>:
-
-This variable conditionally defines the C<I_MALLOC> symbol, and indicates
-whether a C program should include <malloc.h>.
-
-=item C<i_mallocmalloc>
-
-From F<i_mallocmalloc.U>:
-
-This variable conditionally defines the C<I_MALLOCMALLOC> symbol,
-and indicates whether a C program should include <malloc/malloc.h>.
-
-=item C<i_mntent>
-
-From F<i_mntent.U>:
-
-This variable conditionally defines the C<I_MNTENT> symbol, and indicates
-whether a C program should include <mntent.h>.
-
-=item C<i_ndbm>
-
-From F<i_ndbm.U>:
-
-This variable conditionally defines the C<I_NDBM> symbol, which
-indicates to the C program that <ndbm.h> exists and should
-be included.
-
-=item C<i_netdb>
-
-From F<i_netdb.U>:
-
-This variable conditionally defines the C<I_NETDB> symbol, and indicates
-whether a C program should include <netdb.h>.
-
-=item C<i_neterrno>
-
-From F<i_neterrno.U>:
-
-This variable conditionally defines the C<I_NET_ERRNO> symbol, which
-indicates to the C program that <net/errno.h> exists and should
-be included.
-
-=item C<i_netinettcp>
-
-From F<i_netinettcp.U>:
-
-This variable conditionally defines the C<I_NETINET_TCP> symbol,
-and indicates whether a C program should include <netinet/tcp.h>.
-
-=item C<i_niin>
-
-From F<i_niin.U>:
-
-This variable conditionally defines C<I_NETINET_IN>, which indicates
-to the C program that it should include <netinet/in.h>. Otherwise,
-you may try <sys/in.h>.
-
-=item C<i_poll>
-
-From F<i_poll.U>:
-
-This variable conditionally defines the C<I_POLL> symbol, and indicates
-whether a C program should include <poll.h>.
-
-=item C<i_prot>
-
-From F<i_prot.U>:
-
-This variable conditionally defines the C<I_PROT> symbol, and indicates
-whether a C program should include <prot.h>.
-
-=item C<i_pthread>
-
-From F<i_pthread.U>:
-
-This variable conditionally defines the C<I_PTHREAD> symbol,
-and indicates whether a C program should include <pthread.h>.
-
-=item C<i_pwd>
-
-From F<i_pwd.U>:
-
-This variable conditionally defines C<I_PWD>, which indicates
-to the C program that it should include <pwd.h>.
-
-=item C<i_quadmath>
-
-From F<i_quadmath.U>:
-
-This variable conditionally defines C<I_QUADMATH>, which indicates
-to the C program that it should include <quadmath.h>.
-
-=item C<i_rpcsvcdbm>
-
-From F<i_dbm.U>:
-
-This variable conditionally defines the C<I_RPCSVC_DBM> symbol, which
-indicates to the C program that <rpcsvc/dbm.h> exists and should
-be included. Some System V systems might need this instead of <dbm.h>.
-
-=item C<i_sgtty>
-
-From F<i_termio.U>:
-
-This variable conditionally defines the C<I_SGTTY> symbol, which
-indicates to the C program that it should include <sgtty.h> rather
-than <termio.h>.
-
-=item C<i_shadow>
-
-From F<i_shadow.U>:
-
-This variable conditionally defines the C<I_SHADOW> symbol, and indicates
-whether a C program should include <shadow.h>.
-
-=item C<i_socks>
-
-From F<i_socks.U>:
-
-This variable conditionally defines the C<I_SOCKS> symbol, and indicates
-whether a C program should include <socks.h>.
-
-=item C<i_stdbool>
-
-From F<i_stdbool.U>:
-
-This variable conditionally defines the C<I_STDBOOL> symbol, which
-indicates to the C program that <stdbool.h> exists and should
-be included.
-
-=item C<i_stdint>
-
-From F<i_stdint.U>:
-
-This variable conditionally defines the C<I_STDINT> symbol, which
-indicates to the C program that <stdint.h> exists and should
-be included.
-
-=item C<i_stdlib>
-
-From F<i_stdlib.U>:
-
-This variable unconditionally defines the C<I_STDLIB> symbol.
-
-=item C<i_sunmath>
-
-From F<i_sunmath.U>:
-
-This variable conditionally defines the C<I_SUNMATH> symbol, and indicates
-whether a C program should include <sunmath.h>.
-
-=item C<i_sysaccess>
-
-From F<i_sysaccess.U>:
-
-This variable conditionally defines the C<I_SYS_ACCESS> symbol,
-and indicates whether a C program should include <sys/access.h>.
-
-=item C<i_sysdir>
-
-From F<i_sysdir.U>:
-
-This variable conditionally defines the C<I_SYS_DIR> symbol, and indicates
-whether a C program should include <sys/dir.h>.
-
-=item C<i_sysfile>
-
-From F<i_sysfile.U>:
-
-This variable conditionally defines the C<I_SYS_FILE> symbol, and indicates
-whether a C program should include <sys/file.h> to get C<R_OK> and friends.
-
-=item C<i_sysfilio>
-
-From F<i_sysioctl.U>:
-
-This variable conditionally defines the C<I_SYS_FILIO> symbol, which
-indicates to the C program that <sys/filio.h> exists and should
-be included in preference to <sys/ioctl.h>.
-
-=item C<i_sysin>
-
-From F<i_niin.U>:
-
-This variable conditionally defines C<I_SYS_IN>, which indicates
-to the C program that it should include <sys/in.h> instead of
-<netinet/in.h>.
-
-=item C<i_sysioctl>
-
-From F<i_sysioctl.U>:
-
-This variable conditionally defines the C<I_SYS_IOCTL> symbol, which
-indicates to the C program that <sys/ioctl.h> exists and should
-be included.
-
-=item C<i_syslog>
-
-From F<i_syslog.U>:
-
-This variable conditionally defines the C<I_SYSLOG> symbol,
-and indicates whether a C program should include <syslog.h>.
-
-=item C<i_sysmman>
-
-From F<i_sysmman.U>:
-
-This variable conditionally defines the C<I_SYS_MMAN> symbol,
-and indicates whether a C program should include <sys/mman.h>.
-
-=item C<i_sysmode>
-
-From F<i_sysmode.U>:
-
-This variable conditionally defines the C<I_SYSMODE> symbol,
-and indicates whether a C program should include <sys/mode.h>.
-
-=item C<i_sysmount>
-
-From F<i_sysmount.U>:
-
-This variable conditionally defines the C<I_SYSMOUNT> symbol,
-and indicates whether a C program should include <sys/mount.h>.
-
-=item C<i_sysndir>
-
-From F<i_sysndir.U>:
-
-This variable conditionally defines the C<I_SYS_NDIR> symbol, and indicates
-whether a C program should include <sys/ndir.h>.
-
-=item C<i_sysparam>
-
-From F<i_sysparam.U>:
-
-This variable conditionally defines the C<I_SYS_PARAM> symbol, and indicates
-whether a C program should include <sys/param.h>.
-
-=item C<i_syspoll>
-
-From F<i_syspoll.U>:
-
-This variable conditionally defines the C<I_SYS_POLL> symbol, which
-indicates to the C program that it should include <sys/poll.h>.
-
-=item C<i_sysresrc>
-
-From F<i_sysresrc.U>:
-
-This variable conditionally defines the C<I_SYS_RESOURCE> symbol,
-and indicates whether a C program should include <sys/resource.h>.
-
-=item C<i_syssecrt>
-
-From F<i_syssecrt.U>:
-
-This variable conditionally defines the C<I_SYS_SECURITY> symbol,
-and indicates whether a C program should include <sys/security.h>.
-
-=item C<i_sysselct>
-
-From F<i_sysselct.U>:
-
-This variable conditionally defines C<I_SYS_SELECT>, which indicates
-to the C program that it should include <sys/select.h> in order to
-get the definition of struct timeval.
-
-=item C<i_syssockio>
-
-From F<i_sysioctl.U>:
-
-This variable conditionally defines C<I_SYS_SOCKIO> to indicate to the
-C program that socket ioctl codes may be found in <sys/sockio.h>
-instead of <sys/ioctl.h>.
-
-=item C<i_sysstat>
-
-From F<i_sysstat.U>:
-
-This variable conditionally defines the C<I_SYS_STAT> symbol,
-and indicates whether a C program should include <sys/stat.h>.
-
-=item C<i_sysstatfs>
-
-From F<i_sysstatfs.U>:
-
-This variable conditionally defines the C<I_SYSSTATFS> symbol,
-and indicates whether a C program should include <sys/statfs.h>.
-
-=item C<i_sysstatvfs>
-
-From F<i_sysstatvfs.U>:
-
-This variable conditionally defines the C<I_SYSSTATVFS> symbol,
-and indicates whether a C program should include <sys/statvfs.h>.
-
-=item C<i_systime>
-
-From F<i_time.U>:
-
-This variable conditionally defines C<I_SYS_TIME>, which indicates
-to the C program that it should include <sys/time.h>.
-
-=item C<i_systimek>
-
-From F<i_time.U>:
-
-This variable conditionally defines C<I_SYS_TIME_KERNEL>, which
-indicates to the C program that it should include <sys/time.h>
-with C<KERNEL> defined.
-
-=item C<i_systimes>
-
-From F<i_systimes.U>:
-
-This variable conditionally defines the C<I_SYS_TIMES> symbol, and indicates
-whether a C program should include <sys/times.h>.
-
-=item C<i_systypes>
-
-From F<i_systypes.U>:
-
-This variable conditionally defines the C<I_SYS_TYPES> symbol,
-and indicates whether a C program should include <sys/types.h>.
-
-=item C<i_sysuio>
-
-From F<i_sysuio.U>:
-
-This variable conditionally defines the C<I_SYSUIO> symbol, and indicates
-whether a C program should include <sys/uio.h>.
-
-=item C<i_sysun>
-
-From F<i_sysun.U>:
-
-This variable conditionally defines C<I_SYS_UN>, which indicates
-to the C program that it should include <sys/un.h> to get C<UNIX>
-domain socket definitions.
-
-=item C<i_sysutsname>
-
-From F<i_sysutsname.U>:
-
-This variable conditionally defines the C<I_SYSUTSNAME> symbol,
-and indicates whether a C program should include <sys/utsname.h>.
-
-=item C<i_sysvfs>
-
-From F<i_sysvfs.U>:
-
-This variable conditionally defines the C<I_SYSVFS> symbol,
-and indicates whether a C program should include <sys/vfs.h>.
-
-=item C<i_syswait>
-
-From F<i_syswait.U>:
-
-This variable conditionally defines C<I_SYS_WAIT>, which indicates
-to the C program that it should include <sys/wait.h>.
-
-=item C<i_termio>
-
-From F<i_termio.U>:
-
-This variable conditionally defines the C<I_TERMIO> symbol, which
-indicates to the C program that it should include <termio.h> rather
-than <sgtty.h>.
-
-=item C<i_termios>
-
-From F<i_termio.U>:
-
-This variable conditionally defines the C<I_TERMIOS> symbol, which
-indicates to the C program that the C<POSIX> <termios.h> file is
-to be included.
-
-=item C<i_time>
-
-From F<i_time.U>:
-
-This variable unconditionally defines C<I_TIME>, which indicates
-to the C program that it should include <time.h>.
-
-=item C<i_unistd>
-
-From F<i_unistd.U>:
-
-This variable conditionally defines the C<I_UNISTD> symbol, and indicates
-whether a C program should include <unistd.h>.
-
-=item C<i_ustat>
-
-From F<i_ustat.U>:
-
-This variable conditionally defines the C<I_USTAT> symbol, and indicates
-whether a C program should include <ustat.h>.
-
-=item C<i_utime>
-
-From F<i_utime.U>:
-
-This variable conditionally defines the C<I_UTIME> symbol, and indicates
-whether a C program should include <utime.h>.
-
-=item C<i_vfork>
-
-From F<i_vfork.U>:
-
-This variable conditionally defines the C<I_VFORK> symbol, and indicates
-whether a C program should include F<vfork.h>.
-
-=item C<i_wchar>
-
-From F<i_wchar.U>:
-
-This variable conditionally defines the C<I_WCHAR> symbol,
-that indicates whether a C program may include <wchar.h>.
-
-=item C<i_wctype>
-
-From F<i_wctype.U>:
-
-This variable conditionally defines the C<I_WCTYPE> symbol,
-that indicates whether a C program may include <wctype.h>.
-
-=item C<i_xlocale>
-
-From F<d_newlocale.U>:
-
-This symbol, if defined, indicates to the C program that it should
-include <xlocale.h> to get uselocale() and its friends
-
-=item C<ignore_versioned_solibs>
-
-From F<libs.U>:
-
-This variable should be non-empty if non-versioned shared
-libraries (F<libfoo.so.x.y>) are to be ignored (because they
-cannot be linked against).
-
-=item C<inc_version_list>
-
-From F<inc_version_list.U>:
-
-This variable specifies the list of subdirectories in over
-which F<perl.c>:incpush() and F<lib/lib.pm> will automatically
-search when adding directories to @C<INC>. The elements in
-the list are separated by spaces. This is only useful
-if you have a perl library directory tree structured like the
-default one. See C<INSTALL> for how this works. The versioned
-site_perl directory was introduced in 5.005, so that is the
-lowest possible value.
-
-This list includes architecture-dependent directories back to
-version $api_versionstring (e.g. 5.5.640) and
-architecture-independent directories all the way back to
-5.005.
-
-=item C<inc_version_list_init>
-
-From F<inc_version_list.U>:
-
-This variable holds the same list as inc_version_list, but
-each item is enclosed in double quotes and separated by commas,
-suitable for use in the C<PERL_INC_VERSION_LIST> initialization.
-
-=item C<incpath>
-
-From F<usrinc.U>:
-
-This variable must precede the normal include path to get the
-right one, as in F<$incpath/usr/include> or F<$incpath/usr/lib>.
-Value can be "" or F</bsd43> on mips.
-
-=item C<incpth>
-
-From F<libpth.U>:
-
-This variable must precede the normal include path to get the
-right one, as in F<$incpath/usr/include> or F<$incpath/usr/lib>.
-Value can be "" or F</bsd43> on mips.
-
-=item C<inews>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<initialinstalllocation>
-
-From F<bin.U>:
-
-When userelocatableinc is true, this variable holds the location
-that make install should copy the perl binary to, with all the
-run-time relocatable paths calculated from this at install time.
-When used, it is initialized to the original value of binexp, and
-then binexp is set to F<.../>, as the other binaries are found
-relative to the perl binary.
-
-=item C<installarchlib>
-
-From F<archlib.U>:
-
-This variable is really the same as archlibexp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<installbin>
-
-From F<bin.U>:
-
-This variable is the same as binexp unless C<AFS> is running in which case
-the user is explicitly prompted for it. This variable should always
-be used in your makefiles for maximum portability.
-
-=item C<installhtml1dir>
-
-From F<html1dir.U>:
-
-This variable is really the same as html1direxp, unless you are
-using a different installprefix. For extra portability, you
-should only use this variable within your makefiles.
-
-=item C<installhtml3dir>
-
-From F<html3dir.U>:
-
-This variable is really the same as html3direxp, unless you are
-using a different installprefix. For extra portability, you
-should only use this variable within your makefiles.
-
-=item C<installman1dir>
-
-From F<man1dir.U>:
-
-This variable is really the same as man1direxp, unless you are using
-C<AFS> in which case it points to the read/write location whereas
-man1direxp only points to the read-only access location. For extra
-portability, you should only use this variable within your makefiles.
-
-=item C<installman3dir>
-
-From F<man3dir.U>:
-
-This variable is really the same as man3direxp, unless you are using
-C<AFS> in which case it points to the read/write location whereas
-man3direxp only points to the read-only access location. For extra
-portability, you should only use this variable within your makefiles.
-
-=item C<installprefix>
-
-From F<installprefix.U>:
-
-This variable holds the name of the directory below which
-"make install" will install the package. For most users, this
-is the same as prefix. However, it is useful for
-installing the software into a different (usually temporary)
-location after which it can be bundled up and moved somehow
-to the final location specified by prefix.
-
-=item C<installprefixexp>
-
-From F<installprefix.U>:
-
-This variable holds the full absolute path of installprefix
-with all F<~>-expansion done.
-
-=item C<installprivlib>
-
-From F<privlib.U>:
-
-This variable is really the same as privlibexp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<installscript>
-
-From F<scriptdir.U>:
-
-This variable is usually the same as scriptdirexp, unless you are on
-a system running C<AFS>, in which case they may differ slightly. You
-should always use this variable within your makefiles for portability.
-
-=item C<installsitearch>
-
-From F<sitearch.U>:
-
-This variable is really the same as sitearchexp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<installsitebin>
-
-From F<sitebin.U>:
-
-This variable is usually the same as sitebinexp, unless you are on
-a system running C<AFS>, in which case they may differ slightly. You
-should always use this variable within your makefiles for portability.
-
-=item C<installsitehtml1dir>
-
-From F<sitehtml1dir.U>:
-
-This variable is really the same as sitehtml1direxp, unless you are using
-C<AFS> in which case it points to the read/write location whereas
-html1direxp only points to the read-only access location. For extra
-portability, you should only use this variable within your makefiles.
-
-=item C<installsitehtml3dir>
-
-From F<sitehtml3dir.U>:
-
-This variable is really the same as sitehtml3direxp, unless you are using
-C<AFS> in which case it points to the read/write location whereas
-html3direxp only points to the read-only access location. For extra
-portability, you should only use this variable within your makefiles.
-
-=item C<installsitelib>
-
-From F<sitelib.U>:
-
-This variable is really the same as sitelibexp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<installsiteman1dir>
-
-From F<siteman1dir.U>:
-
-This variable is really the same as siteman1direxp, unless you are using
-C<AFS> in which case it points to the read/write location whereas
-man1direxp only points to the read-only access location. For extra
-portability, you should only use this variable within your makefiles.
-
-=item C<installsiteman3dir>
-
-From F<siteman3dir.U>:
-
-This variable is really the same as siteman3direxp, unless you are using
-C<AFS> in which case it points to the read/write location whereas
-man3direxp only points to the read-only access location. For extra
-portability, you should only use this variable within your makefiles.
-
-=item C<installsitescript>
-
-From F<sitescript.U>:
-
-This variable is usually the same as sitescriptexp, unless you are on
-a system running C<AFS>, in which case they may differ slightly. You
-should always use this variable within your makefiles for portability.
-
-=item C<installstyle>
-
-From F<installstyle.U>:
-
-This variable describes the C<style> of the perl installation.
-This is intended to be useful for tools that need to
-manipulate entire perl distributions. Perl itself doesn't use
-this to find its libraries -- the library directories are
-stored directly in F<Config.pm>. Currently, there are only two
-styles: C<lib> and F<lib/perl5>. The default library locations
-(e.g. privlib, sitelib) are either F<$prefix/lib> or
-F<$prefix/lib/perl5>. The former is useful if $prefix is a
-directory dedicated to perl (e.g. F</opt/perl>), while the latter
-is useful if $prefix is shared by many packages, e.g. if
-$prefix=F</usr/local>.
-
-Unfortunately, while this C<style> variable is used to set
-defaults for all three directory hierarchies (core, vendor, and
-site), there is no guarantee that the same style is actually
-appropriate for all those directories. For example, $prefix
-might be F</opt/perl>, but $siteprefix might be F</usr/local>.
-(Perhaps, in retrospect, the C<lib> style should never have been
-supported, but it did seem like a nice idea at the time.)
-
-The situation is even less clear for tools such as MakeMaker
-that can be used to install additional modules into
-non-standard places. For example, if a user intends to install
-a module into a private directory (perhaps by setting C<PREFIX> on
-the F<Makefile.PL> command line), then there is no reason to
-assume that the Configure-time $installstyle setting will be
-relevant for that C<PREFIX>.
-
-This may later be extended to include other information, so
-be careful with pattern-matching on the results.
-
-For compatibility with F<perl5.005> and earlier, the default
-setting is based on whether or not $prefix contains the string
-C<perl>.
-
-=item C<installusrbinperl>
-
-From F<instubperl.U>:
-
-This variable tells whether Perl should be installed also as
-F</usr/bin/perl> in addition to
-F<$installbin/perl>
-
-=item C<installvendorarch>
-
-From F<vendorarch.U>:
-
-This variable is really the same as vendorarchexp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<installvendorbin>
-
-From F<vendorbin.U>:
-
-This variable is really the same as vendorbinexp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<installvendorhtml1dir>
-
-From F<vendorhtml1dir.U>:
-
-This variable is really the same as vendorhtml1direxp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<installvendorhtml3dir>
-
-From F<vendorhtml3dir.U>:
-
-This variable is really the same as vendorhtml3direxp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<installvendorlib>
-
-From F<vendorlib.U>:
-
-This variable is really the same as vendorlibexp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<installvendorman1dir>
-
-From F<vendorman1dir.U>:
-
-This variable is really the same as vendorman1direxp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<installvendorman3dir>
-
-From F<vendorman3dir.U>:
-
-This variable is really the same as vendorman3direxp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<installvendorscript>
-
-From F<vendorscript.U>:
-
-This variable is really the same as vendorscriptexp but may differ on
-those systems using C<AFS>. For extra portability, only this variable
-should be used in makefiles.
-
-=item C<intsize>
-
-From F<intsize.U>:
-
-This variable contains the value of the C<INTSIZE> symbol, which
-indicates to the C program how many bytes there are in an int.
-
-=item C<issymlink>
-
-From F<issymlink.U>:
-
-This variable holds the test command to test for a symbolic link
-(if they are supported). Typical values include C<test -h> and
-C<test -L>.
-
-=item C<ivdformat>
-
-From F<perlxvf.U>:
-
-This variable contains the format string used for printing
-a Perl C<IV> as a signed decimal integer.
-
-=item C<ivsize>
-
-From F<perlxv.U>:
-
-This variable is the size of an C<IV> in bytes.
-
-=item C<ivtype>
-
-From F<perlxv.U>:
-
-This variable contains the C type used for Perl's C<IV>.
-
-=back
-
-=head2 k
-
-=over 4
-
-=item C<known_extensions>
-
-From F<Extensions.U>:
-
-This variable holds a list of all extensions (both C<XS> and non-xs)
-included in the package source distribution. This information is
-only really of use during the Perl build, as the list makes no
-distinction between extensions which were build and installed, and
-those which where not. See C<extensions> for the list of extensions
-actually built and available.
-
-=item C<ksh>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=back
-
-=head2 l
-
-=over 4
-
-=item C<ld>
-
-From F<dlsrc.U>:
-
-This variable indicates the program to be used to link
-libraries for dynamic loading. On some systems, it is C<ld>.
-On C<ELF> systems, it should be $cc. Mostly, we'll try to respect
-the hint file setting.
-
-=item C<ld_can_script>
-
-From F<dlsrc.U>:
-
-This variable shows if the loader accepts scripts in the form of
--Wl,--version-script=F<ld.script>. This is currently only supported
-for C<GNU> ld on C<ELF> in dynamic loading builds.
-
-=item C<lddlflags>
-
-From F<dlsrc.U>:
-
-This variable contains any special flags that might need to be
-passed to $ld to create a shared library suitable for dynamic
-loading. It is up to the makefile to use it. For hpux, it
-should be C<-b>. For sunos 4.1, it is empty.
-
-=item C<ldflags>
-
-From F<ccflags.U>:
-
-This variable contains any additional C loader flags desired by
-the user. It is up to the Makefile to use this.
-
-=item C<ldflags_uselargefiles>
-
-From F<uselfs.U>:
-
-This variable contains the loader flags needed by large file builds
-and added to ldflags by hints files.
-
-=item C<ldlibpthname>
-
-From F<libperl.U>:
-
-This variable holds the name of the shared library
-search path, often C<LD_LIBRARY_PATH>. To get an empty
-string, the hints file must set this to C<none>.
-
-=item C<less>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the less program. After Configure runs,
-the value is reset to a plain C<less> and is not useful.
-
-=item C<lib_ext>
-
-From F<Unix.U>:
-
-This is an old synonym for _a.
-
-=item C<libc>
-
-From F<libc.U>:
-
-This variable contains the location of the C library.
-
-=item C<libperl>
-
-From F<libperl.U>:
-
-The perl executable is obtained by linking F<perlmain.c> with
-libperl, any static extensions (usually just DynaLoader),
-and any other libraries needed on this system. libperl
-is usually F<libperl.a>, but can also be F<libperl.so.xxx> if
-the user wishes to build a perl executable with a shared
-library.
-
-=item C<libpth>
-
-From F<libpth.U>:
-
-This variable holds the general path (space-separated) used to find
-libraries. It is intended to be used by other units.
-
-=item C<libs>
-
-From F<libs.U>:
-
-This variable holds the additional libraries we want to use.
-It is up to the Makefile to deal with it. The list can be empty.
-
-=item C<libsdirs>
-
-From F<libs.U>:
-
-This variable holds the directory names aka dirnames of the libraries
-we found and accepted, duplicates are removed.
-
-=item C<libsfiles>
-
-From F<libs.U>:
-
-This variable holds the filenames aka basenames of the libraries
-we found and accepted.
-
-=item C<libsfound>
-
-From F<libs.U>:
-
-This variable holds the full pathnames of the libraries
-we found and accepted.
-
-=item C<libspath>
-
-From F<libs.U>:
-
-This variable holds the directory names probed for libraries.
-
-=item C<libswanted>
-
-From F<Myinit.U>:
-
-This variable holds a list of all the libraries we want to
-search. The order is chosen to pick up the c library
-ahead of ucb or bsd libraries for SVR4.
-
-=item C<libswanted_uselargefiles>
-
-From F<uselfs.U>:
-
-This variable contains the libraries needed by large file builds
-and added to ldflags by hints files. It is a space separated list
-of the library names without the C<lib> prefix or any suffix, just
-like F<libswanted.>.
-
-=item C<line>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<lint>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<lkflags>
-
-From F<ccflags.U>:
-
-This variable contains any additional C partial linker flags desired by
-the user. It is up to the Makefile to use this.
-
-=item C<ln>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the ln program. After Configure runs,
-the value is reset to a plain C<ln> and is not useful.
-
-=item C<lns>
-
-From F<lns.U>:
-
-This variable holds the name of the command to make
-symbolic links (if they are supported). It can be used
-in the Makefile. It is either C<ln -s> or C<ln>
-
-=item C<localtime_r_proto>
-
-From F<d_localtime_r.U>:
-
-This variable encodes the prototype of localtime_r.
-It is zero if d_localtime_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_localtime_r
-is defined.
-
-=item C<locincpth>
-
-From F<ccflags.U>:
-
-This variable contains a list of additional directories to be
-searched by the compiler. The appropriate C<-I> directives will
-be added to ccflags. This is intended to simplify setting
-local directories from the Configure command line.
-It's not much, but it parallels the loclibpth stuff in F<libpth.U>.
-
-=item C<loclibpth>
-
-From F<libpth.U>:
-
-This variable holds the paths (space-separated) used to find local
-libraries. It is prepended to libpth, and is intended to be easily
-set from the command line.
-
-=item C<longdblinfbytes>
-
-From F<infnan.U>:
-
-This variable contains comma-separated list of hexadecimal bytes
-for the long double precision infinity.
-
-=item C<longdblkind>
-
-From F<d_longdbl.U>:
-
-This variable, if defined, encodes the type of a long double:
-0 = double,
-1 = C<IEEE> 754 128-bit little endian,
-2 = C<IEEE> 754 128-bit big endian,
-3 = x86 80-bit little endian,
-4 = x86 80-bit big endian,
-5 = double-double 128-bit little endian,
-6 = double-double 128-bit big endian,
-7 = 128-bit mixed-endian double-double (64-bit LEs in C<BE>),
-8 = 128-bit mixed-endian double-double (64-bit BEs in C<LE>),
-9 = 128-bit C<PDP>-style mixed-endian long doubles,
--1 = unknown format.
-
-=item C<longdblmantbits>
-
-From F<mantbits.U>:
-
-This symbol, if defined, tells how many mantissa bits
-there are in long double precision floating point format.
-Note that this can be C<LDBL_MANT_DIG> minus one,
-since C<LDBL_MANT_DIG> can include the C<IEEE> 754 implicit bit.
-The common x86-style 80-bit long double does not have
-an implicit bit.
-
-=item C<longdblnanbytes>
-
-From F<infnan.U>:
-
-This variable contains comma-separated list of hexadecimal bytes
-for the long double precision not-a-number.
-
-=item C<longdblsize>
-
-From F<d_longdbl.U>:
-
-This variable contains the value of the C<LONG_DOUBLESIZE> symbol, which
-indicates to the C program how many bytes there are in a long double,
-if this system supports long doubles. Note that this is
-sizeof(long double), which may include unused bytes.
-
-=item C<longlongsize>
-
-From F<d_longlong.U>:
-
-This variable contains the value of the C<LONGLONGSIZE> symbol, which
-indicates to the C program how many bytes there are in a long long,
-if this system supports long long.
-
-=item C<longsize>
-
-From F<intsize.U>:
-
-This variable contains the value of the C<LONGSIZE> symbol, which
-indicates to the C program how many bytes there are in a long.
-
-=item C<lp>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<lpr>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<ls>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the ls program. After Configure runs,
-the value is reset to a plain C<ls> and is not useful.
-
-=item C<lseeksize>
-
-From F<lseektype.U>:
-
-This variable defines lseektype to be something like off_t, long,
-or whatever type is used to declare lseek offset's type in the
-kernel (which also appears to be lseek's return type).
-
-=item C<lseektype>
-
-From F<lseektype.U>:
-
-This variable defines lseektype to be something like off_t, long,
-or whatever type is used to declare lseek offset's type in the
-kernel (which also appears to be lseek's return type).
-
-=back
-
-=head2 m
-
-=over 4
-
-=item C<mail>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<mailx>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<make>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the make program. After Configure runs,
-the value is reset to a plain C<make> and is not useful.
-
-=item C<make_set_make>
-
-From F<make.U>:
-
-Some versions of C<make> set the variable C<MAKE>. Others do not.
-This variable contains the string to be included in F<Makefile.SH>
-so that C<MAKE> is set if needed, and not if not needed.
-Possible values are:
-
-make_set_make=C<#> # If your make program handles this for you,
-
-make_set_make=C<MAKE=$make> # if it doesn't.
-
-This uses a comment character so that we can distinguish a
-C<set> value (from a previous F<config.sh> or Configure C<-D> option)
-from an uncomputed value.
-
-=item C<mallocobj>
-
-From F<mallocsrc.U>:
-
-This variable contains the name of the F<malloc.o> that this package
-generates, if that F<malloc.o> is preferred over the system malloc.
-Otherwise the value is null. This variable is intended for generating
-Makefiles. See mallocsrc.
-
-=item C<mallocsrc>
-
-From F<mallocsrc.U>:
-
-This variable contains the name of the F<malloc.c> that comes with
-the package, if that F<malloc.c> is preferred over the system malloc.
-Otherwise the value is null. This variable is intended for generating
-Makefiles.
-
-=item C<malloctype>
-
-From F<mallocsrc.U>:
-
-This variable contains the kind of ptr returned by malloc and realloc.
-
-=item C<man1dir>
-
-From F<man1dir.U>:
-
-This variable contains the name of the directory in which manual
-source pages are to be put. It is the responsibility of the
-F<Makefile.SH> to get the value of this into the proper command.
-You must be prepared to do the F<~name> expansion yourself.
-
-=item C<man1direxp>
-
-From F<man1dir.U>:
-
-This variable is the same as the man1dir variable, but is filename
-expanded at configuration time, for convenient use in makefiles.
-
-=item C<man1ext>
-
-From F<man1dir.U>:
-
-This variable contains the extension that the manual page should
-have: one of C<n>, C<l>, or C<1>. The Makefile must supply the F<.>.
-See man1dir.
-
-=item C<man3dir>
-
-From F<man3dir.U>:
-
-This variable contains the name of the directory in which manual
-source pages are to be put. It is the responsibility of the
-F<Makefile.SH> to get the value of this into the proper command.
-You must be prepared to do the F<~name> expansion yourself.
-
-=item C<man3direxp>
-
-From F<man3dir.U>:
-
-This variable is the same as the man3dir variable, but is filename
-expanded at configuration time, for convenient use in makefiles.
-
-=item C<man3ext>
-
-From F<man3dir.U>:
-
-This variable contains the extension that the manual page should
-have: one of C<n>, C<l>, or C<3>. The Makefile must supply the F<.>.
-See man3dir.
-
-=item C<mips_type>
-
-From F<usrinc.U>:
-
-This variable holds the environment type for the mips system.
-Possible values are "BSD 4.3" and "System V".
-
-=item C<mistrustnm>
-
-From F<Csym.U>:
-
-This variable can be used to establish a fallthrough for the cases
-where nm fails to find a symbol. If usenm is false or usenm is true
-and mistrustnm is false, this variable has no effect. If usenm is true
-and mistrustnm is C<compile>, a test program will be compiled to try to
-find any symbol that can't be located via nm lookup. If mistrustnm is
-C<run>, the test program will be run as well as being compiled.
-
-=item C<mkdir>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the mkdir program. After Configure runs,
-the value is reset to a plain C<mkdir> and is not useful.
-
-=item C<mmaptype>
-
-From F<d_mmap.U>:
-
-This symbol contains the type of pointer returned by mmap()
-(and simultaneously the type of the first argument).
-It can be C<void *> or C<caddr_t>.
-
-=item C<modetype>
-
-From F<modetype.U>:
-
-This variable defines modetype to be something like mode_t,
-int, unsigned short, or whatever type is used to declare file
-modes for system calls.
-
-=item C<more>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the more program. After Configure runs,
-the value is reset to a plain C<more> and is not useful.
-
-=item C<multiarch>
-
-From F<multiarch.U>:
-
-This variable conditionally defines the C<MULTIARCH> symbol
-which signifies the presence of multiplatform files.
-This is normally set by hints files.
-
-=item C<mv>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<myarchname>
-
-From F<archname.U>:
-
-This variable holds the architecture name computed by Configure in
-a previous run. It is not intended to be perused by any user and
-should never be set in a hint file.
-
-=item C<mydomain>
-
-From F<myhostname.U>:
-
-This variable contains the eventual value of the C<MYDOMAIN> symbol,
-which is the domain of the host the program is going to run on.
-The domain must be appended to myhostname to form a complete host name.
-The dot comes with mydomain, and need not be supplied by the program.
-
-=item C<myhostname>
-
-From F<myhostname.U>:
-
-This variable contains the eventual value of the C<MYHOSTNAME> symbol,
-which is the name of the host the program is going to run on.
-The domain is not kept with hostname, but must be gotten from mydomain.
-The dot comes with mydomain, and need not be supplied by the program.
-
-=item C<myuname>
-
-From F<Oldconfig.U>:
-
-The output of C<uname -a> if available, otherwise the hostname.
-The whole thing is then lower-cased and slashes and single quotes are
-removed.
-
-=back
-
-=head2 n
-
-=over 4
-
-=item C<n>
-
-From F<n.U>:
-
-This variable contains the C<-n> flag if that is what causes the echo
-command to suppress newline. Otherwise it is null. Correct usage is
-$echo $n "prompt for a question: $c".
-
-=item C<need_va_copy>
-
-From F<need_va_copy.U>:
-
-This symbol, if defined, indicates that the system stores
-the variable argument list datatype, va_list, in a format
-that cannot be copied by simple assignment, so that some
-other means must be used when copying is required.
-As such systems vary in their provision (or non-provision)
-of copying mechanisms, F<handy.h> defines a platform-
-C<independent> macro, Perl_va_copy(src, dst), to do the job.
-
-=item C<netdb_hlen_type>
-
-From F<netdbtype.U>:
-
-This variable holds the type used for the 2nd argument to
-gethostbyaddr(). Usually, this is int or size_t or unsigned.
-This is only useful if you have gethostbyaddr(), naturally.
-
-=item C<netdb_host_type>
-
-From F<netdbtype.U>:
-
-This variable holds the type used for the 1st argument to
-gethostbyaddr(). Usually, this is char * or void *, possibly
-with or without a const prefix.
-This is only useful if you have gethostbyaddr(), naturally.
-
-=item C<netdb_name_type>
-
-From F<netdbtype.U>:
-
-This variable holds the type used for the argument to
-gethostbyname(). Usually, this is char * or const char *.
-This is only useful if you have gethostbyname(), naturally.
-
-=item C<netdb_net_type>
-
-From F<netdbtype.U>:
-
-This variable holds the type used for the 1st argument to
-getnetbyaddr(). Usually, this is int or long.
-This is only useful if you have getnetbyaddr(), naturally.
-
-=item C<nm>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the nm program. After Configure runs,
-the value is reset to a plain C<nm> and is not useful.
-
-=item C<nm_opt>
-
-From F<usenm.U>:
-
-This variable holds the options that may be necessary for nm.
-
-=item C<nm_so_opt>
-
-From F<usenm.U>:
-
-This variable holds the options that may be necessary for nm
-to work on a shared library but that can not be used on an
-archive library. Currently, this is only used by Linux, where
-nm --dynamic is *required* to get symbols from an C<ELF> library which
-has been stripped, but nm --dynamic is *fatal* on an archive library.
-Maybe Linux should just always set usenm=false.
-
-=item C<nonxs_ext>
-
-From F<Extensions.U>:
-
-This variable holds a list of all non-xs extensions built and
-installed by the package. By default, all non-xs extensions
-distributed will be built, with the exception of platform-specific
-extensions (currently only one C<VMS> specific extension).
-
-=item C<nroff>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the nroff program. After Configure runs,
-the value is reset to a plain C<nroff> and is not useful.
-
-=item C<nv_overflows_integers_at>
-
-From F<perlxv.U>:
-
-This variable gives the largest integer value that NVs can hold
-as a constant floating point expression.
-If it could not be determined, it holds the value 0.
-
-=item C<nv_preserves_uv_bits>
-
-From F<perlxv.U>:
-
-This variable indicates how many of bits type uvtype
-a variable nvtype can preserve.
-
-=item C<nveformat>
-
-From F<perlxvf.U>:
-
-This variable contains the format string used for printing
-a Perl C<NV> using %e-ish floating point format.
-
-=item C<nvEUformat>
-
-From F<perlxvf.U>:
-
-This variable contains the format string used for printing
-a Perl C<NV> using %E-ish floating point format.
-
-=item C<nvfformat>
-
-From F<perlxvf.U>:
-
-This variable contains the format string used for printing
-a Perl C<NV> using %f-ish floating point format.
-
-=item C<nvFUformat>
-
-From F<perlxvf.U>:
-
-This variable contains the format string used for printing
-a Perl C<NV> using %F-ish floating point format.
-
-=item C<nvgformat>
-
-From F<perlxvf.U>:
-
-This variable contains the format string used for printing
-a Perl C<NV> using %g-ish floating point format.
-
-=item C<nvGUformat>
-
-From F<perlxvf.U>:
-
-This variable contains the format string used for printing
-a Perl C<NV> using %G-ish floating point format.
-
-=item C<nvmantbits>
-
-From F<mantbits.U>:
-
-This variable tells how many bits the mantissa of a Perl C<NV> has,
-not including the possible implicit bit.
-
-=item C<nvsize>
-
-From F<perlxv.U>:
-
-This variable is the size of a Perl C<NV> in bytes.
-Note that some floating point formats have unused bytes.
-
-=item C<nvtype>
-
-From F<perlxv.U>:
-
-This variable contains the C type used for Perl's C<NV>.
-
-=back
-
-=head2 o
-
-=over 4
-
-=item C<o_nonblock>
-
-From F<nblock_io.U>:
-
-This variable bears the symbol value to be used during open() or fcntl()
-to turn on non-blocking I/O for a file descriptor. If you wish to switch
-between blocking and non-blocking, you may try ioctl(C<FIOSNBIO>) instead,
-but that is only supported by some devices.
-
-=item C<obj_ext>
-
-From F<Unix.U>:
-
-This is an old synonym for _o.
-
-=item C<old_pthread_create_joinable>
-
-From F<d_pthrattrj.U>:
-
-This variable defines the constant to use for creating joinable
-(aka undetached) pthreads. Unused if F<pthread.h> defines
-C<PTHREAD_CREATE_JOINABLE>. If used, possible values are
-C<PTHREAD_CREATE_UNDETACHED> and C<__UNDETACHED>.
-
-=item C<optimize>
-
-From F<ccflags.U>:
-
-This variable contains any F<optimizer/debugger> flag that should be used.
-It is up to the Makefile to use it.
-
-=item C<orderlib>
-
-From F<orderlib.U>:
-
-This variable is C<true> if the components of libraries must be ordered
-(with `lorder $* | tsort`) before placing them in an archive. Set to
-C<false> if ranlib or ar can generate random libraries.
-
-=item C<osname>
-
-From F<Oldconfig.U>:
-
-This variable contains the operating system name (e.g. sunos,
-solaris, hpux, etc.). It can be useful later on for setting
-defaults. Any spaces are replaced with underscores. It is set
-to a null string if we can't figure it out.
-
-=item C<osvers>
-
-From F<Oldconfig.U>:
-
-This variable contains the operating system version (e.g.
-4.1.3, 5.2, etc.). It is primarily used for helping select
-an appropriate hints file, but might be useful elsewhere for
-setting defaults. It is set to '' if we can't figure it out.
-We try to be flexible about how much of the version number
-to keep, e.g. if 4.1.1, 4.1.2, and 4.1.3 are essentially the
-same for this package, hints files might just be F<os_4.0> or
-F<os_4.1>, etc., not keeping separate files for each little release.
-
-=item C<otherlibdirs>
-
-From F<otherlibdirs.U>:
-
-This variable contains a colon-separated set of paths for the perl
-binary to search for additional library files or modules.
-These directories will be tacked to the end of @C<INC>.
-Perl will automatically search below each path for version-
-and architecture-specific directories. See inc_version_list
-for more details.
-A value of C< > means C<none> and is used to preserve this value
-for the next run through Configure.
-
-=back
-
-=head2 p
-
-=over 4
-
-=item C<package>
-
-From F<package.U>:
-
-This variable contains the name of the package being constructed.
-It is primarily intended for the use of later Configure units.
-
-=item C<pager>
-
-From F<pager.U>:
-
-This variable contains the name of the preferred pager on the system.
-Usual values are (the full pathnames of) more, less, pg, or cat.
-
-=item C<passcat>
-
-From F<nis.U>:
-
-This variable contains a command that produces the text of the
-F</etc/passwd> file. This is normally "cat F</etc/passwd>", but can be
-"ypcat passwd" when C<NIS> is used.
-On some systems, such as os390, there may be no equivalent
-command, in which case this variable is unset.
-
-=item C<patchlevel>
-
-From F<patchlevel.U>:
-
-The patchlevel level of this package.
-The value of patchlevel comes from the F<patchlevel.h> file.
-In a version number such as 5.6.1, this is the C<6>.
-In F<patchlevel.h>, this is referred to as C<PERL_VERSION>.
-
-=item C<path_sep>
-
-From F<Unix.U>:
-
-This is an old synonym for p_ in F<Head.U>, the character
-used to separate elements in the command shell search C<PATH>.
-
-=item C<perl>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the perl program. After Configure runs,
-the value is reset to a plain C<perl> and is not useful.
-
-=item C<perl5>
-
-From F<perl5.U>:
-
-This variable contains the full path (if any) to a previously
-installed F<perl5.005> or later suitable for running the script
-to determine inc_version_list.
-
-=back
-
-=head2 P
-
-=over 4
-
-=item C<PERL_API_REVISION>
-
-From F<patchlevel.h>:
-
-This number describes the earliest compatible C<PERL_REVISION> of
-Perl (C<compatibility> here being defined as sufficient F<binary/C<API>>
-compatibility to run C<XS> code built with the older version).
-Normally this does not change across maintenance releases.
-Please read the comment in F<patchlevel.h>.
-
-=item C<PERL_API_SUBVERSION>
-
-From F<patchlevel.h>:
-
-This number describes the earliest compatible C<PERL_SUBVERSION> of
-Perl (C<compatibility> here being defined as sufficient F<binary/C<API>>
-compatibility to run C<XS> code built with the older version).
-Normally this does not change across maintenance releases.
-Please read the comment in F<patchlevel.h>.
-
-=item C<PERL_API_VERSION>
-
-From F<patchlevel.h>:
-
-This number describes the earliest compatible C<PERL_VERSION> of
-Perl (C<compatibility> here being defined as sufficient F<binary/C<API>>
-compatibility to run C<XS> code built with the older version).
-Normally this does not change across maintenance releases.
-Please read the comment in F<patchlevel.h>.
-
-=item C<PERL_CONFIG_SH>
-
-From F<Oldsyms.U>:
-
-This is set to C<true> in F<config.sh> so that a shell script
-sourcing F<config.sh> can tell if it has been sourced already.
-
-=item C<PERL_PATCHLEVEL>
-
-From F<Oldsyms.U>:
-
-This symbol reflects the patchlevel, if available. Will usually
-come from the F<.patch> file, which is available when the perl
-source tree was fetched with rsync.
-
-=item C<perl_patchlevel>
-
-From F<patchlevel.U>:
-
-This is the Perl patch level, a numeric change identifier,
-as defined by whichever source code maintenance system
-is used to maintain the patches; currently Perforce.
-It does not correlate with the Perl version numbers or
-the maintenance versus development dichotomy except
-by also being increasing.
-
-=item C<PERL_REVISION>
-
-From F<Oldsyms.U>:
-
-In a Perl version number such as 5.6.2, this is the 5.
-This value is manually set in F<patchlevel.h>
-
-=item C<perl_static_inline>
-
-From F<d_static_inline.U>:
-
-This variable defines the C<PERL_STATIC_INLINE> symbol to
-the best-guess incantation to use for static inline functions.
-Possibilities include
-static inline (c99)
-static __inline__ (gcc -ansi)
-static __inline (C<MSVC>)
-static _inline (older C<MSVC>)
-static (c89 compilers)
-
-=item C<PERL_SUBVERSION>
-
-From F<Oldsyms.U>:
-
-In a Perl version number such as 5.6.2, this is the 2.
-Values greater than 50 represent potentially unstable
-development subversions.
-This value is manually set in F<patchlevel.h>
-
-=item C<PERL_VERSION>
-
-From F<Oldsyms.U>:
-
-In a Perl version number such as 5.6.2, this is the 6.
-This value is manually set in F<patchlevel.h>
-
-=item C<perladmin>
-
-From F<perladmin.U>:
-
-Electronic mail address of the perl5 administrator.
-
-=item C<perllibs>
-
-From F<End.U>:
-
-The list of libraries needed by Perl only (any libraries needed
-by extensions only will by dropped, if using dynamic loading).
-
-=item C<perlpath>
-
-From F<perlpath.U>:
-
-This variable contains the eventual value of the C<PERLPATH> symbol,
-which contains the name of the perl interpreter to be used in
-shell scripts and in the "eval C<exec>" idiom. This variable is
-not necessarily the pathname of the file containing the perl
-interpreter; you must append the executable extension (_exe) if
-it is not already present. Note that Perl code that runs during
-the Perl build process cannot reference this variable, as Perl
-may not have been installed, or even if installed, may be a
-different version of Perl.
-
-=item C<pg>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the pg program. After Configure runs,
-the value is reset to a plain C<pg> and is not useful.
-
-=item C<phostname>
-
-From F<myhostname.U>:
-
-This variable contains the eventual value of the C<PHOSTNAME> symbol,
-which is a command that can be fed to popen() to get the host name.
-The program should probably not presume that the domain is or isn't
-there already.
-
-=item C<pidtype>
-
-From F<pidtype.U>:
-
-This variable defines C<PIDTYPE> to be something like pid_t, int,
-ushort, or whatever type is used to declare process ids in the kernel.
-
-=item C<plibpth>
-
-From F<libpth.U>:
-
-Holds the private path used by Configure to find out the libraries.
-Its value is prepend to libpth. This variable takes care of special
-machines, like the mips. Usually, it should be empty.
-
-=item C<pmake>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<pr>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<prefix>
-
-From F<prefix.U>:
-
-This variable holds the name of the directory below which the
-user will install the package. Usually, this is F</usr/local>, and
-executables go in F</usr/local/bin>, library stuff in F</usr/local/lib>,
-man pages in F</usr/local/man>, etc. It is only used to set defaults
-for things in F<bin.U>, F<mansrc.U>, F<privlib.U>, or F<scriptdir.U>.
-
-=item C<prefixexp>
-
-From F<prefix.U>:
-
-This variable holds the full absolute path of the directory below
-which the user will install the package. Derived from prefix.
-
-=item C<privlib>
-
-From F<privlib.U>:
-
-This variable contains the eventual value of the C<PRIVLIB> symbol,
-which is the name of the private library for this package. It may
-have a F<~> on the front. It is up to the makefile to eventually create
-this directory while performing installation (with F<~> substitution).
-
-=item C<privlibexp>
-
-From F<privlib.U>:
-
-This variable is the F<~name> expanded version of privlib, so that you
-may use it directly in Makefiles or shell scripts.
-
-=item C<procselfexe>
-
-From F<d_procselfexe.U>:
-
-If d_procselfexe is defined, $procselfexe is the filename
-of the symbolic link pointing to the absolute pathname of
-the executing program.
-
-=item C<ptrsize>
-
-From F<ptrsize.U>:
-
-This variable contains the value of the C<PTRSIZE> symbol, which
-indicates to the C program how many bytes there are in a pointer.
-
-=back
-
-=head2 q
-
-=over 4
-
-=item C<quadkind>
-
-From F<quadtype.U>:
-
-This variable, if defined, encodes the type of a quad:
-1 = int, 2 = long, 3 = long long, 4 = int64_t.
-
-=item C<quadtype>
-
-From F<quadtype.U>:
-
-This variable defines Quad_t to be something like long, int,
-long long, int64_t, or whatever type is used for 64-bit integers.
-
-=back
-
-=head2 r
-
-=over 4
-
-=item C<randbits>
-
-From F<randfunc.U>:
-
-Indicates how many bits are produced by the function used to
-generate normalized random numbers.
-
-=item C<randfunc>
-
-From F<randfunc.U>:
-
-Indicates the name of the random number function to use.
-Values include drand48, random, and rand. In C programs,
-the C<Drand01> macro is defined to generate uniformly distributed
-random numbers over the range [0., 1.[ (see drand01 and nrand).
-
-=item C<random_r_proto>
-
-From F<d_random_r.U>:
-
-This variable encodes the prototype of random_r.
-It is zero if d_random_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_random_r
-is defined.
-
-=item C<randseedtype>
-
-From F<randfunc.U>:
-
-Indicates the type of the argument of the seedfunc.
-
-=item C<ranlib>
-
-From F<orderlib.U>:
-
-This variable is set to the pathname of the ranlib program, if it is
-needed to generate random libraries. Set to C<:> if ar can generate
-random libraries or if random libraries are not supported
-
-=item C<rd_nodata>
-
-From F<nblock_io.U>:
-
-This variable holds the return code from read() when no data is
-present. It should be -1, but some systems return 0 when C<O_NDELAY> is
-used, which is a shame because you cannot make the difference between
-no data and an F<EOF.>. Sigh!
-
-=item C<readdir64_r_proto>
-
-From F<d_readdir64_r.U>:
-
-This variable encodes the prototype of readdir64_r.
-It is zero if d_readdir64_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_readdir64_r
-is defined.
-
-=item C<readdir_r_proto>
-
-From F<d_readdir_r.U>:
-
-This variable encodes the prototype of readdir_r.
-It is zero if d_readdir_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_readdir_r
-is defined.
-
-=item C<revision>
-
-From F<patchlevel.U>:
-
-The value of revision comes from the F<patchlevel.h> file.
-In a version number such as 5.6.1, this is the C<5>.
-In F<patchlevel.h>, this is referred to as C<PERL_REVISION>.
-
-=item C<rm>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the rm program. After Configure runs,
-the value is reset to a plain C<rm> and is not useful.
-
-=item C<rm_try>
-
-From F<Unix.U>:
-
-This is a cleanup variable for try test programs.
-Internal Configure use only.
-
-=item C<rmail>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<run>
-
-From F<Cross.U>:
-
-This variable contains the command used by Configure
-to copy and execute a cross-compiled executable in the
-target host. Useful and available only during Perl build.
-Empty string '' if not cross-compiling.
-
-=item C<runnm>
-
-From F<usenm.U>:
-
-This variable contains C<true> or C<false> depending whether the
-nm extraction should be performed or not, according to the value
-of usenm and the flags on the Configure command line.
-
-=back
-
-=head2 s
-
-=over 4
-
-=item C<sched_yield>
-
-From F<d_pthread_y.U>:
-
-This variable defines the way to yield the execution
-of the current thread.
-
-=item C<scriptdir>
-
-From F<scriptdir.U>:
-
-This variable holds the name of the directory in which the user wants
-to put publicly scripts for the package in question. It is either
-the same directory as for binaries, or a special one that can be
-mounted across different architectures, like F</usr/share>. Programs
-must be prepared to deal with F<~name> expansion.
-
-=item C<scriptdirexp>
-
-From F<scriptdir.U>:
-
-This variable is the same as scriptdir, but is filename expanded
-at configuration time, for programs not wanting to bother with it.
-
-=item C<sed>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the sed program. After Configure runs,
-the value is reset to a plain C<sed> and is not useful.
-
-=item C<seedfunc>
-
-From F<randfunc.U>:
-
-Indicates the random number generating seed function.
-Values include srand48, srandom, and srand.
-
-=item C<selectminbits>
-
-From F<selectminbits.U>:
-
-This variable holds the minimum number of bits operated by select.
-That is, if you do select(n, ...), how many bits at least will be
-cleared in the masks if some activity is detected. Usually this
-is either n or 32*ceil(F<n/32>), especially many little-endians do
-the latter. This is only useful if you have select(), naturally.
-
-=item C<selecttype>
-
-From F<selecttype.U>:
-
-This variable holds the type used for the 2nd, 3rd, and 4th
-arguments to select. Usually, this is C<fd_set *>, if C<HAS_FD_SET>
-is defined, and C<int *> otherwise. This is only useful if you
-have select(), naturally.
-
-=item C<sendmail>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<setgrent_r_proto>
-
-From F<d_setgrent_r.U>:
-
-This variable encodes the prototype of setgrent_r.
-It is zero if d_setgrent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setgrent_r
-is defined.
-
-=item C<sethostent_r_proto>
-
-From F<d_sethostent_r.U>:
-
-This variable encodes the prototype of sethostent_r.
-It is zero if d_sethostent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_sethostent_r
-is defined.
-
-=item C<setlocale_r_proto>
-
-From F<d_setlocale_r.U>:
-
-This variable encodes the prototype of setlocale_r.
-It is zero if d_setlocale_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setlocale_r
-is defined.
-
-=item C<setnetent_r_proto>
-
-From F<d_setnetent_r.U>:
-
-This variable encodes the prototype of setnetent_r.
-It is zero if d_setnetent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setnetent_r
-is defined.
-
-=item C<setprotoent_r_proto>
-
-From F<d_setprotoent_r.U>:
-
-This variable encodes the prototype of setprotoent_r.
-It is zero if d_setprotoent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setprotoent_r
-is defined.
-
-=item C<setpwent_r_proto>
-
-From F<d_setpwent_r.U>:
-
-This variable encodes the prototype of setpwent_r.
-It is zero if d_setpwent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setpwent_r
-is defined.
-
-=item C<setservent_r_proto>
-
-From F<d_setservent_r.U>:
-
-This variable encodes the prototype of setservent_r.
-It is zero if d_setservent_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setservent_r
-is defined.
-
-=item C<sGMTIME_max>
-
-From F<time_size.U>:
-
-This variable defines the maximum value of the time_t offset that
-the system function gmtime () accepts
-
-=item C<sGMTIME_min>
-
-From F<time_size.U>:
-
-This variable defines the minimum value of the time_t offset that
-the system function gmtime () accepts
-
-=item C<sh>
-
-From F<sh.U>:
-
-This variable contains the full pathname of the shell used
-on this system to execute Bourne shell scripts. Usually, this will be
-F</bin/sh>, though it's possible that some systems will have F</bin/ksh>,
-F</bin/pdksh>, F</bin/ash>, F</bin/bash>, or even something such as
-D:F</bin/sh.exe>.
-This unit comes before F<Options.U>, so you can't set sh with a C<-D>
-option, though you can override this (and startsh)
-with C<-O -Dsh=F</bin/whatever> -Dstartsh=whatever>
-
-=item C<shar>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<sharpbang>
-
-From F<spitshell.U>:
-
-This variable contains the string #! if this system supports that
-construct.
-
-=item C<shmattype>
-
-From F<d_shmat.U>:
-
-This symbol contains the type of pointer returned by shmat().
-It can be C<void *> or C<char *>.
-
-=item C<shortsize>
-
-From F<intsize.U>:
-
-This variable contains the value of the C<SHORTSIZE> symbol which
-indicates to the C program how many bytes there are in a short.
-
-=item C<shrpenv>
-
-From F<libperl.U>:
-
-If the user builds a shared F<libperl.so>, then we need to tell the
-C<perl> executable where it will be able to find the installed F<libperl.so>.
-One way to do this on some systems is to set the environment variable
-C<LD_RUN_PATH> to the directory that will be the final location of the
-shared F<libperl.so>. The makefile can use this with something like
-$shrpenv $(C<CC>) -o perl F<perlmain.o> $libperl $libs
-Typical values are
-shrpenv="env C<LD_RUN_PATH>=F<$archlibexp/C<CORE>>"
-or
-shrpenv=''
-See the main perl F<Makefile.SH> for actual working usage.
-
-Alternatively, we might be able to use a command line option such
-as -R F<$archlibexp/C<CORE>> (Solaris) or -Wl,-rpath
-F<$archlibexp/C<CORE>> (Linux).
-
-=item C<shsharp>
-
-From F<spitshell.U>:
-
-This variable tells further Configure units whether your sh can
-handle # comments.
-
-=item C<sig_count>
-
-From F<sig_name.U>:
-
-This variable holds a number larger than the largest valid
-signal number. This is usually the same as the C<NSIG> macro.
-
-=item C<sig_name>
-
-From F<sig_name.U>:
-
-This variable holds the signal names, space separated. The leading
-C<SIG> in signal name is removed. A C<ZERO> is prepended to the list.
-This is currently not used, sig_name_init is used instead.
-
-=item C<sig_name_init>
-
-From F<sig_name.U>:
-
-This variable holds the signal names, enclosed in double quotes and
-separated by commas, suitable for use in the C<SIG_NAME> definition
-below. A C<ZERO> is prepended to the list, and the list is
-terminated with a plain 0. The leading C<SIG> in signal names
-is removed. See sig_num.
-
-=item C<sig_num>
-
-From F<sig_name.U>:
-
-This variable holds the signal numbers, space separated. A C<ZERO> is
-prepended to the list (corresponding to the fake C<SIGZERO>).
-Those numbers correspond to the value of the signal listed
-in the same place within the sig_name list.
-This is currently not used, sig_num_init is used instead.
-
-=item C<sig_num_init>
-
-From F<sig_name.U>:
-
-This variable holds the signal numbers, enclosed in double quotes and
-separated by commas, suitable for use in the C<SIG_NUM> definition
-below. A C<ZERO> is prepended to the list, and the list is
-terminated with a plain 0.
-
-=item C<sig_size>
-
-From F<sig_name.U>:
-
-This variable contains the number of elements of the sig_name
-and sig_num arrays.
-
-=item C<signal_t>
-
-From F<d_voidsig.U>:
-
-This variable holds the type of the signal handler (void or int).
-
-=item C<sitearch>
-
-From F<sitearch.U>:
-
-This variable contains the eventual value of the C<SITEARCH> symbol,
-which is the name of the private library for this package. It may
-have a F<~> on the front. It is up to the makefile to eventually create
-this directory while performing installation (with F<~> substitution).
-The standard distribution will put nothing in this directory.
-After perl has been installed, users may install their own local
-architecture-dependent modules in this directory with
-MakeMaker F<Makefile.PL>
-or equivalent. See C<INSTALL> for details.
-
-=item C<sitearchexp>
-
-From F<sitearch.U>:
-
-This variable is the F<~name> expanded version of sitearch, so that you
-may use it directly in Makefiles or shell scripts.
-
-=item C<sitebin>
-
-From F<sitebin.U>:
-
-This variable holds the name of the directory in which the user wants
-to put add-on publicly executable files for the package in question. It
-is most often a local directory such as F</usr/local/bin>. Programs using
-this variable must be prepared to deal with F<~name> substitution.
-The standard distribution will put nothing in this directory.
-After perl has been installed, users may install their own local
-executables in this directory with
-MakeMaker F<Makefile.PL>
-or equivalent. See C<INSTALL> for details.
-
-=item C<sitebinexp>
-
-From F<sitebin.U>:
-
-This is the same as the sitebin variable, but is filename expanded at
-configuration time, for use in your makefiles.
-
-=item C<sitehtml1dir>
-
-From F<sitehtml1dir.U>:
-
-This variable contains the name of the directory in which site-specific
-html source pages are to be put. It is the responsibility of the
-F<Makefile.SH> to get the value of this into the proper command.
-You must be prepared to do the F<~name> expansion yourself.
-The standard distribution will put nothing in this directory.
-After perl has been installed, users may install their own local
-html pages in this directory with
-MakeMaker F<Makefile.PL>
-or equivalent. See C<INSTALL> for details.
-
-=item C<sitehtml1direxp>
-
-From F<sitehtml1dir.U>:
-
-This variable is the same as the sitehtml1dir variable, but is filename
-expanded at configuration time, for convenient use in makefiles.
-
-=item C<sitehtml3dir>
-
-From F<sitehtml3dir.U>:
-
-This variable contains the name of the directory in which site-specific
-library html source pages are to be put. It is the responsibility of the
-F<Makefile.SH> to get the value of this into the proper command.
-You must be prepared to do the F<~name> expansion yourself.
-The standard distribution will put nothing in this directory.
-After perl has been installed, users may install their own local
-library html pages in this directory with
-MakeMaker F<Makefile.PL>
-or equivalent. See C<INSTALL> for details.
-
-=item C<sitehtml3direxp>
-
-From F<sitehtml3dir.U>:
-
-This variable is the same as the sitehtml3dir variable, but is filename
-expanded at configuration time, for convenient use in makefiles.
-
-=item C<sitelib>
-
-From F<sitelib.U>:
-
-This variable contains the eventual value of the C<SITELIB> symbol,
-which is the name of the private library for this package. It may
-have a F<~> on the front. It is up to the makefile to eventually create
-this directory while performing installation (with F<~> substitution).
-The standard distribution will put nothing in this directory.
-After perl has been installed, users may install their own local
-architecture-independent modules in this directory with
-MakeMaker F<Makefile.PL>
-or equivalent. See C<INSTALL> for details.
-
-=item C<sitelib_stem>
-
-From F<sitelib.U>:
-
-This variable is $sitelibexp with any trailing version-specific component
-removed. The elements in inc_version_list (F<inc_version_list.U>) can
-be tacked onto this variable to generate a list of directories to search.
-
-=item C<sitelibexp>
-
-From F<sitelib.U>:
-
-This variable is the F<~name> expanded version of sitelib, so that you
-may use it directly in Makefiles or shell scripts.
-
-=item C<siteman1dir>
-
-From F<siteman1dir.U>:
-
-This variable contains the name of the directory in which site-specific
-manual source pages are to be put. It is the responsibility of the
-F<Makefile.SH> to get the value of this into the proper command.
-You must be prepared to do the F<~name> expansion yourself.
-The standard distribution will put nothing in this directory.
-After perl has been installed, users may install their own local
-man1 pages in this directory with
-MakeMaker F<Makefile.PL>
-or equivalent. See C<INSTALL> for details.
-
-=item C<siteman1direxp>
-
-From F<siteman1dir.U>:
-
-This variable is the same as the siteman1dir variable, but is filename
-expanded at configuration time, for convenient use in makefiles.
-
-=item C<siteman3dir>
-
-From F<siteman3dir.U>:
-
-This variable contains the name of the directory in which site-specific
-library man source pages are to be put. It is the responsibility of the
-F<Makefile.SH> to get the value of this into the proper command.
-You must be prepared to do the F<~name> expansion yourself.
-The standard distribution will put nothing in this directory.
-After perl has been installed, users may install their own local
-man3 pages in this directory with
-MakeMaker F<Makefile.PL>
-or equivalent. See C<INSTALL> for details.
-
-=item C<siteman3direxp>
-
-From F<siteman3dir.U>:
-
-This variable is the same as the siteman3dir variable, but is filename
-expanded at configuration time, for convenient use in makefiles.
-
-=item C<siteprefix>
-
-From F<siteprefix.U>:
-
-This variable holds the full absolute path of the directory below
-which the user will install add-on packages.
-See C<INSTALL> for usage and examples.
-
-=item C<siteprefixexp>
-
-From F<siteprefix.U>:
-
-This variable holds the full absolute path of the directory below
-which the user will install add-on packages. Derived from siteprefix.
-
-=item C<sitescript>
-
-From F<sitescript.U>:
-
-This variable holds the name of the directory in which the user wants
-to put add-on publicly executable files for the package in question. It
-is most often a local directory such as F</usr/local/bin>. Programs using
-this variable must be prepared to deal with F<~name> substitution.
-The standard distribution will put nothing in this directory.
-After perl has been installed, users may install their own local
-scripts in this directory with
-MakeMaker F<Makefile.PL>
-or equivalent. See C<INSTALL> for details.
-
-=item C<sitescriptexp>
-
-From F<sitescript.U>:
-
-This is the same as the sitescript variable, but is filename expanded at
-configuration time, for use in your makefiles.
-
-=item C<sizesize>
-
-From F<sizesize.U>:
-
-This variable contains the size of a sizetype in bytes.
-
-=item C<sizetype>
-
-From F<sizetype.U>:
-
-This variable defines sizetype to be something like size_t,
-unsigned long, or whatever type is used to declare length
-parameters for string functions.
-
-=item C<sleep>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<sLOCALTIME_max>
-
-From F<time_size.U>:
-
-This variable defines the maximum value of the time_t offset that
-the system function localtime () accepts
-
-=item C<sLOCALTIME_min>
-
-From F<time_size.U>:
-
-This variable defines the minimum value of the time_t offset that
-the system function localtime () accepts
-
-=item C<smail>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<so>
-
-From F<so.U>:
-
-This variable holds the extension used to identify shared libraries
-(also known as shared objects) on the system. Usually set to C<so>.
-
-=item C<sockethdr>
-
-From F<d_socket.U>:
-
-This variable has any cpp C<-I> flags needed for socket support.
-
-=item C<socketlib>
-
-From F<d_socket.U>:
-
-This variable has the names of any libraries needed for socket support.
-
-=item C<socksizetype>
-
-From F<socksizetype.U>:
-
-This variable holds the type used for the size argument
-for various socket calls like accept. Usual values include
-socklen_t, size_t, and int.
-
-=item C<sort>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the sort program. After Configure runs,
-the value is reset to a plain C<sort> and is not useful.
-
-=item C<spackage>
-
-From F<package.U>:
-
-This variable contains the name of the package being constructed,
-with the first letter uppercased, F<i.e>. suitable for starting
-sentences.
-
-=item C<spitshell>
-
-From F<spitshell.U>:
-
-This variable contains the command necessary to spit out a runnable
-shell on this system. It is either cat or a grep C<-v> for # comments.
-
-=item C<sPRId64>
-
-From F<quadfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format 64-bit decimal numbers (format C<d>) for output.
-
-=item C<sPRIeldbl>
-
-From F<longdblfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format long doubles (format C<e>) for output.
-
-=item C<sPRIEUldbl>
-
-From F<longdblfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format long doubles (format C<E>) for output.
-The C<U> in the name is to separate this from sPRIeldbl so that even
-case-blind systems can see the difference.
-
-=item C<sPRIfldbl>
-
-From F<longdblfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format long doubles (format C<f>) for output.
-
-=item C<sPRIFUldbl>
-
-From F<longdblfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format long doubles (format C<F>) for output.
-The C<U> in the name is to separate this from sPRIfldbl so that even
-case-blind systems can see the difference.
-
-=item C<sPRIgldbl>
-
-From F<longdblfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format long doubles (format C<g>) for output.
-
-=item C<sPRIGUldbl>
-
-From F<longdblfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format long doubles (format C<G>) for output.
-The C<U> in the name is to separate this from sPRIgldbl so that even
-case-blind systems can see the difference.
-
-=item C<sPRIi64>
-
-From F<quadfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format 64-bit decimal numbers (format C<i>) for output.
-
-=item C<sPRIo64>
-
-From F<quadfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format 64-bit octal numbers (format C<o>) for output.
-
-=item C<sPRIu64>
-
-From F<quadfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format 64-bit unsigned decimal numbers (format C<u>) for output.
-
-=item C<sPRIx64>
-
-From F<quadfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format 64-bit hexadecimal numbers (format C<x>) for output.
-
-=item C<sPRIXU64>
-
-From F<quadfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format 64-bit hExADECimAl numbers (format C<X>) for output.
-The C<U> in the name is to separate this from sPRIx64 so that even
-case-blind systems can see the difference.
-
-=item C<srand48_r_proto>
-
-From F<d_srand48_r.U>:
-
-This variable encodes the prototype of srand48_r.
-It is zero if d_srand48_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_srand48_r
-is defined.
-
-=item C<srandom_r_proto>
-
-From F<d_srandom_r.U>:
-
-This variable encodes the prototype of srandom_r.
-It is zero if d_srandom_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_srandom_r
-is defined.
-
-=item C<src>
-
-From F<src.U>:
-
-This variable holds the (possibly relative) path of the package source.
-It is up to the Makefile to use this variable and set C<VPATH> accordingly
-to find the sources remotely. Use $pkgsrc to have an absolute path.
-
-=item C<sSCNfldbl>
-
-From F<longdblfio.U>:
-
-This variable, if defined, contains the string used by stdio to
-format long doubles (format C<f>) for input.
-
-=item C<ssizetype>
-
-From F<ssizetype.U>:
-
-This variable defines ssizetype to be something like ssize_t,
-long or int. It is used by functions that return a count
-of bytes or an error condition. It must be a signed type.
-We will pick a type such that sizeof(SSize_t) == sizeof(Size_t).
-
-=item C<st_ino_sign>
-
-From F<st_ino_def.U>:
-
-This variable contains the signedness of struct stat's st_ino.
-1 for unsigned, -1 for signed.
-
-=item C<st_ino_size>
-
-From F<st_ino_def.U>:
-
-This variable contains the size of struct stat's st_ino in bytes.
-
-=item C<startperl>
-
-From F<startperl.U>:
-
-This variable contains the string to put on the front of a perl
-script to make sure (hopefully) that it runs with perl and not some
-shell. Of course, that leading line must be followed by the classical
-perl idiom:
-eval 'exec perl -S $0 ${1+C<$@>}'
-if $running_under_some_shell;
-to guarantee perl startup should the shell execute the script. Note
-that this magic incantation is not understood by csh.
-
-=item C<startsh>
-
-From F<startsh.U>:
-
-This variable contains the string to put on the front of a shell
-script to make sure (hopefully) that it runs with sh and not some
-other shell.
-
-=item C<static_ext>
-
-From F<Extensions.U>:
-
-This variable holds a list of C<XS> extension files we want to
-link statically into the package. It is used by Makefile.
-
-=item C<stdchar>
-
-From F<stdchar.U>:
-
-This variable conditionally defines C<STDCHAR> to be the type of char
-used in F<stdio.h>. It has the values "unsigned char" or C<char>.
-
-=item C<stdio_base>
-
-From F<d_stdstdio.U>:
-
-This variable defines how, given a C<FILE> pointer, fp, to access the
-_base field (or equivalent) of F<stdio.h>'s C<FILE> structure. This will
-be used to define the macro FILE_base(fp).
-
-=item C<stdio_bufsiz>
-
-From F<d_stdstdio.U>:
-
-This variable defines how, given a C<FILE> pointer, fp, to determine
-the number of bytes store in the I/O buffer pointer to by the
-_base field (or equivalent) of F<stdio.h>'s C<FILE> structure. This will
-be used to define the macro FILE_bufsiz(fp).
-
-=item C<stdio_cnt>
-
-From F<d_stdstdio.U>:
-
-This variable defines how, given a C<FILE> pointer, fp, to access the
-_cnt field (or equivalent) of F<stdio.h>'s C<FILE> structure. This will
-be used to define the macro FILE_cnt(fp).
-
-=item C<stdio_filbuf>
-
-From F<d_stdstdio.U>:
-
-This variable defines how, given a C<FILE> pointer, fp, to tell
-stdio to refill its internal buffers (?). This will
-be used to define the macro FILE_filbuf(fp).
-
-=item C<stdio_ptr>
-
-From F<d_stdstdio.U>:
-
-This variable defines how, given a C<FILE> pointer, fp, to access the
-_ptr field (or equivalent) of F<stdio.h>'s C<FILE> structure. This will
-be used to define the macro FILE_ptr(fp).
-
-=item C<stdio_stream_array>
-
-From F<stdio_streams.U>:
-
-This variable tells the name of the array holding the stdio streams.
-Usual values include _iob, __iob, and __sF.
-
-=item C<strerror_r_proto>
-
-From F<d_strerror_r.U>:
-
-This variable encodes the prototype of strerror_r.
-It is zero if d_strerror_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_strerror_r
-is defined.
-
-=item C<submit>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<subversion>
-
-From F<patchlevel.U>:
-
-The subversion level of this package.
-The value of subversion comes from the F<patchlevel.h> file.
-In a version number such as 5.6.1, this is the C<1>.
-In F<patchlevel.h>, this is referred to as C<PERL_SUBVERSION>.
-This is unique to perl.
-
-=item C<sysman>
-
-From F<sysman.U>:
-
-This variable holds the place where the manual is located on this
-system. It is not the place where the user wants to put his manual
-pages. Rather it is the place where Configure may look to find manual
-for unix commands (section 1 of the manual usually). See mansrc.
-
-=item C<sysroot>
-
-From F<Sysroot.U>:
-
-This variable is empty unless supplied by the Configure user.
-It can contain a path to an alternative root directory, under which
-headers and libraries for the compilation target can be found. This
-is generally used when cross-compiling using a gcc-like compiler.
-
-=back
-
-=head2 t
-
-=over 4
-
-=item C<tail>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<tar>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<targetarch>
-
-From F<Cross.U>:
-
-If cross-compiling, this variable contains the target architecture.
-If not, this will be empty.
-
-=item C<targetdir>
-
-From F<Cross.U>:
-
-This variable contains a path that will be created on the target
-host using targetmkdir, and then used to copy the cross-compiled
-executables to. Defaults to F</tmp> if not set.
-
-=item C<targetenv>
-
-From F<Cross.U>:
-
-If cross-compiling, this variable can be used to modify the
-environment on the target system.
-However, how and where it's used, and even if it's used at all, is
-entirely dependent on both the transport mechanism (targetrun) and
-what the target system is. Unless the relevant documentation says
-otherwise, it is genereally not useful.
-
-=item C<targethost>
-
-From F<Cross.U>:
-
-This variable contains the name of a separate host machine that
-can be used to run compiled test programs and perl tests on.
-Set to empty string if not in use.
-
-=item C<targetmkdir>
-
-From F<Cross.U>:
-
-This variable contains the command used by Configure to create a
-new directory on the target host.
-
-=item C<targetport>
-
-From F<Cross.U>:
-
-This variable contains the number of a network port to be used to
-connect to the host in targethost, if unset defaults to 22 for ssh.
-
-=item C<targetsh>
-
-From F<sh.U>:
-
-If cross-compiling, this variable contains the location of sh on the
-target system.
-If not, this will be the same as $sh.
-
-=item C<tbl>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<tee>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<test>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the test program. After Configure runs,
-the value is reset to a plain C<test> and is not useful.
-
-=item C<timeincl>
-
-From F<i_time.U>:
-
-This variable holds the full path of the included time header(s).
-
-=item C<timetype>
-
-From F<d_time.U>:
-
-This variable holds the type returned by time(). It can be long,
-or time_t on C<BSD> sites (in which case <sys/types.h> should be
-included). Anyway, the type Time_t should be used.
-
-=item C<tmpnam_r_proto>
-
-From F<d_tmpnam_r.U>:
-
-This variable encodes the prototype of tmpnam_r.
-It is zero if d_tmpnam_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_tmpnam_r
-is defined.
-
-=item C<to>
-
-From F<Cross.U>:
-
-This variable contains the command used by Configure
-to copy to from the target host. Useful and available
-only during Perl build.
-The string C<:> if not cross-compiling.
-
-=item C<touch>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the touch program. After Configure runs,
-the value is reset to a plain C<touch> and is not useful.
-
-=item C<tr>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the tr program. After Configure runs,
-the value is reset to a plain C<tr> and is not useful.
-
-=item C<trnl>
-
-From F<trnl.U>:
-
-This variable contains the value to be passed to the tr(1)
-command to transliterate a newline. Typical values are
-C<\012> and C<\n>. This is needed for C<EBCDIC> systems where
-newline is not necessarily C<\012>.
-
-=item C<troff>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<ttyname_r_proto>
-
-From F<d_ttyname_r.U>:
-
-This variable encodes the prototype of ttyname_r.
-It is zero if d_ttyname_r is undef, and one of the
-C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_ttyname_r
-is defined.
-
-=back
-
-=head2 u
-
-=over 4
-
-=item C<u16size>
-
-From F<perlxv.U>:
-
-This variable is the size of an U16 in bytes.
-
-=item C<u16type>
-
-From F<perlxv.U>:
-
-This variable contains the C type used for Perl's U16.
-
-=item C<u32size>
-
-From F<perlxv.U>:
-
-This variable is the size of an U32 in bytes.
-
-=item C<u32type>
-
-From F<perlxv.U>:
-
-This variable contains the C type used for Perl's U32.
-
-=item C<u64size>
-
-From F<perlxv.U>:
-
-This variable is the size of an U64 in bytes.
-
-=item C<u64type>
-
-From F<perlxv.U>:
-
-This variable contains the C type used for Perl's U64.
-
-=item C<u8size>
-
-From F<perlxv.U>:
-
-This variable is the size of an U8 in bytes.
-
-=item C<u8type>
-
-From F<perlxv.U>:
-
-This variable contains the C type used for Perl's U8.
-
-=item C<uidformat>
-
-From F<uidf.U>:
-
-This variable contains the format string used for printing a Uid_t.
-
-=item C<uidsign>
-
-From F<uidsign.U>:
-
-This variable contains the signedness of a uidtype.
-1 for unsigned, -1 for signed.
-
-=item C<uidsize>
-
-From F<uidsize.U>:
-
-This variable contains the size of a uidtype in bytes.
-
-=item C<uidtype>
-
-From F<uidtype.U>:
-
-This variable defines Uid_t to be something like uid_t, int,
-ushort, or whatever type is used to declare user ids in the kernel.
-
-=item C<uname>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the uname program. After Configure runs,
-the value is reset to a plain C<uname> and is not useful.
-
-=item C<uniq>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the uniq program. After Configure runs,
-the value is reset to a plain C<uniq> and is not useful.
-
-=item C<uquadtype>
-
-From F<quadtype.U>:
-
-This variable defines Uquad_t to be something like unsigned long,
-unsigned int, unsigned long long, uint64_t, or whatever type is
-used for 64-bit integers.
-
-=item C<use5005threads>
-
-From F<usethreads.U>:
-
-This variable conditionally defines the USE_5005THREADS symbol,
-and indicates that Perl should be built to use the 5.005-based
-threading implementation. Only valid up to 5.8.x.
-
-=item C<use64bitall>
-
-From F<use64bits.U>:
-
-This variable conditionally defines the USE_64_BIT_ALL symbol,
-and indicates that 64-bit integer types should be used
-when available. The maximal possible
-64-bitness is employed: LP64 or ILP64, meaning that you will
-be able to use more than 2 gigabytes of memory. This mode is
-even more binary incompatible than USE_64_BIT_INT. You may not
-be able to run the resulting executable in a 32-bit C<CPU> at all or
-you may need at least to reboot your C<OS> to 64-bit mode.
-
-=item C<use64bitint>
-
-From F<use64bits.U>:
-
-This variable conditionally defines the USE_64_BIT_INT symbol,
-and indicates that 64-bit integer types should be used
-when available. The minimal possible 64-bitness
-is employed, just enough to get 64-bit integers into Perl.
-This may mean using for example "long longs", while your memory
-may still be limited to 2 gigabytes.
-
-=item C<usecbacktrace>
-
-From F<usebacktrace.U>:
-
-This variable indicates whether we are compiling with backtrace
-support.
-
-=item C<usecrosscompile>
-
-From F<Cross.U>:
-
-This variable conditionally defines the C<USE_CROSS_COMPILE> symbol,
-and indicates that Perl has been cross-compiled.
-
-=item C<usedevel>
-
-From F<Devel.U>:
-
-This variable indicates that Perl was configured with development
-features enabled. This should not be done for production builds.
-
-=item C<usedl>
-
-From F<dlsrc.U>:
-
-This variable indicates if the system supports dynamic
-loading of some sort. See also dlsrc and dlobj.
-
-=item C<usedtrace>
-
-From F<usedtrace.U>:
-
-This variable indicates whether we are compiling with dtrace
-support. See also dtrace.
-
-=item C<usefaststdio>
-
-From F<usefaststdio.U>:
-
-This variable conditionally defines the C<USE_FAST_STDIO> symbol,
-and indicates that Perl should be built to use C<fast stdio>.
-Defaults to define in Perls 5.8 and earlier, to undef later.
-
-=item C<useithreads>
-
-From F<usethreads.U>:
-
-This variable conditionally defines the C<USE_ITHREADS> symbol,
-and indicates that Perl should be built to use the interpreter-based
-threading implementation.
-
-=item C<usekernprocpathname>
-
-From F<usekernprocpathname.U>:
-
-This variable, indicates that we can use sysctl with
-C<KERN_PROC_PATHNAME> to get a full path for the executable, and hence
-convert $^X to an absolute path.
-
-=item C<uselanginfo>
-
-From F<Extensions.U>:
-
-This variable holds either C<true> or C<false> to indicate
-whether the I18N::Langinfo extension should be used. The sole
-use for this currently is to allow an easy mechanism for users to skip
-this extension from the Configure command line.
-
-=item C<uselargefiles>
-
-From F<uselfs.U>:
-
-This variable conditionally defines the C<USE_LARGE_FILES> symbol,
-and indicates that large file interfaces should be used when
-available.
-
-=item C<uselongdouble>
-
-From F<uselongdbl.U>:
-
-This variable conditionally defines the C<USE_LONG_DOUBLE> symbol,
-and indicates that long doubles should be used when available.
-
-=item C<usemallocwrap>
-
-From F<mallocsrc.U>:
-
-This variable contains y if we are wrapping malloc to prevent
-integer overflow during size calculations.
-
-=item C<usemorebits>
-
-From F<usemorebits.U>:
-
-This variable conditionally defines the C<USE_MORE_BITS> symbol,
-and indicates that explicit 64-bit interfaces and long doubles
-should be used when available.
-
-=item C<usemultiplicity>
-
-From F<usemultiplicity.U>:
-
-This variable conditionally defines the C<MULTIPLICITY> symbol,
-and indicates that Perl should be built to use multiplicity.
-
-=item C<usemymalloc>
-
-From F<mallocsrc.U>:
-
-This variable contains y if the malloc that comes with this package
-is desired over the system's version of malloc. People often include
-special versions of malloc for efficiency, but such versions are often
-less portable. See also mallocsrc and mallocobj.
-If this is C<y>, then -lmalloc is removed from $libs.
-
-=item C<usenm>
-
-From F<usenm.U>:
-
-This variable contains C<true> or C<false> depending whether the
-nm extraction is wanted or not.
-
-=item C<usensgetexecutablepath>
-
-From F<usensgetexecutablepath.U>:
-
-This symbol, if defined, indicates that we can use _NSGetExecutablePath
-and realpath to get a full path for the executable, and hence convert
-$^X to an absolute path.
-
-=item C<useopcode>
-
-From F<Extensions.U>:
-
-This variable holds either C<true> or C<false> to indicate
-whether the Opcode extension should be used. The sole
-use for this currently is to allow an easy mechanism
-for users to skip the Opcode extension from the Configure
-command line.
-
-=item C<useperlio>
-
-From F<useperlio.U>:
-
-This variable conditionally defines the C<USE_PERLIO> symbol,
-and indicates that the PerlIO abstraction should be
-used throughout.
-
-=item C<useposix>
-
-From F<Extensions.U>:
-
-This variable holds either C<true> or C<false> to indicate
-whether the C<POSIX> extension should be used. The sole
-use for this currently is to allow an easy mechanism
-for hints files to indicate that C<POSIX> will not compile
-on a particular system.
-
-=item C<usequadmath>
-
-From F<usequadmath.U>:
-
-This variable conditionally defines the C<USE_QUADMATH> symbol,
-and indicates that the quadmath library __float128 long doubles
-should be used when available.
-
-=item C<usereentrant>
-
-From F<usethreads.U>:
-
-This variable conditionally defines the C<USE_REENTRANT_API> symbol,
-which indicates that the thread code may try to use the various
-_r versions of library functions. This is only potentially
-meaningful if usethreads is set and is very experimental, it is
-not even prompted for.
-
-=item C<userelocatableinc>
-
-From F<bin.U>:
-
-This variable is set to true to indicate that perl should relocate
-@C<INC> entries at runtime based on the path to the perl binary.
-Any @C<INC> paths starting F<.../> are relocated relative to the directory
-containing the perl binary, and a logical cleanup of the path is then
-made around the join point (removing F<dir/../> pairs)
-
-=item C<useshrplib>
-
-From F<libperl.U>:
-
-This variable is set to C<true> if the user wishes
-to build a shared libperl, and C<false> otherwise.
-
-=item C<usesitecustomize>
-
-From F<d_sitecustomize.U>:
-
-This variable is set to true when the user requires a mechanism that
-allows the sysadmin to add entries to @C<INC> at runtime. This variable
-being set, makes perl run F<$sitelib/sitecustomize.pl> at startup.
-
-=item C<usesocks>
-
-From F<usesocks.U>:
-
-This variable conditionally defines the C<USE_SOCKS> symbol,
-and indicates that Perl should be built to use C<SOCKS>.
-
-=item C<usethreads>
-
-From F<usethreads.U>:
-
-This variable conditionally defines the C<USE_THREADS> symbol,
-and indicates that Perl should be built to use threads.
-
-=item C<usevendorprefix>
-
-From F<vendorprefix.U>:
-
-This variable tells whether the vendorprefix
-and consequently other vendor* paths are in use.
-
-=item C<useversionedarchname>
-
-From F<archname.U>:
-
-This variable indicates whether to include the $api_versionstring
-as a component of the $archname.
-
-=item C<usevfork>
-
-From F<d_vfork.U>:
-
-This variable is set to true when the user accepts to use vfork.
-It is set to false when no vfork is available or when the user
-explicitly requests not to use vfork.
-
-=item C<usrinc>
-
-From F<usrinc.U>:
-
-This variable holds the path of the include files, which is
-usually F</usr/include>. It is mainly used by other Configure units.
-
-=item C<uuname>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<uvoformat>
-
-From F<perlxvf.U>:
-
-This variable contains the format string used for printing
-a Perl C<UV> as an unsigned octal integer.
-
-=item C<uvsize>
-
-From F<perlxv.U>:
-
-This variable is the size of a C<UV> in bytes.
-
-=item C<uvtype>
-
-From F<perlxv.U>:
-
-This variable contains the C type used for Perl's C<UV>.
-
-=item C<uvuformat>
-
-From F<perlxvf.U>:
-
-This variable contains the format string used for printing
-a Perl C<UV> as an unsigned decimal integer.
-
-=item C<uvxformat>
-
-From F<perlxvf.U>:
-
-This variable contains the format string used for printing
-a Perl C<UV> as an unsigned hexadecimal integer in lowercase abcdef.
-
-=item C<uvXUformat>
-
-From F<perlxvf.U>:
-
-This variable contains the format string used for printing
-a Perl C<UV> as an unsigned hexadecimal integer in uppercase C<ABCDEF>.
-
-=back
-
-=head2 v
-
-=over 4
-
-=item C<vendorarch>
-
-From F<vendorarch.U>:
-
-This variable contains the value of the C<PERL_VENDORARCH> symbol.
-It may have a F<~> on the front.
-The standard distribution will put nothing in this directory.
-Vendors who distribute perl may wish to place their own
-architecture-dependent modules and extensions in this directory with
-MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor
-or equivalent. See C<INSTALL> for details.
-
-=item C<vendorarchexp>
-
-From F<vendorarch.U>:
-
-This variable is the F<~name> expanded version of vendorarch, so that you
-may use it directly in Makefiles or shell scripts.
-
-=item C<vendorbin>
-
-From F<vendorbin.U>:
-
-This variable contains the eventual value of the C<VENDORBIN> symbol.
-It may have a F<~> on the front.
-The standard distribution will put nothing in this directory.
-Vendors who distribute perl may wish to place additional
-binaries in this directory with
-MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor
-or equivalent. See C<INSTALL> for details.
-
-=item C<vendorbinexp>
-
-From F<vendorbin.U>:
-
-This variable is the F<~name> expanded version of vendorbin, so that you
-may use it directly in Makefiles or shell scripts.
-
-=item C<vendorhtml1dir>
-
-From F<vendorhtml1dir.U>:
-
-This variable contains the name of the directory for html
-pages. It may have a F<~> on the front.
-The standard distribution will put nothing in this directory.
-Vendors who distribute perl may wish to place their own
-html pages in this directory with
-MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor
-or equivalent. See C<INSTALL> for details.
-
-=item C<vendorhtml1direxp>
-
-From F<vendorhtml1dir.U>:
-
-This variable is the F<~name> expanded version of vendorhtml1dir, so that you
-may use it directly in Makefiles or shell scripts.
-
-=item C<vendorhtml3dir>
-
-From F<vendorhtml3dir.U>:
-
-This variable contains the name of the directory for html
-library pages. It may have a F<~> on the front.
-The standard distribution will put nothing in this directory.
-Vendors who distribute perl may wish to place their own
-html pages for modules and extensions in this directory with
-MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor
-or equivalent. See C<INSTALL> for details.
-
-=item C<vendorhtml3direxp>
-
-From F<vendorhtml3dir.U>:
-
-This variable is the F<~name> expanded version of vendorhtml3dir, so that you
-may use it directly in Makefiles or shell scripts.
-
-=item C<vendorlib>
-
-From F<vendorlib.U>:
-
-This variable contains the eventual value of the C<VENDORLIB> symbol,
-which is the name of the private library for this package.
-The standard distribution will put nothing in this directory.
-Vendors who distribute perl may wish to place their own
-modules in this directory with
-MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor
-or equivalent. See C<INSTALL> for details.
-
-=item C<vendorlib_stem>
-
-From F<vendorlib.U>:
-
-This variable is $vendorlibexp with any trailing version-specific component
-removed. The elements in inc_version_list (F<inc_version_list.U>) can
-be tacked onto this variable to generate a list of directories to search.
-
-=item C<vendorlibexp>
-
-From F<vendorlib.U>:
-
-This variable is the F<~name> expanded version of vendorlib, so that you
-may use it directly in Makefiles or shell scripts.
-
-=item C<vendorman1dir>
-
-From F<vendorman1dir.U>:
-
-This variable contains the name of the directory for man1
-pages. It may have a F<~> on the front.
-The standard distribution will put nothing in this directory.
-Vendors who distribute perl may wish to place their own
-man1 pages in this directory with
-MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor
-or equivalent. See C<INSTALL> for details.
-
-=item C<vendorman1direxp>
-
-From F<vendorman1dir.U>:
-
-This variable is the F<~name> expanded version of vendorman1dir, so that you
-may use it directly in Makefiles or shell scripts.
-
-=item C<vendorman3dir>
-
-From F<vendorman3dir.U>:
-
-This variable contains the name of the directory for man3
-pages. It may have a F<~> on the front.
-The standard distribution will put nothing in this directory.
-Vendors who distribute perl may wish to place their own
-man3 pages in this directory with
-MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor
-or equivalent. See C<INSTALL> for details.
-
-=item C<vendorman3direxp>
-
-From F<vendorman3dir.U>:
-
-This variable is the F<~name> expanded version of vendorman3dir, so that you
-may use it directly in Makefiles or shell scripts.
-
-=item C<vendorprefix>
-
-From F<vendorprefix.U>:
-
-This variable holds the full absolute path of the directory below
-which the vendor will install add-on packages.
-See C<INSTALL> for usage and examples.
-
-=item C<vendorprefixexp>
-
-From F<vendorprefix.U>:
-
-This variable holds the full absolute path of the directory below
-which the vendor will install add-on packages. Derived from vendorprefix.
-
-=item C<vendorscript>
-
-From F<vendorscript.U>:
-
-This variable contains the eventual value of the C<VENDORSCRIPT> symbol.
-It may have a F<~> on the front.
-The standard distribution will put nothing in this directory.
-Vendors who distribute perl may wish to place additional
-executable scripts in this directory with
-MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor
-or equivalent. See C<INSTALL> for details.
-
-=item C<vendorscriptexp>
-
-From F<vendorscript.U>:
-
-This variable is the F<~name> expanded version of vendorscript, so that you
-may use it directly in Makefiles or shell scripts.
-
-=item C<version>
-
-From F<patchlevel.U>:
-
-The full version number of this package, such as 5.6.1 (or 5_6_1).
-This combines revision, patchlevel, and subversion to get the
-full version number, including any possible subversions.
-This is suitable for use as a directory name, and hence is
-filesystem dependent.
-
-=item C<version_patchlevel_string>
-
-From F<patchlevel.U>:
-
-This is a string combining version, subversion and
-perl_patchlevel (if perl_patchlevel is non-zero).
-It is typically something like
-'version 7 subversion 1' or
-'version 7 subversion 1 patchlevel 11224'
-It is computed here to avoid duplication of code in F<myconfig.SH>
-and F<lib/Config.pm>.
-
-=item C<versiononly>
-
-From F<versiononly.U>:
-
-If set, this symbol indicates that only the version-specific
-components of a perl installation should be installed.
-This may be useful for making a test installation of a new
-version without disturbing the existing installation.
-Setting versiononly is equivalent to setting installperl's -v option.
-In particular, the non-versioned scripts and programs such as
-a2p, c2ph, h2xs, pod2*, and perldoc are not installed
-(see C<INSTALL> for a more complete list). Nor are the man
-pages installed.
-Usually, this is undef.
-
-=item C<vi>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=back
-
-=head2 x
-
-=over 4
-
-=item C<xlibpth>
-
-From F<libpth.U>:
-
-This variable holds extra path (space-separated) used to find
-libraries on this platform, for example C<CPU>-specific libraries
-(on multi-C<CPU> platforms) may be listed here.
-
-=back
-
-=head2 y
-
-=over 4
-
-=item C<yacc>
-
-From F<yacc.U>:
-
-This variable holds the name of the compiler compiler we
-want to use in the Makefile. It can be yacc, byacc, or bison -y.
-
-=item C<yaccflags>
-
-From F<yacc.U>:
-
-This variable contains any additional yacc flags desired by the
-user. It is up to the Makefile to use this.
-
-=back
-
-=head2 z
-
-=over 4
-
-=item C<zcat>
-
-From F<Loc.U>:
-
-This variable is defined but not used by Configure.
-The value is the empty string and is not useful.
-
-=item C<zip>
-
-From F<Loc.U>:
-
-This variable is used internally by Configure to determine the
-full pathname (if any) of the zip program. After Configure runs,
-the value is reset to a plain C<zip> and is not useful.
-
-
-=back
-
-=head1 GIT DATA
-
-Information on the git commit from which the current perl binary was compiled
-can be found in the variable C<$Config::Git_Data>. The variable is a
-structured string that looks something like this:
-
- git_commit_id='ea0c2dbd5f5ac6845ecc7ec6696415bf8e27bd52'
- git_describe='GitLive-blead-1076-gea0c2db'
- git_branch='smartmatch'
- git_uncommitted_changes=''
- git_commit_id_title='Commit id:'
- git_commit_date='2009-05-09 17:47:31 +0200'
-
-Its format is not guaranteed not to change over time.
-
-=head1 NOTE
-
-This module contains a good example of how to use tie to implement a
-cache and an example of how to make a tied variable readonly to those
-outside of it.
-
-=cut
-
+=head1 NAME + +=for comment Generated by configpm. Any changes made here will be lost! + +Config - access Perl configuration information + +=head1 SYNOPSIS + + use Config; + if ($Config{usethreads}) { + print "has thread support\n" + } + + use Config qw(myconfig config_sh config_vars config_re); + + print myconfig(); + + print config_sh(); + + print config_re(); + + config_vars(qw(osname archname)); + + +=head1 DESCRIPTION + +The Config module contains all the information that was available to +the C<Configure> program at Perl build time (over 900 values). + +Shell variables from the F<config.sh> file (written by Configure) are +stored in the readonly-variable C<%Config>, indexed by their names. + +Values stored in config.sh as 'undef' are returned as undefined +values. The perl C<exists> function can be used to check if a +named variable exists. + +For a description of the variables, please have a look at the +Glossary file, as written in the Porting folder, or use the url: +https://github.com/Perl/perl5/blob/blead/Porting/Glossary + +=over 4 + +=item myconfig() + +Returns a textual summary of the major perl configuration values. +See also C<-V> in L<perlrun/Command Switches>. + +=item config_sh() + +Returns the entire perl configuration information in the form of the +original config.sh shell variable assignment script. + +=item config_re($regex) + +Like config_sh() but returns, as a list, only the config entries who's +names match the $regex. + +=item config_vars(@names) + +Prints to STDOUT the values of the named configuration variable. Each is +printed on a separate line in the form: + + name='value'; + +Names which are unknown are output as C<name='UNKNOWN';>. +See also C<-V:name> in L<perlrun/Command Switches>. + +=item bincompat_options() + +Returns a list of C pre-processor options used when compiling this F<perl> +binary, which affect its binary compatibility with extensions. +C<bincompat_options()> and C<non_bincompat_options()> are shown together in +the output of C<perl -V> as I<Compile-time options>. + +=item non_bincompat_options() + +Returns a list of C pre-processor options used when compiling this F<perl> +binary, which do not affect binary compatibility with extensions. + +=item compile_date() + +Returns the compile date (as a string), equivalent to what is shown by +C<perl -V> + +=item local_patches() + +Returns a list of the names of locally applied patches, equivalent to what +is shown by C<perl -V>. + +=item header_files() + +Returns a list of the header files that should be used as dependencies for +XS code, for this version of Perl on this platform. + +=back + +=head1 EXAMPLE + +Here's a more sophisticated example of using %Config: + + use Config; + use strict; + + my %sig_num; + my @sig_name; + unless($Config{sig_name} && $Config{sig_num}) { + die "No sigs?"; + } else { + my @names = split ' ', $Config{sig_name}; + @sig_num{@names} = split ' ', $Config{sig_num}; + foreach (@names) { + $sig_name[$sig_num{$_}] ||= $_; + } + } + + print "signal #17 = $sig_name[17]\n"; + if ($sig_num{ALRM}) { + print "SIGALRM is $sig_num{ALRM}\n"; + } + +=head1 WARNING + +Because this information is not stored within the perl executable +itself it is possible (but unlikely) that the information does not +relate to the actual perl binary which is being used to access it. + +The Config module is installed into the architecture and version +specific library directory ($Config{installarchlib}) and it checks the +perl version number when loaded. + +The values stored in config.sh may be either single-quoted or +double-quoted. Double-quoted strings are handy for those cases where you +need to include escape sequences in the strings. To avoid runtime variable +interpolation, any C<$> and C<@> characters are replaced by C<\$> and +C<\@>, respectively. This isn't foolproof, of course, so don't embed C<\$> +or C<\@> in double-quoted strings unless you're willing to deal with the +consequences. (The slashes will end up escaped and the C<$> or C<@> will +trigger variable interpolation) + +=head1 GLOSSARY + +Most C<Config> variables are determined by the C<Configure> script +on platforms supported by it (which is most UNIX platforms). Some +platforms have custom-made C<Config> variables, and may thus not have +some of the variables described below, or may have extraneous variables +specific to that particular port. See the port specific documentation +in such cases. + +=cut + +=head2 _ + +=over 4 + +=item C<_a> + +From F<Unix.U>: + +This variable defines the extension used for ordinary library files. +For unix, it is F<.a>. The F<.> is included. Other possible +values include F<.lib>. + +=item C<_exe> + +From F<Unix.U>: + +This variable defines the extension used for executable files. +C<DJGPP>, Cygwin and F<OS/2> use F<.exe>. Stratus C<VOS> uses F<.pm>. +On operating systems which do not require a specific extension +for executable files, this variable is empty. + +=item C<_o> + +From F<Unix.U>: + +This variable defines the extension used for object files. +For unix, it is F<.o>. The F<.> is included. Other possible +values include F<.obj>. + +=back + +=head2 a + +=over 4 + +=item C<afs> + +From F<afs.U>: + +This variable is set to C<true> if C<AFS> (Andrew File System) is used +on the system, C<false> otherwise. It is possible to override this +with a hint value or command line option, but you'd better know +what you are doing. + +=item C<afsroot> + +From F<afs.U>: + +This variable is by default set to F</afs>. In the unlikely case +this is not the correct root, it is possible to override this with +a hint value or command line option. This will be used in subsequent +tests for AFSness in the configure and test process. + +=item C<alignbytes> + +From F<alignbytes.U>: + +This variable holds the number of bytes required to align a +double-- or a long double when applicable. Usual values are +2, 4 and 8. The default is eight, for safety. + +=item C<aphostname> + +From F<d_gethname.U>: + +This variable contains the command which can be used to compute the +host name. The command is fully qualified by its absolute path, to make +it safe when used by a process with super-user privileges. + +=item C<api_revision> + +From F<patchlevel.U>: + +The three variables, api_revision, api_version, and +api_subversion, specify the version of the oldest perl binary +compatible with the present perl. In a full version string +such as F<5.6.1>, api_revision is the C<5>. +Prior to 5.5.640, the format was a floating point number, +like 5.00563. + +F<perl.c>:incpush() and F<lib/lib.pm> will automatically search in +F<$sitelib/.>. for older directories back to the limit specified +by these api_ variables. This is only useful if you have a +perl library directory tree structured like the default one. +See C<INSTALL> for how this works. The versioned site_perl +directory was introduced in 5.005, so that is the lowest +possible value. The version list appropriate for the current +system is determined in F<inc_version_list.U>. + +C<XXX> To do: Since compatibility can depend on compile time +options (such as bincompat, longlong, etc.) it should +(perhaps) be set by Configure, but currently it isn't. +Currently, we read a hard-wired value from F<patchlevel.h>. +Perhaps what we ought to do is take the hard-wired value from +F<patchlevel.h> but then modify it if the current Configure +options warrant. F<patchlevel.h> then would use an #ifdef guard. + +=item C<api_subversion> + +From F<patchlevel.U>: + +The three variables, api_revision, api_version, and +api_subversion, specify the version of the oldest perl binary +compatible with the present perl. In a full version string +such as F<5.6.1>, api_subversion is the C<1>. See api_revision for +full details. + +=item C<api_version> + +From F<patchlevel.U>: + +The three variables, api_revision, api_version, and +api_subversion, specify the version of the oldest perl binary +compatible with the present perl. In a full version string +such as F<5.6.1>, api_version is the C<6>. See api_revision for +full details. As a special case, 5.5.0 is rendered in the +old-style as 5.005. (In the 5.005_0x maintenance series, +this was the only versioned directory in $sitelib.) + +=item C<api_versionstring> + +From F<patchlevel.U>: + +This variable combines api_revision, api_version, and +api_subversion in a format such as 5.6.1 (or 5_6_1) suitable +for use as a directory name. This is filesystem dependent. + +=item C<ar> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the ar program. After Configure runs, +the value is reset to a plain C<ar> and is not useful. + +=item C<archlib> + +From F<archlib.U>: + +This variable holds the name of the directory in which the user wants +to put architecture-dependent public library files for $package. +It is most often a local directory such as F</usr/local/lib>. +Programs using this variable must be prepared to deal +with filename expansion. + +=item C<archlibexp> + +From F<archlib.U>: + +This variable is the same as the archlib variable, but is +filename expanded at configuration time, for convenient use. + +=item C<archname> + +From F<archname.U>: + +This variable is a short name to characterize the current +architecture. It is used mainly to construct the default archlib. + +=item C<archname64> + +From F<use64bits.U>: + +This variable is used for the 64-bitness part of $archname. + +=item C<archobjs> + +From F<Unix.U>: + +This variable defines any additional objects that must be linked +in with the program on this architecture. On unix, it is usually +empty. It is typically used to include emulations of unix calls +or other facilities. For perl on F<OS/2>, for example, this would +include F<os2/os2.obj>. + +=item C<asctime_r_proto> + +From F<d_asctime_r.U>: + +This variable encodes the prototype of asctime_r. +It is zero if d_asctime_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_asctime_r +is defined. + +=item C<awk> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the awk program. After Configure runs, +the value is reset to a plain C<awk> and is not useful. + +=back + +=head2 b + +=over 4 + +=item C<baserev> + +From F<baserev.U>: + +The base revision level of this package, from the F<.package> file. + +=item C<bash> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<bin> + +From F<bin.U>: + +This variable holds the name of the directory in which the user wants +to put publicly executable images for the package in question. It +is most often a local directory such as F</usr/local/bin>. Programs using +this variable must be prepared to deal with F<~name> substitution. + +=item C<bin_ELF> + +From F<dlsrc.U>: + +This variable saves the result from configure if generated binaries +are in C<ELF> format. Only set to defined when the test has actually +been performed, and the result was positive. + +=item C<binexp> + +From F<bin.U>: + +This is the same as the bin variable, but is filename expanded at +configuration time, for use in your makefiles. + +=item C<bison> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the bison program. After Configure runs, +the value is reset to a plain C<bison> and is not useful. + +=item C<byacc> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the byacc program. After Configure runs, +the value is reset to a plain C<byacc> and is not useful. + +=item C<byteorder> + +From F<byteorder.U>: + +This variable holds the byte order in a C<UV>. In the following, +larger digits indicate more significance. The variable byteorder +is either 4321 on a big-endian machine, or 1234 on a little-endian, +or 87654321 on a Cray ... or 3412 with weird order ! + +=back + +=head2 c + +=over 4 + +=item C<c> + +From F<n.U>: + +This variable contains the \c string if that is what causes the echo +command to suppress newline. Otherwise it is null. Correct usage is +$echo $n "prompt for a question: $c". + +=item C<castflags> + +From F<d_castneg.U>: + +This variable contains a flag that precise difficulties the +compiler has casting odd floating values to unsigned long: +0 = ok +1 = couldn't cast < 0 +2 = couldn't cast >= 0x80000000 +4 = couldn't cast in argument expression list + +=item C<cat> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the cat program. After Configure runs, +the value is reset to a plain C<cat> and is not useful. + +=item C<cc> + +From F<cc.U>: + +This variable holds the name of a command to execute a C compiler which +can resolve multiple global references that happen to have the same +name. Usual values are C<cc> and C<gcc>. +Fervent C<ANSI> compilers may be called C<c89>. C<AIX> has xlc. + +=item C<cccdlflags> + +From F<dlsrc.U>: + +This variable contains any special flags that might need to be +passed with C<cc -c> to compile modules to be used to create a shared +library that will be used for dynamic loading. For hpux, this +should be +z. It is up to the makefile to use it. + +=item C<ccdlflags> + +From F<dlsrc.U>: + +This variable contains any special flags that might need to be +passed to cc to link with a shared library for dynamic loading. +It is up to the makefile to use it. For sunos 4.1, it should +be empty. + +=item C<ccflags> + +From F<ccflags.U>: + +This variable contains any additional C compiler flags desired by +the user. It is up to the Makefile to use this. + +=item C<ccflags_uselargefiles> + +From F<uselfs.U>: + +This variable contains the compiler flags needed by large file builds +and added to ccflags by hints files. + +=item C<ccname> + +From F<Checkcc.U>: + +This can set either by hints files or by Configure. If using +gcc, this is gcc, and if not, usually equal to cc, unimpressive, no? +Some platforms, however, make good use of this by storing the +flavor of the C compiler being used here. For example if using +the Sun WorkShop suite, ccname will be C<workshop>. + +=item C<ccsymbols> + +From F<Cppsym.U>: + +The variable contains the symbols defined by the C compiler alone. +The symbols defined by cpp or by cc when it calls cpp are not in +this list, see cppsymbols and cppccsymbols. +The list is a space-separated list of symbol=value tokens. + +=item C<ccversion> + +From F<Checkcc.U>: + +This can set either by hints files or by Configure. If using +a (non-gcc) vendor cc, this variable may contain a version for +the compiler. + +=item C<cf_by> + +From F<cf_who.U>: + +Login name of the person who ran the Configure script and answered the +questions. This is used to tag both F<config.sh> and F<config_h.SH>. + +=item C<cf_email> + +From F<cf_email.U>: + +Electronic mail address of the person who ran Configure. This can be +used by units that require the user's e-mail, like F<MailList.U>. + +=item C<cf_time> + +From F<cf_who.U>: + +Holds the output of the C<date> command when the configuration file was +produced. This is used to tag both F<config.sh> and F<config_h.SH>. + +=item C<charbits> + +From F<charsize.U>: + +This variable contains the value of the C<CHARBITS> symbol, which +indicates to the C program how many bits there are in a character. + +=item C<charsize> + +From F<charsize.U>: + +This variable contains the value of the C<CHARSIZE> symbol, which +indicates to the C program how many bytes there are in a character. + +=item C<chgrp> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<chmod> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the chmod program. After Configure runs, +the value is reset to a plain C<chmod> and is not useful. + +=item C<chown> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<clocktype> + +From F<d_times.U>: + +This variable holds the type returned by times(). It can be long, +or clock_t on C<BSD> sites (in which case <sys/types.h> should be +included). + +=item C<comm> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the comm program. After Configure runs, +the value is reset to a plain C<comm> and is not useful. + +=item C<compiler_warning> + +From F<compiler_warning.U>: + +This variable holds the command to check if the file specified as a +parameter contains a compiler warning + +=item C<compress> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<config_arg0> + +From F<Options.U>: + +This variable contains the string used to invoke the Configure +command, as reported by the shell in the $0 variable. + +=item C<config_argc> + +From F<Options.U>: + +This variable contains the number of command-line arguments +passed to Configure, as reported by the shell in the $# variable. +The individual arguments are stored as variables config_arg1, +config_arg2, etc. + +=item C<config_args> + +From F<Options.U>: + +This variable contains a single string giving the command-line +arguments passed to Configure. Spaces within arguments, +quotes, and escaped characters are not correctly preserved. +To reconstruct the command line, you must assemble the individual +command line pieces, given in config_arg[0-9]*. + +=item C<contains> + +From F<contains.U>: + +This variable holds the command to do a grep with a proper return +status. On most sane systems it is simply C<grep>. On insane systems +it is a grep followed by a cat followed by a test. This variable +is primarily for the use of other Configure units. + +=item C<cp> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the cp program. After Configure runs, +the value is reset to a plain C<cp> and is not useful. + +=item C<cpio> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<cpp> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the cpp program. After Configure runs, +the value is reset to a plain C<cpp> and is not useful. + +=item C<cpp_stuff> + +From F<cpp_stuff.U>: + +This variable contains an identification of the concatenation mechanism +used by the C preprocessor. + +=item C<cppccsymbols> + +From F<Cppsym.U>: + +The variable contains the symbols defined by the C compiler +when it calls cpp. The symbols defined by the cc alone or cpp +alone are not in this list, see ccsymbols and cppsymbols. +The list is a space-separated list of symbol=value tokens. + +=item C<cppflags> + +From F<ccflags.U>: + +This variable holds the flags that will be passed to the C pre- +processor. It is up to the Makefile to use it. + +=item C<cpplast> + +From F<cppstdin.U>: + +This variable has the same functionality as cppminus, only it applies +to cpprun and not cppstdin. + +=item C<cppminus> + +From F<cppstdin.U>: + +This variable contains the second part of the string which will invoke +the C preprocessor on the standard input and produce to standard +output. This variable will have the value C<-> if cppstdin needs +a minus to specify standard input, otherwise the value is "". + +=item C<cpprun> + +From F<cppstdin.U>: + +This variable contains the command which will invoke a C preprocessor +on standard input and put the output to stdout. It is guaranteed not +to be a wrapper and may be a null string if no preprocessor can be +made directly available. This preprocessor might be different from the +one used by the C compiler. Don't forget to append cpplast after the +preprocessor options. + +=item C<cppstdin> + +From F<cppstdin.U>: + +This variable contains the command which will invoke the C +preprocessor on standard input and put the output to stdout. +It is primarily used by other Configure units that ask about +preprocessor symbols. + +=item C<cppsymbols> + +From F<Cppsym.U>: + +The variable contains the symbols defined by the C preprocessor +alone. The symbols defined by cc or by cc when it calls cpp are +not in this list, see ccsymbols and cppccsymbols. +The list is a space-separated list of symbol=value tokens. + +=item C<crypt_r_proto> + +From F<d_crypt_r.U>: + +This variable encodes the prototype of crypt_r. +It is zero if d_crypt_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_crypt_r +is defined. + +=item C<cryptlib> + +From F<d_crypt.U>: + +This variable holds -lcrypt or the path to a F<libcrypt.a> archive if +the crypt() function is not defined in the standard C library. It is +up to the Makefile to use this. + +=item C<csh> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the csh program. After Configure runs, +the value is reset to a plain C<csh> and is not useful. + +=item C<ctermid_r_proto> + +From F<d_ctermid_r.U>: + +This variable encodes the prototype of ctermid_r. +It is zero if d_ctermid_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_ctermid_r +is defined. + +=item C<ctime_r_proto> + +From F<d_ctime_r.U>: + +This variable encodes the prototype of ctime_r. +It is zero if d_ctime_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_ctime_r +is defined. + +=back + +=head2 d + +=over 4 + +=item C<d__fwalk> + +From F<d__fwalk.U>: + +This variable conditionally defines C<HAS__FWALK> if _fwalk() is +available to apply a function to all the file handles. + +=item C<d_accept4> + +From F<d_accept4.U>: + +This variable conditionally defines HAS_ACCEPT4 if accept4() is +available to accept socket connections. + +=item C<d_access> + +From F<d_access.U>: + +This variable conditionally defines C<HAS_ACCESS> if the access() system +call is available to check for access permissions using real IDs. + +=item C<d_accessx> + +From F<d_accessx.U>: + +This variable conditionally defines the C<HAS_ACCESSX> symbol, which +indicates to the C program that the accessx() routine is available. + +=item C<d_acosh> + +From F<d_acosh.U>: + +This variable conditionally defines the C<HAS_ACOSH> symbol, which +indicates to the C program that the acosh() routine is available. + +=item C<d_aintl> + +From F<d_aintl.U>: + +This variable conditionally defines the C<HAS_AINTL> symbol, which +indicates to the C program that the aintl() routine is available. +If copysignl is also present we can emulate modfl. + +=item C<d_alarm> + +From F<d_alarm.U>: + +This variable conditionally defines the C<HAS_ALARM> symbol, which +indicates to the C program that the alarm() routine is available. + +=item C<d_archlib> + +From F<archlib.U>: + +This variable conditionally defines C<ARCHLIB> to hold the pathname +of architecture-dependent library files for $package. If +$archlib is the same as $privlib, then this is set to undef. + +=item C<d_asctime64> + +From F<d_timefuncs64.U>: + +This variable conditionally defines the HAS_ASCTIME64 symbol, which +indicates to the C program that the asctime64 () routine is available. + +=item C<d_asctime_r> + +From F<d_asctime_r.U>: + +This variable conditionally defines the C<HAS_ASCTIME_R> symbol, +which indicates to the C program that the asctime_r() +routine is available. + +=item C<d_asinh> + +From F<d_asinh.U>: + +This variable conditionally defines the C<HAS_ASINH> symbol, which +indicates to the C program that the asinh() routine is available. + +=item C<d_atanh> + +From F<d_atanh.U>: + +This variable conditionally defines the C<HAS_ATANH> symbol, which +indicates to the C program that the atanh() routine is available. + +=item C<d_atolf> + +From F<atolf.U>: + +This variable conditionally defines the C<HAS_ATOLF> symbol, which +indicates to the C program that the atolf() routine is available. + +=item C<d_atoll> + +From F<atoll.U>: + +This variable conditionally defines the C<HAS_ATOLL> symbol, which +indicates to the C program that the atoll() routine is available. + +=item C<d_attribute_always_inline> + +From F<d_attribut.U>: + +This variable conditionally defines C<HASATTRIBUTE_ALWAYS_INLINE>, +which indicates that the C compiler can know that certain +functions should always be inlined. + +=item C<d_attribute_deprecated> + +From F<d_attribut.U>: + +This variable conditionally defines C<HASATTRIBUTE_DEPRECATED>, which +indicates that C<GCC> can handle the attribute for marking deprecated +APIs + +=item C<d_attribute_format> + +From F<d_attribut.U>: + +This variable conditionally defines C<HASATTRIBUTE_FORMAT>, which +indicates the C compiler can check for printf-like formats. + +=item C<d_attribute_malloc> + +From F<d_attribut.U>: + +This variable conditionally defines C<HASATTRIBUTE_MALLOC>, which +indicates the C compiler can understand functions as having +malloc-like semantics. + +=item C<d_attribute_nonnull> + +From F<d_attribut.U>: + +This variable conditionally defines C<HASATTRIBUTE_NONNULL>, which +indicates that the C compiler can know that certain arguments +must not be C<NULL>, and will check accordingly at compile time. + +=item C<d_attribute_noreturn> + +From F<d_attribut.U>: + +This variable conditionally defines C<HASATTRIBUTE_NORETURN>, which +indicates that the C compiler can know that certain functions +are guaranteed never to return. + +=item C<d_attribute_pure> + +From F<d_attribut.U>: + +This variable conditionally defines C<HASATTRIBUTE_PURE>, which +indicates that the C compiler can know that certain functions +are C<pure> functions, meaning that they have no side effects, and +only rely on function input F<and/or> global data for their results. + +=item C<d_attribute_unused> + +From F<d_attribut.U>: + +This variable conditionally defines C<HASATTRIBUTE_UNUSED>, which +indicates that the C compiler can know that certain variables +and arguments may not always be used, and to not throw warnings +if they don't get used. + +=item C<d_attribute_warn_unused_result> + +From F<d_attribut.U>: + +This variable conditionally defines +C<HASATTRIBUTE_WARN_UNUSED_RESULT>, which indicates that the C +compiler can know that certain functions have a return values +that must not be ignored, such as malloc() or open(). + +=item C<d_backtrace> + +From F<d_backtrace.U>: + +This variable conditionally defines the C<HAS_BACKTRACE> symbol, which +indicates to the C program that the backtrace() routine is available +to get a stack trace. + +=item C<d_bsd> + +From F<Guess.U>: + +This symbol conditionally defines the symbol C<BSD> when running on a +C<BSD> system. + +=item C<d_bsdgetpgrp> + +From F<d_getpgrp.U>: + +This variable conditionally defines C<USE_BSD_GETPGRP> if +getpgrp needs one arguments whereas C<USG> one needs none. + +=item C<d_bsdsetpgrp> + +From F<d_setpgrp.U>: + +This variable conditionally defines C<USE_BSD_SETPGRP> if +setpgrp needs two arguments whereas C<USG> one needs none. +See also d_setpgid for a C<POSIX> interface. + +=item C<d_builtin_add_overflow> + +From F<d_builtin_overflow.U>: + +This variable conditionally defines C<HAS_BUILTIN_ADD_OVERFLOW>, which +indicates that the compiler supports __builtin_add_overflow(x,y,&z) +for safely adding x and y into z while checking for overflow. + +=item C<d_builtin_choose_expr> + +From F<d_builtin.U>: + +This conditionally defines C<HAS_BUILTIN_CHOOSE_EXPR>, which +indicates that the compiler supports __builtin_choose_expr(x,y,z). +This built-in function is analogous to the C<x?y:z> operator in C, +except that the expression returned has its type unaltered by +promotion rules. Also, the built-in function does not evaluate +the expression that was not chosen. + +=item C<d_builtin_expect> + +From F<d_builtin.U>: + +This conditionally defines C<HAS_BUILTIN_EXPECT>, which indicates +that the compiler supports __builtin_expect(exp,c). You may use +__builtin_expect to provide the compiler with branch prediction +information. + +=item C<d_builtin_mul_overflow> + +From F<d_builtin_overflow.U>: + +This variable conditionally defines C<HAS_BUILTIN_MUL_OVERFLOW>, which +indicates that the compiler supports __builtin_mul_overflow(x,y,&z) +for safely multiplying x and y into z while checking for overflow. + +=item C<d_builtin_sub_overflow> + +From F<d_builtin_overflow.U>: + +This variable conditionally defines C<HAS_BUILTIN_SUB_OVERFLOW>, which +indicates that the compiler supports __builtin_sub_overflow(x,y,&z) +for safely subtracting y from x into z while checking for overflow. + +=item C<d_c99_variadic_macros> + +From F<d_c99_variadic.U>: + +This variable conditionally defines the HAS_C99_VARIADIC_MACROS +symbol, which indicates to the C program that C99 variadic macros +are available. + +=item C<d_casti32> + +From F<d_casti32.U>: + +This variable conditionally defines CASTI32, which indicates +whether the C compiler can cast large floats to 32-bit ints. + +=item C<d_castneg> + +From F<d_castneg.U>: + +This variable conditionally defines C<CASTNEG>, which indicates +whether the C compiler can cast negative float to unsigned. + +=item C<d_cbrt> + +From F<d_cbrt.U>: + +This variable conditionally defines the C<HAS_CBRT> symbol, which +indicates to the C program that the cbrt() (cube root) function +is available. + +=item C<d_chown> + +From F<d_chown.U>: + +This variable conditionally defines the C<HAS_CHOWN> symbol, which +indicates to the C program that the chown() routine is available. + +=item C<d_chroot> + +From F<d_chroot.U>: + +This variable conditionally defines the C<HAS_CHROOT> symbol, which +indicates to the C program that the chroot() routine is available. + +=item C<d_chsize> + +From F<d_chsize.U>: + +This variable conditionally defines the C<CHSIZE> symbol, which +indicates to the C program that the chsize() routine is available +to truncate files. You might need a -lx to get this routine. + +=item C<d_class> + +From F<d_class.U>: + +This variable conditionally defines the C<HAS_CLASS> symbol, which +indicates to the C program that the class() routine is available. + +=item C<d_clearenv> + +From F<d_clearenv.U>: + +This variable conditionally defines the C<HAS_CLEARENV> symbol, which +indicates to the C program that the clearenv () routine is available. + +=item C<d_closedir> + +From F<d_closedir.U>: + +This variable conditionally defines C<HAS_CLOSEDIR> if closedir() is +available. + +=item C<d_cmsghdr_s> + +From F<d_cmsghdr_s.U>: + +This variable conditionally defines the C<HAS_STRUCT_CMSGHDR> symbol, +which indicates that the struct cmsghdr is supported. + +=item C<d_copysign> + +From F<d_copysign.U>: + +This variable conditionally defines the C<HAS_COPYSIGN> symbol, which +indicates to the C program that the copysign() routine is available. + +=item C<d_copysignl> + +From F<d_copysignl.U>: + +This variable conditionally defines the C<HAS_COPYSIGNL> symbol, which +indicates to the C program that the copysignl() routine is available. +If aintl is also present we can emulate modfl. + +=item C<d_cplusplus> + +From F<d_cplusplus.U>: + +This variable conditionally defines the C<USE_CPLUSPLUS> symbol, which +indicates that a C++ compiler was used to compiled Perl and will be +used to compile extensions. + +=item C<d_crypt> + +From F<d_crypt.U>: + +This variable conditionally defines the C<CRYPT> symbol, which +indicates to the C program that the crypt() routine is available +to encrypt passwords and the like. + +=item C<d_crypt_r> + +From F<d_crypt_r.U>: + +This variable conditionally defines the C<HAS_CRYPT_R> symbol, +which indicates to the C program that the crypt_r() +routine is available. + +=item C<d_csh> + +From F<d_csh.U>: + +This variable conditionally defines the C<CSH> symbol, which +indicates to the C program that the C-shell exists. + +=item C<d_ctermid> + +From F<d_ctermid.U>: + +This variable conditionally defines C<CTERMID> if ctermid() is +available to generate filename for terminal. + +=item C<d_ctermid_r> + +From F<d_ctermid_r.U>: + +This variable conditionally defines the C<HAS_CTERMID_R> symbol, +which indicates to the C program that the ctermid_r() +routine is available. + +=item C<d_ctime64> + +From F<d_timefuncs64.U>: + +This variable conditionally defines the HAS_CTIME64 symbol, which +indicates to the C program that the ctime64 () routine is available. + +=item C<d_ctime_r> + +From F<d_ctime_r.U>: + +This variable conditionally defines the C<HAS_CTIME_R> symbol, +which indicates to the C program that the ctime_r() +routine is available. + +=item C<d_cuserid> + +From F<d_cuserid.U>: + +This variable conditionally defines the C<HAS_CUSERID> symbol, which +indicates to the C program that the cuserid() routine is available +to get character login names. + +=item C<d_dbminitproto> + +From F<d_dbminitproto.U>: + +This variable conditionally defines the C<HAS_DBMINIT_PROTO> symbol, +which indicates to the C program that the system provides +a prototype for the dbminit() function. Otherwise, it is +up to the program to supply one. + +=item C<d_difftime> + +From F<d_difftime.U>: + +This variable conditionally defines the C<HAS_DIFFTIME> symbol, which +indicates to the C program that the difftime() routine is available. + +=item C<d_difftime64> + +From F<d_timefuncs64.U>: + +This variable conditionally defines the HAS_DIFFTIME64 symbol, which +indicates to the C program that the difftime64 () routine is available. + +=item C<d_dir_dd_fd> + +From F<d_dir_dd_fd.U>: + +This variable conditionally defines the C<HAS_DIR_DD_FD> symbol, which +indicates that the C<DIR> directory stream type contains a member +variable called dd_fd. + +=item C<d_dirfd> + +From F<d_dirfd.U>: + +This variable conditionally defines the C<HAS_DIRFD> constant, +which indicates to the C program that dirfd() is available +to return the file descriptor of a directory stream. + +=item C<d_dirnamlen> + +From F<i_dirent.U>: + +This variable conditionally defines C<DIRNAMLEN>, which indicates +to the C program that the length of directory entry names is +provided by a d_namelen field. + +=item C<d_dladdr> + +From F<d_dladdr.U>: + +This variable conditionally defines the C<HAS_DLADDR> symbol, which +indicates to the C program that the dladdr() routine is available +to get a stack trace. + +=item C<d_dlerror> + +From F<d_dlerror.U>: + +This variable conditionally defines the C<HAS_DLERROR> symbol, which +indicates to the C program that the dlerror() routine is available. + +=item C<d_dlopen> + +From F<d_dlopen.U>: + +This variable conditionally defines the C<HAS_DLOPEN> symbol, which +indicates to the C program that the dlopen() routine is available. + +=item C<d_dlsymun> + +From F<d_dlsymun.U>: + +This variable conditionally defines C<DLSYM_NEEDS_UNDERSCORE>, which +indicates that we need to prepend an underscore to the symbol +name before calling dlsym(). + +=item C<d_dosuid> + +From F<d_dosuid.U>: + +This variable conditionally defines the symbol C<DOSUID>, which +tells the C program that it should insert setuid emulation code +on hosts which have setuid #! scripts disabled. + +=item C<d_double_has_inf> + +From F<longdblfio.U>: + +This variable conditionally defines the symbol C<DOUBLE_HAS_INF> +which indicates that the double type has an infinity. + +=item C<d_double_has_nan> + +From F<longdblfio.U>: + +This variable conditionally defines the symbol C<DOUBLE_HAS_NAN> +which indicates that the double type has a not-a-number. + +=item C<d_double_has_negative_zero> + +From F<longdblfio.U>: + +This variable conditionally defines the symbol C<DOUBLE_HAS_NEGATIVE_ZERO> +which indicates that the double type has a negative zero. + +=item C<d_double_has_subnormals> + +From F<longdblfio.U>: + +This variable conditionally defines the symbol C<DOUBLE_HAS_SUBNORMALS> +which indicates that the double type has subnormals (denormals). + +=item C<d_double_style_cray> + +From F<longdblfio.U>: + +This variable conditionally defines the symbol C<DOUBLE_STYLE_CRAY> +which indicates that the double is the 64-bit C<CRAY> mainframe format. + +=item C<d_double_style_ibm> + +From F<longdblfio.U>: + +This variable conditionally defines the symbol C<DOUBLE_STYLE_IBM>, +which indicates that the double is the 64-bit C<IBM> mainframe format. + +=item C<d_double_style_ieee> + +From F<longdblfio.U>: + +This variable conditionally defines the symbol C<DOUBLE_STYLE_IEEE>, +which indicates that the double is the 64-bit C<IEEE> 754. + +=item C<d_double_style_vax> + +From F<longdblfio.U>: + +This variable conditionally defines the symbol C<DOUBLE_STYLE_VAX>, +which indicates that the double is the 64-bit C<VAX> format D or G. + +=item C<d_drand48_r> + +From F<d_drand48_r.U>: + +This variable conditionally defines the HAS_DRAND48_R symbol, +which indicates to the C program that the drand48_r() +routine is available. + +=item C<d_drand48proto> + +From F<d_drand48proto.U>: + +This variable conditionally defines the HAS_DRAND48_PROTO symbol, +which indicates to the C program that the system provides +a prototype for the drand48() function. Otherwise, it is +up to the program to supply one. + +=item C<d_dup2> + +From F<d_dup2.U>: + +This variable conditionally defines HAS_DUP2 if dup2() is +available to duplicate file descriptors. + +=item C<d_dup3> + +From F<d_dup3.U>: + +This variable conditionally defines HAS_DUP3 if dup3() is +available to duplicate file descriptors. + +=item C<d_duplocale> + +From F<d_newlocale.U>: + +This variable conditionally defines the C<HAS_DUPLOCALE> symbol, which +indicates to the C program that the duplocale() routine is available +to duplicate a locale object. + +=item C<d_eaccess> + +From F<d_eaccess.U>: + +This variable conditionally defines the C<HAS_EACCESS> symbol, which +indicates to the C program that the eaccess() routine is available. + +=item C<d_endgrent> + +From F<d_endgrent.U>: + +This variable conditionally defines the C<HAS_ENDGRENT> symbol, which +indicates to the C program that the endgrent() routine is available +for sequential access of the group database. + +=item C<d_endgrent_r> + +From F<d_endgrent_r.U>: + +This variable conditionally defines the C<HAS_ENDGRENT_R> symbol, +which indicates to the C program that the endgrent_r() +routine is available. + +=item C<d_endhent> + +From F<d_endhent.U>: + +This variable conditionally defines C<HAS_ENDHOSTENT> if endhostent() is +available to close whatever was being used for host queries. + +=item C<d_endhostent_r> + +From F<d_endhostent_r.U>: + +This variable conditionally defines the C<HAS_ENDHOSTENT_R> symbol, +which indicates to the C program that the endhostent_r() +routine is available. + +=item C<d_endnent> + +From F<d_endnent.U>: + +This variable conditionally defines C<HAS_ENDNETENT> if endnetent() is +available to close whatever was being used for network queries. + +=item C<d_endnetent_r> + +From F<d_endnetent_r.U>: + +This variable conditionally defines the C<HAS_ENDNETENT_R> symbol, +which indicates to the C program that the endnetent_r() +routine is available. + +=item C<d_endpent> + +From F<d_endpent.U>: + +This variable conditionally defines C<HAS_ENDPROTOENT> if endprotoent() is +available to close whatever was being used for protocol queries. + +=item C<d_endprotoent_r> + +From F<d_endprotoent_r.U>: + +This variable conditionally defines the C<HAS_ENDPROTOENT_R> symbol, +which indicates to the C program that the endprotoent_r() +routine is available. + +=item C<d_endpwent> + +From F<d_endpwent.U>: + +This variable conditionally defines the C<HAS_ENDPWENT> symbol, which +indicates to the C program that the endpwent() routine is available +for sequential access of the passwd database. + +=item C<d_endpwent_r> + +From F<d_endpwent_r.U>: + +This variable conditionally defines the C<HAS_ENDPWENT_R> symbol, +which indicates to the C program that the endpwent_r() +routine is available. + +=item C<d_endsent> + +From F<d_endsent.U>: + +This variable conditionally defines C<HAS_ENDSERVENT> if endservent() is +available to close whatever was being used for service queries. + +=item C<d_endservent_r> + +From F<d_endservent_r.U>: + +This variable conditionally defines the C<HAS_ENDSERVENT_R> symbol, +which indicates to the C program that the endservent_r() +routine is available. + +=item C<d_eofnblk> + +From F<nblock_io.U>: + +This variable conditionally defines C<EOF_NONBLOCK> if C<EOF> can be seen +when reading from a non-blocking I/O source. + +=item C<d_erf> + +From F<d_erf.U>: + +This variable conditionally defines the C<HAS_ERF> symbol, which +indicates to the C program that the erf() routine is available. + +=item C<d_erfc> + +From F<d_erfc.U>: + +This variable conditionally defines the C<HAS_ERFC> symbol, which +indicates to the C program that the erfc() routine is available. + +=item C<d_eunice> + +From F<Guess.U>: + +This variable conditionally defines the symbols C<EUNICE> and C<VAX>, which +alerts the C program that it must deal with idiosyncrasies of C<VMS>. + +=item C<d_exp2> + +From F<d_exp2.U>: + +This variable conditionally defines the HAS_EXP2 symbol, which +indicates to the C program that the exp2() routine is available. + +=item C<d_expm1> + +From F<d_expm1.U>: + +This variable conditionally defines the HAS_EXPM1 symbol, which +indicates to the C program that the expm1() routine is available. + +=item C<d_faststdio> + +From F<d_faststdio.U>: + +This variable conditionally defines the C<HAS_FAST_STDIO> symbol, +which indicates to the C program that the "fast stdio" is available +to manipulate the stdio buffers directly. + +=item C<d_fchdir> + +From F<d_fchdir.U>: + +This variable conditionally defines the C<HAS_FCHDIR> symbol, which +indicates to the C program that the fchdir() routine is available. + +=item C<d_fchmod> + +From F<d_fchmod.U>: + +This variable conditionally defines the C<HAS_FCHMOD> symbol, which +indicates to the C program that the fchmod() routine is available +to change mode of opened files. + +=item C<d_fchmodat> + +From F<d_fsat.U>: + +This variable conditionally defines the C<HAS_FCHMODAT> symbol, which +indicates the C<POSIX> fchmodat() function is available. + +=item C<d_fchown> + +From F<d_fchown.U>: + +This variable conditionally defines the C<HAS_FCHOWN> symbol, which +indicates to the C program that the fchown() routine is available +to change ownership of opened files. + +=item C<d_fcntl> + +From F<d_fcntl.U>: + +This variable conditionally defines the C<HAS_FCNTL> symbol, and indicates +whether the fcntl() function exists + +=item C<d_fcntl_can_lock> + +From F<d_fcntl_can_lock.U>: + +This variable conditionally defines the C<FCNTL_CAN_LOCK> symbol +and indicates whether file locking with fcntl() works. + +=item C<d_fd_macros> + +From F<d_fd_set.U>: + +This variable contains the eventual value of the C<HAS_FD_MACROS> symbol, +which indicates if your C compiler knows about the macros which +manipulate an fd_set. + +=item C<d_fd_set> + +From F<d_fd_set.U>: + +This variable contains the eventual value of the C<HAS_FD_SET> symbol, +which indicates if your C compiler knows about the fd_set typedef. + +=item C<d_fdclose> + +From F<d_fdclose.U>: + +This variable conditionally defines the C<HAS_FDCLOSE> symbol, which +indicates to the C program that the fdclose() routine is available. + +=item C<d_fdim> + +From F<d_fdim.U>: + +This variable conditionally defines the C<HAS_FDIM> symbol, which +indicates to the C program that the fdim() routine is available. + +=item C<d_fds_bits> + +From F<d_fd_set.U>: + +This variable contains the eventual value of the C<HAS_FDS_BITS> symbol, +which indicates if your fd_set typedef contains the fds_bits member. +If you have an fd_set typedef, but the dweebs who installed it did +a half-fast job and neglected to provide the macros to manipulate +an fd_set, C<HAS_FDS_BITS> will let us know how to fix the gaffe. + +=item C<d_fegetround> + +From F<d_fegetround.U>: + +This variable conditionally defines C<HAS_FEGETROUND> if fegetround() is +available to get the floating point rounding mode. + +=item C<d_fgetpos> + +From F<d_fgetpos.U>: + +This variable conditionally defines C<HAS_FGETPOS> if fgetpos() is +available to get the file position indicator. + +=item C<d_finite> + +From F<d_finite.U>: + +This variable conditionally defines the C<HAS_FINITE> symbol, which +indicates to the C program that the finite() routine is available. + +=item C<d_finitel> + +From F<d_finitel.U>: + +This variable conditionally defines the C<HAS_FINITEL> symbol, which +indicates to the C program that the finitel() routine is available. + +=item C<d_flexfnam> + +From F<d_flexfnam.U>: + +This variable conditionally defines the C<FLEXFILENAMES> symbol, which +indicates that the system supports filenames longer than 14 characters. + +=item C<d_flock> + +From F<d_flock.U>: + +This variable conditionally defines C<HAS_FLOCK> if flock() is +available to do file locking. + +=item C<d_flockproto> + +From F<d_flockproto.U>: + +This variable conditionally defines the C<HAS_FLOCK_PROTO> symbol, +which indicates to the C program that the system provides +a prototype for the flock() function. Otherwise, it is +up to the program to supply one. + +=item C<d_fma> + +From F<d_fma.U>: + +This variable conditionally defines the C<HAS_FMA> symbol, which +indicates to the C program that the fma() routine is available. + +=item C<d_fmax> + +From F<d_fmax.U>: + +This variable conditionally defines the C<HAS_FMAX> symbol, which +indicates to the C program that the fmax() routine is available. + +=item C<d_fmin> + +From F<d_fmin.U>: + +This variable conditionally defines the C<HAS_FMIN> symbol, which +indicates to the C program that the fmin() routine is available. + +=item C<d_fork> + +From F<d_fork.U>: + +This variable conditionally defines the C<HAS_FORK> symbol, which +indicates to the C program that the fork() routine is available. + +=item C<d_fp_class> + +From F<d_fp_class.U>: + +This variable conditionally defines the C<HAS_FP_CLASS> symbol, which +indicates to the C program that the fp_class() routine is available. + +=item C<d_fp_classify> + +From F<d_fpclassify.U>: + +This variable conditionally defines the C<HAS_FP_CLASSIFY> symbol, which +indicates to the C program that the fp_classify() routine is available. + +=item C<d_fp_classl> + +From F<d_fp_classl.U>: + +This variable conditionally defines the C<HAS_FP_CLASSL> symbol, which +indicates to the C program that the fp_classl() routine is available. + +=item C<d_fpathconf> + +From F<d_pathconf.U>: + +This variable conditionally defines the C<HAS_FPATHCONF> symbol, which +indicates to the C program that the pathconf() routine is available +to determine file-system related limits and options associated +with a given open file descriptor. + +=item C<d_fpclass> + +From F<d_fpclass.U>: + +This variable conditionally defines the C<HAS_FPCLASS> symbol, which +indicates to the C program that the fpclass() routine is available. + +=item C<d_fpclassify> + +From F<d_fpclassify.U>: + +This variable conditionally defines the C<HAS_FPCLASSIFY> symbol, which +indicates to the C program that the fpclassify() routine is available. + +=item C<d_fpclassl> + +From F<d_fpclassl.U>: + +This variable conditionally defines the C<HAS_FPCLASSL> symbol, which +indicates to the C program that the fpclassl() routine is available. + +=item C<d_fpgetround> + +From F<d_fpgetround.U>: + +This variable conditionally defines C<HAS_FPGETROUND> if fpgetround() +is available to get the floating point rounding mode. + +=item C<d_fpos64_t> + +From F<d_fpos64_t.U>: + +This symbol will be defined if the C compiler supports fpos64_t. + +=item C<d_freelocale> + +From F<d_newlocale.U>: + +This variable conditionally defines the C<HAS_FREELOCALE> symbol, which +indicates to the C program that the freelocale() routine is available +to deallocates the resources associated with a locale object. + +=item C<d_frexpl> + +From F<d_frexpl.U>: + +This variable conditionally defines the C<HAS_FREXPL> symbol, which +indicates to the C program that the frexpl() routine is available. + +=item C<d_fs_data_s> + +From F<d_fs_data_s.U>: + +This variable conditionally defines the C<HAS_STRUCT_FS_DATA> symbol, +which indicates that the struct fs_data is supported. + +=item C<d_fseeko> + +From F<d_fseeko.U>: + +This variable conditionally defines the C<HAS_FSEEKO> symbol, which +indicates to the C program that the fseeko() routine is available. + +=item C<d_fsetpos> + +From F<d_fsetpos.U>: + +This variable conditionally defines C<HAS_FSETPOS> if fsetpos() is +available to set the file position indicator. + +=item C<d_fstatfs> + +From F<d_fstatfs.U>: + +This variable conditionally defines the C<HAS_FSTATFS> symbol, which +indicates to the C program that the fstatfs() routine is available. + +=item C<d_fstatvfs> + +From F<d_statvfs.U>: + +This variable conditionally defines the C<HAS_FSTATVFS> symbol, which +indicates to the C program that the fstatvfs() routine is available. + +=item C<d_fsync> + +From F<d_fsync.U>: + +This variable conditionally defines the C<HAS_FSYNC> symbol, which +indicates to the C program that the fsync() routine is available. + +=item C<d_ftello> + +From F<d_ftello.U>: + +This variable conditionally defines the C<HAS_FTELLO> symbol, which +indicates to the C program that the ftello() routine is available. + +=item C<d_ftime> + +From F<d_ftime.U>: + +This variable conditionally defines the C<HAS_FTIME> symbol, which indicates +that the ftime() routine exists. The ftime() routine is basically +a sub-second accuracy clock. + +=item C<d_futimes> + +From F<d_futimes.U>: + +This variable conditionally defines the C<HAS_FUTIMES> symbol, which +indicates to the C program that the futimes() routine is available. + +=item C<d_gai_strerror> + +From F<d_gai_strerror.U>: + +This variable conditionally defines the C<HAS_GAI_STRERROR> symbol +if the gai_strerror() routine is available and can be used to +translate error codes returned by getaddrinfo() into human +readable strings. + +=item C<d_Gconvert> + +From F<d_gconvert.U>: + +This variable holds what Gconvert is defined as to convert +floating point numbers into strings. By default, Configure +sets C<this> macro to use the first of gconvert, gcvt, or sprintf +that pass sprintf-%g-like behavior tests. If perl is using +long doubles, the macro uses the first of the following +functions that pass Configure's tests: qgcvt, sprintf (if +Configure knows how to make sprintf format long doubles--see +sPRIgldbl), gconvert, gcvt, and sprintf (casting to double). +The gconvert_preference and gconvert_ld_preference variables +can be used to alter Configure's preferences, for doubles and +long doubles, respectively. If present, they contain a +space-separated list of one or more of the above function +names in the order they should be tried. + +d_Gconvert may be set to override Configure with a platform- +specific function. If this function expects a double, a +different value may need to be set by the F<uselongdouble.cbu> +call-back unit so that long doubles can be formatted without +loss of precision. + +=item C<d_gdbm_ndbm_h_uses_prototypes> + +From F<i_ndbm.U>: + +This variable conditionally defines the C<NDBM_H_USES_PROTOTYPES> symbol, +which indicates that the gdbm-F<ndbm.h> include file uses real C<ANSI> C +prototypes instead of K&R style function declarations. K&R style +declarations are unsupported in C++, so the include file requires +special handling when using a C++ compiler and this variable is +undefined. Consult the different d_*ndbm_h_uses_prototypes variables +to get the same information for alternative F<ndbm.h> include files. + +=item C<d_gdbmndbm_h_uses_prototypes> + +From F<i_ndbm.U>: + +This variable conditionally defines the C<NDBM_H_USES_PROTOTYPES> symbol, +which indicates that the F<gdbm/ndbm.h> include file uses real C<ANSI> C +prototypes instead of K&R style function declarations. K&R style +declarations are unsupported in C++, so the include file requires +special handling when using a C++ compiler and this variable is +undefined. Consult the different d_*ndbm_h_uses_prototypes variables +to get the same information for alternative F<ndbm.h> include files. + +=item C<d_getaddrinfo> + +From F<d_getaddrinfo.U>: + +This variable conditionally defines the C<HAS_GETADDRINFO> symbol, +which indicates to the C program that the getaddrinfo() function +is available. + +=item C<d_getcwd> + +From F<d_getcwd.U>: + +This variable conditionally defines the C<HAS_GETCWD> symbol, which +indicates to the C program that the getcwd() routine is available +to get the current working directory. + +=item C<d_getenv_preserves_other_thread> + +From F<d_getenv_thread.U>: + +This variable conditionally defines the C<GETENV_PRESERVES_OTHER_THREAD> +symbol, which indicates to the C program that the getenv() system call +does not zap the static buffer in a different thread. + +=item C<d_getespwnam> + +From F<d_getespwnam.U>: + +This variable conditionally defines C<HAS_GETESPWNAM> if getespwnam() is +available to retrieve enhanced (shadow) password entries by name. + +=item C<d_getfsstat> + +From F<d_getfsstat.U>: + +This variable conditionally defines the C<HAS_GETFSSTAT> symbol, which +indicates to the C program that the getfsstat() routine is available. + +=item C<d_getgrent> + +From F<d_getgrent.U>: + +This variable conditionally defines the C<HAS_GETGRENT> symbol, which +indicates to the C program that the getgrent() routine is available +for sequential access of the group database. + +=item C<d_getgrent_r> + +From F<d_getgrent_r.U>: + +This variable conditionally defines the C<HAS_GETGRENT_R> symbol, +which indicates to the C program that the getgrent_r() +routine is available. + +=item C<d_getgrgid_r> + +From F<d_getgrgid_r.U>: + +This variable conditionally defines the C<HAS_GETGRGID_R> symbol, +which indicates to the C program that the getgrgid_r() +routine is available. + +=item C<d_getgrnam_r> + +From F<d_getgrnam_r.U>: + +This variable conditionally defines the C<HAS_GETGRNAM_R> symbol, +which indicates to the C program that the getgrnam_r() +routine is available. + +=item C<d_getgrps> + +From F<d_getgrps.U>: + +This variable conditionally defines the C<HAS_GETGROUPS> symbol, which +indicates to the C program that the getgroups() routine is available +to get the list of process groups. + +=item C<d_gethbyaddr> + +From F<d_gethbyad.U>: + +This variable conditionally defines the C<HAS_GETHOSTBYADDR> symbol, which +indicates to the C program that the gethostbyaddr() routine is available +to look up hosts by their C<IP> addresses. + +=item C<d_gethbyname> + +From F<d_gethbynm.U>: + +This variable conditionally defines the C<HAS_GETHOSTBYNAME> symbol, which +indicates to the C program that the gethostbyname() routine is available +to look up host names in some data base or other. + +=item C<d_gethent> + +From F<d_gethent.U>: + +This variable conditionally defines C<HAS_GETHOSTENT> if gethostent() is +available to look up host names in some data base or another. + +=item C<d_gethname> + +From F<d_gethname.U>: + +This variable conditionally defines the C<HAS_GETHOSTNAME> symbol, which +indicates to the C program that the gethostname() routine may be +used to derive the host name. + +=item C<d_gethostbyaddr_r> + +From F<d_gethostbyaddr_r.U>: + +This variable conditionally defines the C<HAS_GETHOSTBYADDR_R> symbol, +which indicates to the C program that the gethostbyaddr_r() +routine is available. + +=item C<d_gethostbyname_r> + +From F<d_gethostbyname_r.U>: + +This variable conditionally defines the C<HAS_GETHOSTBYNAME_R> symbol, +which indicates to the C program that the gethostbyname_r() +routine is available. + +=item C<d_gethostent_r> + +From F<d_gethostent_r.U>: + +This variable conditionally defines the C<HAS_GETHOSTENT_R> symbol, +which indicates to the C program that the gethostent_r() +routine is available. + +=item C<d_gethostprotos> + +From F<d_gethostprotos.U>: + +This variable conditionally defines the C<HAS_GETHOST_PROTOS> symbol, +which indicates to the C program that <netdb.h> supplies +prototypes for the various gethost*() functions. +See also F<netdbtype.U> for probing for various netdb types. + +=item C<d_getitimer> + +From F<d_getitimer.U>: + +This variable conditionally defines the C<HAS_GETITIMER> symbol, which +indicates to the C program that the getitimer() routine is available. + +=item C<d_getlogin> + +From F<d_getlogin.U>: + +This variable conditionally defines the C<HAS_GETLOGIN> symbol, which +indicates to the C program that the getlogin() routine is available +to get the login name. + +=item C<d_getlogin_r> + +From F<d_getlogin_r.U>: + +This variable conditionally defines the C<HAS_GETLOGIN_R> symbol, +which indicates to the C program that the getlogin_r() +routine is available. + +=item C<d_getmnt> + +From F<d_getmnt.U>: + +This variable conditionally defines the C<HAS_GETMNT> symbol, which +indicates to the C program that the getmnt() routine is available +to retrieve one or more mount info blocks by filename. + +=item C<d_getmntent> + +From F<d_getmntent.U>: + +This variable conditionally defines the C<HAS_GETMNTENT> symbol, which +indicates to the C program that the getmntent() routine is available +to iterate through mounted files to get their mount info. + +=item C<d_getnameinfo> + +From F<d_getnameinfo.U>: + +This variable conditionally defines the C<HAS_GETNAMEINFO> symbol, +which indicates to the C program that the getnameinfo() function +is available. + +=item C<d_getnbyaddr> + +From F<d_getnbyad.U>: + +This variable conditionally defines the C<HAS_GETNETBYADDR> symbol, which +indicates to the C program that the getnetbyaddr() routine is available +to look up networks by their C<IP> addresses. + +=item C<d_getnbyname> + +From F<d_getnbynm.U>: + +This variable conditionally defines the C<HAS_GETNETBYNAME> symbol, which +indicates to the C program that the getnetbyname() routine is available +to look up networks by their names. + +=item C<d_getnent> + +From F<d_getnent.U>: + +This variable conditionally defines C<HAS_GETNETENT> if getnetent() is +available to look up network names in some data base or another. + +=item C<d_getnetbyaddr_r> + +From F<d_getnetbyaddr_r.U>: + +This variable conditionally defines the C<HAS_GETNETBYADDR_R> symbol, +which indicates to the C program that the getnetbyaddr_r() +routine is available. + +=item C<d_getnetbyname_r> + +From F<d_getnetbyname_r.U>: + +This variable conditionally defines the C<HAS_GETNETBYNAME_R> symbol, +which indicates to the C program that the getnetbyname_r() +routine is available. + +=item C<d_getnetent_r> + +From F<d_getnetent_r.U>: + +This variable conditionally defines the C<HAS_GETNETENT_R> symbol, +which indicates to the C program that the getnetent_r() +routine is available. + +=item C<d_getnetprotos> + +From F<d_getnetprotos.U>: + +This variable conditionally defines the C<HAS_GETNET_PROTOS> symbol, +which indicates to the C program that <netdb.h> supplies +prototypes for the various getnet*() functions. +See also F<netdbtype.U> for probing for various netdb types. + +=item C<d_getpagsz> + +From F<d_getpagsz.U>: + +This variable conditionally defines C<HAS_GETPAGESIZE> if getpagesize() +is available to get the system page size. + +=item C<d_getpbyname> + +From F<d_getprotby.U>: + +This variable conditionally defines the C<HAS_GETPROTOBYNAME> +symbol, which indicates to the C program that the +getprotobyname() routine is available to look up protocols +by their name. + +=item C<d_getpbynumber> + +From F<d_getprotby.U>: + +This variable conditionally defines the C<HAS_GETPROTOBYNUMBER> +symbol, which indicates to the C program that the +getprotobynumber() routine is available to look up protocols +by their number. + +=item C<d_getpent> + +From F<d_getpent.U>: + +This variable conditionally defines C<HAS_GETPROTOENT> if getprotoent() is +available to look up protocols in some data base or another. + +=item C<d_getpgid> + +From F<d_getpgid.U>: + +This variable conditionally defines the C<HAS_GETPGID> symbol, which +indicates to the C program that the getpgid(pid) function +is available to get the process group id. + +=item C<d_getpgrp> + +From F<d_getpgrp.U>: + +This variable conditionally defines C<HAS_GETPGRP> if getpgrp() is +available to get the current process group. + +=item C<d_getpgrp2> + +From F<d_getpgrp2.U>: + +This variable conditionally defines the HAS_GETPGRP2 symbol, which +indicates to the C program that the getpgrp2() (as in F<DG/C<UX>>) routine +is available to get the current process group. + +=item C<d_getppid> + +From F<d_getppid.U>: + +This variable conditionally defines the C<HAS_GETPPID> symbol, which +indicates to the C program that the getppid() routine is available +to get the parent process C<ID>. + +=item C<d_getprior> + +From F<d_getprior.U>: + +This variable conditionally defines C<HAS_GETPRIORITY> if getpriority() +is available to get a process's priority. + +=item C<d_getprotobyname_r> + +From F<d_getprotobyname_r.U>: + +This variable conditionally defines the C<HAS_GETPROTOBYNAME_R> symbol, +which indicates to the C program that the getprotobyname_r() +routine is available. + +=item C<d_getprotobynumber_r> + +From F<d_getprotobynumber_r.U>: + +This variable conditionally defines the C<HAS_GETPROTOBYNUMBER_R> symbol, +which indicates to the C program that the getprotobynumber_r() +routine is available. + +=item C<d_getprotoent_r> + +From F<d_getprotoent_r.U>: + +This variable conditionally defines the C<HAS_GETPROTOENT_R> symbol, +which indicates to the C program that the getprotoent_r() +routine is available. + +=item C<d_getprotoprotos> + +From F<d_getprotoprotos.U>: + +This variable conditionally defines the C<HAS_GETPROTO_PROTOS> symbol, +which indicates to the C program that <netdb.h> supplies +prototypes for the various getproto*() functions. +See also F<netdbtype.U> for probing for various netdb types. + +=item C<d_getprpwnam> + +From F<d_getprpwnam.U>: + +This variable conditionally defines C<HAS_GETPRPWNAM> if getprpwnam() is +available to retrieve protected (shadow) password entries by name. + +=item C<d_getpwent> + +From F<d_getpwent.U>: + +This variable conditionally defines the C<HAS_GETPWENT> symbol, which +indicates to the C program that the getpwent() routine is available +for sequential access of the passwd database. + +=item C<d_getpwent_r> + +From F<d_getpwent_r.U>: + +This variable conditionally defines the C<HAS_GETPWENT_R> symbol, +which indicates to the C program that the getpwent_r() +routine is available. + +=item C<d_getpwnam_r> + +From F<d_getpwnam_r.U>: + +This variable conditionally defines the C<HAS_GETPWNAM_R> symbol, +which indicates to the C program that the getpwnam_r() +routine is available. + +=item C<d_getpwuid_r> + +From F<d_getpwuid_r.U>: + +This variable conditionally defines the C<HAS_GETPWUID_R> symbol, +which indicates to the C program that the getpwuid_r() +routine is available. + +=item C<d_getsbyname> + +From F<d_getsrvby.U>: + +This variable conditionally defines the C<HAS_GETSERVBYNAME> +symbol, which indicates to the C program that the +getservbyname() routine is available to look up services +by their name. + +=item C<d_getsbyport> + +From F<d_getsrvby.U>: + +This variable conditionally defines the C<HAS_GETSERVBYPORT> +symbol, which indicates to the C program that the +getservbyport() routine is available to look up services +by their port. + +=item C<d_getsent> + +From F<d_getsent.U>: + +This variable conditionally defines C<HAS_GETSERVENT> if getservent() is +available to look up network services in some data base or another. + +=item C<d_getservbyname_r> + +From F<d_getservbyname_r.U>: + +This variable conditionally defines the C<HAS_GETSERVBYNAME_R> symbol, +which indicates to the C program that the getservbyname_r() +routine is available. + +=item C<d_getservbyport_r> + +From F<d_getservbyport_r.U>: + +This variable conditionally defines the C<HAS_GETSERVBYPORT_R> symbol, +which indicates to the C program that the getservbyport_r() +routine is available. + +=item C<d_getservent_r> + +From F<d_getservent_r.U>: + +This variable conditionally defines the C<HAS_GETSERVENT_R> symbol, +which indicates to the C program that the getservent_r() +routine is available. + +=item C<d_getservprotos> + +From F<d_getservprotos.U>: + +This variable conditionally defines the C<HAS_GETSERV_PROTOS> symbol, +which indicates to the C program that <netdb.h> supplies +prototypes for the various getserv*() functions. +See also F<netdbtype.U> for probing for various netdb types. + +=item C<d_getspnam> + +From F<d_getspnam.U>: + +This variable conditionally defines C<HAS_GETSPNAM> if getspnam() is +available to retrieve SysV shadow password entries by name. + +=item C<d_getspnam_r> + +From F<d_getspnam_r.U>: + +This variable conditionally defines the C<HAS_GETSPNAM_R> symbol, +which indicates to the C program that the getspnam_r() +routine is available. + +=item C<d_gettimeod> + +From F<d_ftime.U>: + +This variable conditionally defines the C<HAS_GETTIMEOFDAY> symbol, which +indicates that the gettimeofday() system call exists (to obtain a +sub-second accuracy clock). You should probably include <sys/resource.h>. + +=item C<d_gmtime64> + +From F<d_timefuncs64.U>: + +This variable conditionally defines the HAS_GMTIME64 symbol, which +indicates to the C program that the gmtime64 () routine is available. + +=item C<d_gmtime_r> + +From F<d_gmtime_r.U>: + +This variable conditionally defines the C<HAS_GMTIME_R> symbol, +which indicates to the C program that the gmtime_r() +routine is available. + +=item C<d_gnulibc> + +From F<d_gnulibc.U>: + +Defined if we're dealing with the C<GNU> C Library. + +=item C<d_grpasswd> + +From F<i_grp.U>: + +This variable conditionally defines C<GRPASSWD>, which indicates +that struct group in <grp.h> contains gr_passwd. + +=item C<d_has_C_UTF8> + +From F<d_setlocale.U>: + +This variable is set to either C<true> or C<false> depending on +whether the compilation system supports the F<C.UTF>-8 locale. + +=item C<d_hasmntopt> + +From F<d_hasmntopt.U>: + +This variable conditionally defines the C<HAS_HASMNTOPT> symbol, which +indicates to the C program that the hasmntopt() routine is available +to query the mount options of file systems. + +=item C<d_htonl> + +From F<d_htonl.U>: + +This variable conditionally defines C<HAS_HTONL> if htonl() and its +friends are available to do network order byte swapping. + +=item C<d_hypot> + +From F<d_hypot.U>: + +This variable conditionally defines C<HAS_HYPOT> if hypot is available +for numerically stable hypotenuse function. + +=item C<d_ilogb> + +From F<d_ilogb.U>: + +This variable conditionally defines the C<HAS_ILOGB> symbol, which +indicates to the C program that the ilogb() routine is available +for extracting the exponent of double x as a signed integer. + +=item C<d_ilogbl> + +From F<d_ilogbl.U>: + +This variable conditionally defines the C<HAS_ILOGBL> symbol, which +indicates to the C program that the ilogbl() routine is available +for extracting the exponent of long double x as a signed integer. +If scalbnl is also present we can emulate frexpl. + +=item C<d_inc_version_list> + +From F<inc_version_list.U>: + +This variable conditionally defines C<PERL_INC_VERSION_LIST>. +It is set to undef when C<PERL_INC_VERSION_LIST> is empty. + +=item C<d_inetaton> + +From F<d_inetaton.U>: + +This variable conditionally defines the C<HAS_INET_ATON> symbol, which +indicates to the C program that the inet_aton() function is available +to parse C<IP> address C<dotted-quad> strings. + +=item C<d_inetntop> + +From F<d_inetntop.U>: + +This variable conditionally defines the C<HAS_INETNTOP> symbol, +which indicates to the C program that the inet_ntop() function +is available. + +=item C<d_inetpton> + +From F<d_inetpton.U>: + +This variable conditionally defines the C<HAS_INETPTON> symbol, +which indicates to the C program that the inet_pton() function +is available. + +=item C<d_int64_t> + +From F<d_int64_t.U>: + +This symbol will be defined if the C compiler supports int64_t. + +=item C<d_ip_mreq> + +From F<d_socket.U>: + +This variable conditionally defines the C<HAS_IP_MREQ> symbol, which +indicates the availability of a struct ip_mreq. + +=item C<d_ip_mreq_source> + +From F<d_socket.U>: + +This variable conditionally defines the C<HAS_IP_MREQ_SOURCE> symbol, +which indicates the availability of a struct ip_mreq_source. + +=item C<d_ipv6_mreq> + +From F<d_socket.U>: + +This variable conditionally defines the HAS_IPV6_MREQ symbol, which +indicates the availability of a struct ipv6_mreq. + +=item C<d_ipv6_mreq_source> + +From F<d_socket.U>: + +This variable conditionally defines the HAS_IPV6_MREQ_SOURCE symbol, +which indicates the availability of a struct ipv6_mreq_source. + +=item C<d_isascii> + +From F<d_isascii.U>: + +This variable conditionally defines the C<HAS_ISASCII> constant, +which indicates to the C program that isascii() is available. + +=item C<d_isblank> + +From F<d_isblank.U>: + +This variable conditionally defines the C<HAS_ISBLANK> constant, +which indicates to the C program that isblank() is available. + +=item C<d_isfinite> + +From F<d_isfinite.U>: + +This variable conditionally defines the C<HAS_ISFINITE> symbol, which +indicates to the C program that the isfinite() routine is available. + +=item C<d_isfinitel> + +From F<d_isfinitel.U>: + +This variable conditionally defines the C<HAS_ISFINITEL> symbol, which +indicates to the C program that the isfinitel() routine is available. + +=item C<d_isinf> + +From F<d_isinf.U>: + +This variable conditionally defines the C<HAS_ISINF> symbol, which +indicates to the C program that the isinf() routine is available. + +=item C<d_isinfl> + +From F<d_isinfl.U>: + +This variable conditionally defines the C<HAS_ISINFL> symbol, which +indicates to the C program that the isinfl() routine is available. + +=item C<d_isless> + +From F<d_isless.U>: + +This variable conditionally defines the C<HAS_ISLESS> symbol, which +indicates to the C program that the isless() routine is available. + +=item C<d_isnan> + +From F<d_isnan.U>: + +This variable conditionally defines the C<HAS_ISNAN> symbol, which +indicates to the C program that the isnan() routine is available. + +=item C<d_isnanl> + +From F<d_isnanl.U>: + +This variable conditionally defines the C<HAS_ISNANL> symbol, which +indicates to the C program that the isnanl() routine is available. + +=item C<d_isnormal> + +From F<d_isnormal.U>: + +This variable conditionally defines the C<HAS_ISNORMAL> symbol, which +indicates to the C program that the isnormal() routine is available. + +=item C<d_j0> + +From F<d_j0.U>: + +This variable conditionally defines the HAS_J0 symbol, which +indicates to the C program that the j0() routine is available. + +=item C<d_j0l> + +From F<d_j0.U>: + +This variable conditionally defines the HAS_J0L symbol, which +indicates to the C program that the j0l() routine is available. + +=item C<d_killpg> + +From F<d_killpg.U>: + +This variable conditionally defines the C<HAS_KILLPG> symbol, which +indicates to the C program that the killpg() routine is available +to kill process groups. + +=item C<d_lc_monetary_2008> + +From F<d_lc_monetary_2008.U>: + +This variable conditionally defines HAS_LC_MONETARY_2008 if libc +has the international currency locale rules from C<POSIX> +1003.1-2008. + +=item C<d_lchown> + +From F<d_lchown.U>: + +This variable conditionally defines the C<HAS_LCHOWN> symbol, which +indicates to the C program that the lchown() routine is available +to operate on a symbolic link (instead of following the link). + +=item C<d_ldbl_dig> + +From F<d_ldbl_dig.U>: + +This variable conditionally defines d_ldbl_dig if this system's +header files provide C<LDBL_DIG>, which is the number of significant +digits in a long double precision number. + +=item C<d_ldexpl> + +From F<d_longdbl.U>: + +This variable conditionally defines the C<HAS_LDEXPL> symbol, which +indicates to the C program that the ldexpl() routine is available. + +=item C<d_lgamma> + +From F<d_lgamma.U>: + +This variable conditionally defines the C<HAS_LGAMMA> symbol, which +indicates to the C program that the lgamma() routine is available +for the log gamma function. See also d_tgamma and d_lgamma_r. + +=item C<d_lgamma_r> + +From F<d_lgamma_r.U>: + +This variable conditionally defines the C<HAS_LGAMMA_R> symbol, which +indicates to the C program that the lgamma_r() routine is available +for the log gamma function, without using the global signgam variable. + +=item C<d_libm_lib_version> + +From F<d_libm_lib_version.U>: + +This variable conditionally defines the C<LIBM_LIB_VERSION> symbol, +which indicates to the C program that F<math.h> defines C<_LIB_VERSION> +being available in libm + +=item C<d_libname_unique> + +From F<so.U>: + +This variable is defined if the target system insists on unique +basenames for shared library files. This is currently true on Android, +false everywhere else we know of. +Defaults to C<undef>. + +=item C<d_link> + +From F<d_link.U>: + +This variable conditionally defines C<HAS_LINK> if link() is +available to create hard links. + +=item C<d_linkat> + +From F<d_fsat.U>: + +This variable conditionally defines the C<HAS_LINKAT> symbol, which +indicates the C<POSIX> linkat() function is available. + +=item C<d_llrint> + +From F<d_llrint.U>: + +This variable conditionally defines the C<HAS_LLRINT> symbol, which +indicates to the C program that the llrint() routine is available +to return the long long value closest to a double (according +to the current rounding mode). + +=item C<d_llrintl> + +From F<d_llrintl.U>: + +This variable conditionally defines the C<HAS_LLRINTL> symbol, which +indicates to the C program that the llrintl() routine is available +to return the long long value closest to a long double (according +to the current rounding mode). + +=item C<d_llround> + +From F<d_llround.U>: + +This variable conditionally defines the C<HAS_LLROUND> symbol, which +indicates to the C program that the llround() routine is available +to return the long long value nearest to x. + +=item C<d_llroundl> + +From F<d_llroundl.U>: + +This variable conditionally defines the C<HAS_LLROUNDL> symbol, which +indicates to the C program that the llroundl() routine is available +to return the long long value nearest to x away from zero. + +=item C<d_localeconv_l> + +From F<d_localeconv_l.U>: + +This variable conditionally defines the C<HAS_LOCALECONV_L> symbol, which +indicates to the C program that the localeconv_l() routine is available. + +=item C<d_localtime64> + +From F<d_timefuncs64.U>: + +This variable conditionally defines the HAS_LOCALTIME64 symbol, which +indicates to the C program that the localtime64 () routine is available. + +=item C<d_localtime_r> + +From F<d_localtime_r.U>: + +This variable conditionally defines the C<HAS_LOCALTIME_R> symbol, +which indicates to the C program that the localtime_r() +routine is available. + +=item C<d_localtime_r_needs_tzset> + +From F<d_localtime_r.U>: + +This variable conditionally defines the C<LOCALTIME_R_NEEDS_TZSET> +symbol, which makes us call tzset before localtime_r() + +=item C<d_locconv> + +From F<d_locconv.U>: + +This variable conditionally defines C<HAS_LOCALECONV> if localeconv() is +available for numeric and monetary formatting conventions. + +=item C<d_lockf> + +From F<d_lockf.U>: + +This variable conditionally defines C<HAS_LOCKF> if lockf() is +available to do file locking. + +=item C<d_log1p> + +From F<d_log1p.U>: + +This variable conditionally defines the HAS_LOG1P symbol, which +indicates to the C program that the logp1() routine is available +to compute log(1 + x) for values of x close to zero. + +=item C<d_log2> + +From F<d_log2.U>: + +This variable conditionally defines the HAS_LOG2 symbol, which +indicates to the C program that the log2() routine is available +to compute log base two. + +=item C<d_logb> + +From F<d_logb.U>: + +This variable conditionally defines the C<HAS_LOGB> symbol, which +indicates to the C program that the logb() routine is available +to extract the exponent of x. + +=item C<d_long_double_style_ieee> + +From F<d_longdbl.U>: + +This variable conditionally defines C<LONG_DOUBLE_STYLE_IEEE> +if the long double is any of the C<IEEE> 754 style long doubles: +C<LONG_DOUBLE_STYLE_IEEE_STD>, C<LONG_DOUBLE_STYLE_IEEE_EXTENDED>, +C<LONG_DOUBLE_STYLE_IEEE_DOUBLEDOUBLE>. + +=item C<d_long_double_style_ieee_doubledouble> + +From F<d_longdbl.U>: + +This variable conditionally defines C<LONG_DOUBLE_STYLE_IEEE_DOUBLEDOUBLE> +if the long double is the 128-bit C<IEEE> 754 double-double. + +=item C<d_long_double_style_ieee_extended> + +From F<d_longdbl.U>: + +This variable conditionally defines C<LONG_DOUBLE_STYLE_IEEE_EXTENDED> +if the long double is the 80-bit C<IEEE> 754 extended precision. +Note that despite the C<extended> this is less than the C<std>, +since this is an extension of the double precision. + +=item C<d_long_double_style_ieee_std> + +From F<d_longdbl.U>: + +This variable conditionally defines C<LONG_DOUBLE_STYLE_IEEE_STD> +if the long double is the 128-bit C<IEEE> 754. + +=item C<d_long_double_style_vax> + +From F<d_longdbl.U>: + +This variable conditionally defines C<LONG_DOUBLE_STYLE_VAX> +if the long double is the 128-bit C<VAX> format H. + +=item C<d_longdbl> + +From F<d_longdbl.U>: + +This variable conditionally defines C<HAS_LONG_DOUBLE> if +the long double type is supported. + +=item C<d_longlong> + +From F<d_longlong.U>: + +This variable conditionally defines C<HAS_LONG_LONG> if +the long long type is supported. + +=item C<d_lrint> + +From F<d_lrint.U>: + +This variable conditionally defines the C<HAS_LRINT> symbol, which +indicates to the C program that the lrint() routine is available +to return the integral value closest to a double (according +to the current rounding mode). + +=item C<d_lrintl> + +From F<d_lrintl.U>: + +This variable conditionally defines the C<HAS_LRINTL> symbol, which +indicates to the C program that the lrintl() routine is available +to return the integral value closest to a long double (according +to the current rounding mode). + +=item C<d_lround> + +From F<d_lround.U>: + +This variable conditionally defines the C<HAS_LROUND> symbol, which +indicates to the C program that the lround() routine is available +to return the integral value nearest to x. + +=item C<d_lroundl> + +From F<d_lroundl.U>: + +This variable conditionally defines the C<HAS_LROUNDL> symbol, which +indicates to the C program that the lroundl() routine is available +to return the integral value nearest to x away from zero. + +=item C<d_lseekproto> + +From F<d_lseekproto.U>: + +This variable conditionally defines the C<HAS_LSEEK_PROTO> symbol, +which indicates to the C program that the system provides +a prototype for the lseek() function. Otherwise, it is +up to the program to supply one. + +=item C<d_lstat> + +From F<d_lstat.U>: + +This variable conditionally defines C<HAS_LSTAT> if lstat() is +available to do file stats on symbolic links. + +=item C<d_madvise> + +From F<d_madvise.U>: + +This variable conditionally defines C<HAS_MADVISE> if madvise() is +available to map a file into memory. + +=item C<d_malloc_good_size> + +From F<d_malloc_size.U>: + +This symbol, if defined, indicates that the malloc_good_size +routine is available for use. + +=item C<d_malloc_size> + +From F<d_malloc_size.U>: + +This symbol, if defined, indicates that the malloc_size +routine is available for use. + +=item C<d_malloc_usable_size> + +From F<d_malloc_size.U>: + +This symbol, if defined, indicates that the malloc_usable_size +routine is available for use. + +=item C<d_mblen> + +From F<d_mblen.U>: + +This variable conditionally defines the C<HAS_MBLEN> symbol, which +indicates to the C program that the mblen() routine is available +to find the number of bytes in a multibyte character. + +=item C<d_mbrlen> + +From F<d_mbrlen.U>: + +This variable conditionally defines the C<HAS_MBRLEN> symbol if the +mbrlen() routine is available to be used to get the length of +multi-byte character strings. + +=item C<d_mbrtowc> + +From F<d_mbrtowc.U>: + +This variable conditionally defines the C<HAS_MBRTOWC> symbol if the +mbrtowc() routine is available to be used to convert a multi-byte +character into a wide character. + +=item C<d_mbstowcs> + +From F<d_mbstowcs.U>: + +This variable conditionally defines the C<HAS_MBSTOWCS> symbol, which +indicates to the C program that the mbstowcs() routine is available +to convert a multibyte string into a wide character string. + +=item C<d_mbtowc> + +From F<d_mbtowc.U>: + +This variable conditionally defines the C<HAS_MBTOWC> symbol, which +indicates to the C program that the mbtowc() routine is available +to convert multibyte to a wide character. + +=item C<d_memmem> + +From F<d_memmem.U>: + +This variable conditionally defines the C<HAS_MEMMEM> symbol, which +indicates to the C program that the memmem() routine is available +to return a pointer to the start of the first occurrence of a +substring in a memory area (or C<NULL> if not found). + +=item C<d_memrchr> + +From F<d_memrchr.U>: + +This variable conditionally defines the C<HAS_MEMRCHR> symbol, which +indicates to the C program that the memrchr() routine is available +to return a pointer to the last occurrence of a byte in a memory +area (or C<NULL> if not found). + +=item C<d_mkdir> + +From F<d_mkdir.U>: + +This variable conditionally defines the C<HAS_MKDIR> symbol, which +indicates to the C program that the mkdir() routine is available +to create F<directories.>. + +=item C<d_mkdtemp> + +From F<d_mkdtemp.U>: + +This variable conditionally defines the C<HAS_MKDTEMP> symbol, which +indicates to the C program that the mkdtemp() routine is available +to exclusively create a uniquely named temporary directory. + +=item C<d_mkfifo> + +From F<d_mkfifo.U>: + +This variable conditionally defines the C<HAS_MKFIFO> symbol, which +indicates to the C program that the mkfifo() routine is available. + +=item C<d_mkostemp> + +From F<d_mkostemp.U>: + +This variable conditionally defines C<HAS_MKOSTEMP> if mkostemp() is +available to exclusively create and open a uniquely named (with a +suffix) temporary file. + +=item C<d_mkstemp> + +From F<d_mkstemp.U>: + +This variable conditionally defines the C<HAS_MKSTEMP> symbol, which +indicates to the C program that the mkstemp() routine is available +to exclusively create and open a uniquely named temporary file. + +=item C<d_mkstemps> + +From F<d_mkstemps.U>: + +This variable conditionally defines the C<HAS_MKSTEMPS> symbol, which +indicates to the C program that the mkstemps() routine is available +to exclusively create and open a uniquely named (with a suffix) +temporary file. + +=item C<d_mktime> + +From F<d_mktime.U>: + +This variable conditionally defines the C<HAS_MKTIME> symbol, which +indicates to the C program that the mktime() routine is available. + +=item C<d_mktime64> + +From F<d_timefuncs64.U>: + +This variable conditionally defines the HAS_MKTIME64 symbol, which +indicates to the C program that the mktime64 () routine is available. + +=item C<d_mmap> + +From F<d_mmap.U>: + +This variable conditionally defines C<HAS_MMAP> if mmap() is +available to map a file into memory. + +=item C<d_modfl> + +From F<d_modfl.U>: + +This variable conditionally defines the C<HAS_MODFL> symbol, which +indicates to the C program that the modfl() routine is available. + +=item C<d_modflproto> + +From F<d_modfl.U>: + +This symbol, if defined, indicates that the system provides +a prototype for the modfl() function. Otherwise, it is up +to the program to supply one. C99 says it should be +long double modfl(long double, long double *); + +=item C<d_mprotect> + +From F<d_mprotect.U>: + +This variable conditionally defines C<HAS_MPROTECT> if mprotect() is +available to modify the access protection of a memory mapped file. + +=item C<d_msg> + +From F<d_msg.U>: + +This variable conditionally defines the C<HAS_MSG> symbol, which +indicates that the entire msg*(2) library is present. + +=item C<d_msg_ctrunc> + +From F<d_socket.U>: + +This variable conditionally defines the C<HAS_MSG_CTRUNC> symbol, +which indicates that the C<MSG_CTRUNC> is available. #ifdef is +not enough because it may be an enum, glibc has been known to do this. + +=item C<d_msg_dontroute> + +From F<d_socket.U>: + +This variable conditionally defines the C<HAS_MSG_DONTROUTE> symbol, +which indicates that the C<MSG_DONTROUTE> is available. #ifdef is +not enough because it may be an enum, glibc has been known to do this. + +=item C<d_msg_oob> + +From F<d_socket.U>: + +This variable conditionally defines the C<HAS_MSG_OOB> symbol, +which indicates that the C<MSG_OOB> is available. #ifdef is +not enough because it may be an enum, glibc has been known to do this. + +=item C<d_msg_peek> + +From F<d_socket.U>: + +This variable conditionally defines the C<HAS_MSG_PEEK> symbol, +which indicates that the C<MSG_PEEK> is available. #ifdef is +not enough because it may be an enum, glibc has been known to do this. + +=item C<d_msg_proxy> + +From F<d_socket.U>: + +This variable conditionally defines the C<HAS_MSG_PROXY> symbol, +which indicates that the C<MSG_PROXY> is available. #ifdef is +not enough because it may be an enum, glibc has been known to do this. + +=item C<d_msgctl> + +From F<d_msgctl.U>: + +This variable conditionally defines the C<HAS_MSGCTL> symbol, which +indicates to the C program that the msgctl() routine is available. + +=item C<d_msgget> + +From F<d_msgget.U>: + +This variable conditionally defines the C<HAS_MSGGET> symbol, which +indicates to the C program that the msgget() routine is available. + +=item C<d_msghdr_s> + +From F<d_msghdr_s.U>: + +This variable conditionally defines the C<HAS_STRUCT_MSGHDR> symbol, +which indicates that the struct msghdr is supported. + +=item C<d_msgrcv> + +From F<d_msgrcv.U>: + +This variable conditionally defines the C<HAS_MSGRCV> symbol, which +indicates to the C program that the msgrcv() routine is available. + +=item C<d_msgsnd> + +From F<d_msgsnd.U>: + +This variable conditionally defines the C<HAS_MSGSND> symbol, which +indicates to the C program that the msgsnd() routine is available. + +=item C<d_msync> + +From F<d_msync.U>: + +This variable conditionally defines C<HAS_MSYNC> if msync() is +available to synchronize a mapped file. + +=item C<d_munmap> + +From F<d_munmap.U>: + +This variable conditionally defines C<HAS_MUNMAP> if munmap() is +available to unmap a region mapped by mmap(). + +=item C<d_mymalloc> + +From F<mallocsrc.U>: + +This variable conditionally defines C<MYMALLOC> in case other parts +of the source want to take special action if C<MYMALLOC> is used. +This may include different sorts of profiling or error detection. + +=item C<d_nan> + +From F<d_nan.U>: + +This variable conditionally defines C<HAS_NAN> if nan() is +available to generate NaN. + +=item C<d_nanosleep> + +From F<d_nanosleep.U>: + +This variable conditionally defines C<HAS_NANOSLEEP> +if nanosleep() is available to sleep with 1E-9 sec accuracy. + +=item C<d_ndbm> + +From F<i_ndbm.U>: + +This variable conditionally defines the C<HAS_NDBM> symbol, which +indicates that both the F<ndbm.h> include file and an appropriate ndbm +library exist. Consult the different i_*ndbm variables +to find out the actual include location. Sometimes, a system has the +header file but not the library. This variable will only be set if +the system has both. + +=item C<d_ndbm_h_uses_prototypes> + +From F<i_ndbm.U>: + +This variable conditionally defines the C<NDBM_H_USES_PROTOTYPES> symbol, +which indicates that the F<ndbm.h> include file uses real C<ANSI> C +prototypes instead of K&R style function declarations. K&R style +declarations are unsupported in C++, so the include file requires +special handling when using a C++ compiler and this variable is +undefined. Consult the different d_*ndbm_h_uses_prototypes variables +to get the same information for alternative F<ndbm.h> include files. + +=item C<d_nearbyint> + +From F<d_nearbyint.U>: + +This variable conditionally defines C<HAS_NEARBYINT> if nearbyint() +is available to return the integral value closest to (according to +the current rounding mode) to x. + +=item C<d_newlocale> + +From F<d_newlocale.U>: + +This variable conditionally defines the C<HAS_NEWLOCALE> symbol, which +indicates to the C program that the newlocale() routine is available +to return a new locale object or modify an existing locale object. + +=item C<d_nextafter> + +From F<d_nextafter.U>: + +This variable conditionally defines C<HAS_NEXTAFTER> if nextafter() +is available to return the next machine representable double from +x in direction y. + +=item C<d_nexttoward> + +From F<d_nexttoward.U>: + +This variable conditionally defines C<HAS_NEXTTOWARD> if nexttoward() +is available to return the next machine representable long double from +x in direction y. + +=item C<d_nice> + +From F<d_nice.U>: + +This variable conditionally defines the C<HAS_NICE> symbol, which +indicates to the C program that the nice() routine is available. + +=item C<d_nl_langinfo> + +From F<d_nl_langinfo.U>: + +This variable conditionally defines the C<HAS_NL_LANGINFO> symbol, which +indicates to the C program that the nl_langinfo() routine is available. + +=item C<d_nv_preserves_uv> + +From F<perlxv.U>: + +This variable indicates whether a variable of type nvtype +can preserve all the bits a variable of type uvtype. + +=item C<d_nv_zero_is_allbits_zero> + +From F<perlxv.U>: + +This variable indicates whether a variable of type nvtype +stores 0.0 in memory as all bits zero. + +=item C<d_off64_t> + +From F<d_off64_t.U>: + +This symbol will be defined if the C compiler supports off64_t. + +=item C<d_old_pthread_create_joinable> + +From F<d_pthrattrj.U>: + +This variable conditionally defines pthread_create_joinable. +undef if F<pthread.h> defines C<PTHREAD_CREATE_JOINABLE>. + +=item C<d_oldpthreads> + +From F<usethreads.U>: + +This variable conditionally defines the C<OLD_PTHREADS_API> symbol, +and indicates that Perl should be built to use the old +draft C<POSIX> threads C<API>. This is only potentially meaningful if +usethreads is set. + +=item C<d_oldsock> + +From F<d_socket.U>: + +This variable conditionally defines the C<OLDSOCKET> symbol, which +indicates that the C<BSD> socket interface is based on 4.1c and not 4.2. + +=item C<d_open3> + +From F<d_open3.U>: + +This variable conditionally defines the HAS_OPEN3 manifest constant, +which indicates to the C program that the 3 argument version of +the open(2) function is available. + +=item C<d_openat> + +From F<d_fsat.U>: + +This variable conditionally defines the C<HAS_OPENAT> symbol, which +indicates the C<POSIX> openat() function is available. + +=item C<d_pathconf> + +From F<d_pathconf.U>: + +This variable conditionally defines the C<HAS_PATHCONF> symbol, which +indicates to the C program that the pathconf() routine is available +to determine file-system related limits and options associated +with a given filename. + +=item C<d_pause> + +From F<d_pause.U>: + +This variable conditionally defines the C<HAS_PAUSE> symbol, which +indicates to the C program that the pause() routine is available +to suspend a process until a signal is received. + +=item C<d_perl_otherlibdirs> + +From F<otherlibdirs.U>: + +This variable conditionally defines C<PERL_OTHERLIBDIRS>, which +contains a colon-separated set of paths for the perl binary to +include in @C<INC>. See also otherlibdirs. + +=item C<d_phostname> + +From F<d_gethname.U>: + +This variable conditionally defines the C<HAS_PHOSTNAME> symbol, which +contains the shell command which, when fed to popen(), may be +used to derive the host name. + +=item C<d_pipe> + +From F<d_pipe.U>: + +This variable conditionally defines the C<HAS_PIPE> symbol, which +indicates to the C program that the pipe() routine is available +to create an inter-process channel. + +=item C<d_pipe2> + +From F<d_pipe2.U>: + +This variable conditionally defines the HAS_PIPE2 symbol, which +indicates to the C program that the pipe2() routine is available +to create an inter-process channel. + +=item C<d_poll> + +From F<d_poll.U>: + +This variable conditionally defines the C<HAS_POLL> symbol, which +indicates to the C program that the poll() routine is available +to poll active file descriptors. + +=item C<d_portable> + +From F<d_portable.U>: + +This variable conditionally defines the C<PORTABLE> symbol, which +indicates to the C program that it should not assume that it is +running on the machine it was compiled on. + +=item C<d_prctl> + +From F<d_prctl.U>: + +This variable conditionally defines the C<HAS_PRCTL> symbol, which +indicates to the C program that the prctl() routine is available. +Note that there are at least two prctl variants: Linux and Irix. +While they are somewhat similar, they are incompatible. + +=item C<d_prctl_set_name> + +From F<d_prctl.U>: + +This variable conditionally defines the C<HAS_PRCTL_SET_NAME> symbol, +which indicates to the C program that the prctl() routine supports +the C<PR_SET_NAME> option. + +=item C<d_PRId64> + +From F<quadfio.U>: + +This variable conditionally defines the PERL_PRId64 symbol, which +indicates that stdio has a symbol to print 64-bit decimal numbers. + +=item C<d_PRIeldbl> + +From F<longdblfio.U>: + +This variable conditionally defines the PERL_PRIfldbl symbol, which +indicates that stdio has a symbol to print long doubles. + +=item C<d_PRIEUldbl> + +From F<longdblfio.U>: + +This variable conditionally defines the PERL_PRIfldbl symbol, which +indicates that stdio has a symbol to print long doubles. +The C<U> in the name is to separate this from d_PRIeldbl so that even +case-blind systems can see the difference. + +=item C<d_PRIfldbl> + +From F<longdblfio.U>: + +This variable conditionally defines the PERL_PRIfldbl symbol, which +indicates that stdio has a symbol to print long doubles. + +=item C<d_PRIFUldbl> + +From F<longdblfio.U>: + +This variable conditionally defines the PERL_PRIfldbl symbol, which +indicates that stdio has a symbol to print long doubles. +The C<U> in the name is to separate this from d_PRIfldbl so that even +case-blind systems can see the difference. + +=item C<d_PRIgldbl> + +From F<longdblfio.U>: + +This variable conditionally defines the PERL_PRIfldbl symbol, which +indicates that stdio has a symbol to print long doubles. + +=item C<d_PRIGUldbl> + +From F<longdblfio.U>: + +This variable conditionally defines the PERL_PRIfldbl symbol, which +indicates that stdio has a symbol to print long doubles. +The C<U> in the name is to separate this from d_PRIgldbl so that even +case-blind systems can see the difference. + +=item C<d_PRIi64> + +From F<quadfio.U>: + +This variable conditionally defines the PERL_PRIi64 symbol, which +indicates that stdio has a symbol to print 64-bit decimal numbers. + +=item C<d_printf_format_null> + +From F<d_attribut.U>: + +This variable conditionally defines C<PRINTF_FORMAT_NULL_OK>, which +indicates the C compiler allows printf-like formats to be null. + +=item C<d_PRIo64> + +From F<quadfio.U>: + +This variable conditionally defines the PERL_PRIo64 symbol, which +indicates that stdio has a symbol to print 64-bit octal numbers. + +=item C<d_PRIu64> + +From F<quadfio.U>: + +This variable conditionally defines the PERL_PRIu64 symbol, which +indicates that stdio has a symbol to print 64-bit unsigned decimal +numbers. + +=item C<d_PRIx64> + +From F<quadfio.U>: + +This variable conditionally defines the PERL_PRIx64 symbol, which +indicates that stdio has a symbol to print 64-bit hexadecimal numbers. + +=item C<d_PRIXU64> + +From F<quadfio.U>: + +This variable conditionally defines the PERL_PRIXU64 symbol, which +indicates that stdio has a symbol to print 64-bit hExADECimAl numbers. +The C<U> in the name is to separate this from d_PRIx64 so that even +case-blind systems can see the difference. + +=item C<d_procselfexe> + +From F<d_procselfexe.U>: + +Defined if $procselfexe is symlink to the absolute +pathname of the executing program. + +=item C<d_pseudofork> + +From F<d_vfork.U>: + +This variable conditionally defines the C<HAS_PSEUDOFORK> symbol, +which indicates that an emulation of the fork routine is available. + +=item C<d_pthread_atfork> + +From F<d_pthread_atfork.U>: + +This variable conditionally defines the C<HAS_PTHREAD_ATFORK> symbol, +which indicates to the C program that the pthread_atfork() +routine is available. + +=item C<d_pthread_attr_setscope> + +From F<d_pthread_attr_ss.U>: + +This variable conditionally defines C<HAS_PTHREAD_ATTR_SETSCOPE> if +pthread_attr_setscope() is available to set the contention scope +attribute of a thread attribute object. + +=item C<d_pthread_yield> + +From F<d_pthread_y.U>: + +This variable conditionally defines the C<HAS_PTHREAD_YIELD> +symbol if the pthread_yield routine is available to yield +the execution of the current thread. + +=item C<d_ptrdiff_t> + +From F<d_ptrdiff_t.U>: + +This symbol will be defined if the C compiler supports ptrdiff_t. + +=item C<d_pwage> + +From F<i_pwd.U>: + +This variable conditionally defines C<PWAGE>, which indicates +that struct passwd contains pw_age. + +=item C<d_pwchange> + +From F<i_pwd.U>: + +This variable conditionally defines C<PWCHANGE>, which indicates +that struct passwd contains pw_change. + +=item C<d_pwclass> + +From F<i_pwd.U>: + +This variable conditionally defines C<PWCLASS>, which indicates +that struct passwd contains pw_class. + +=item C<d_pwcomment> + +From F<i_pwd.U>: + +This variable conditionally defines C<PWCOMMENT>, which indicates +that struct passwd contains pw_comment. + +=item C<d_pwexpire> + +From F<i_pwd.U>: + +This variable conditionally defines C<PWEXPIRE>, which indicates +that struct passwd contains pw_expire. + +=item C<d_pwgecos> + +From F<i_pwd.U>: + +This variable conditionally defines C<PWGECOS>, which indicates +that struct passwd contains pw_gecos. + +=item C<d_pwpasswd> + +From F<i_pwd.U>: + +This variable conditionally defines C<PWPASSWD>, which indicates +that struct passwd contains pw_passwd. + +=item C<d_pwquota> + +From F<i_pwd.U>: + +This variable conditionally defines C<PWQUOTA>, which indicates +that struct passwd contains pw_quota. + +=item C<d_qgcvt> + +From F<d_qgcvt.U>: + +This variable conditionally defines the C<HAS_QGCVT> symbol, which +indicates to the C program that the qgcvt() routine is available. + +=item C<d_quad> + +From F<quadtype.U>: + +This variable, if defined, tells that there's a 64-bit integer type, +quadtype. + +=item C<d_querylocale> + +From F<d_newlocale.U>: + +This variable conditionally defines the C<HAS_QUERYLOCALE> symbol, which +indicates to the C program that the querylocale() routine is available +to return the name of the locale for a category mask. + +=item C<d_random_r> + +From F<d_random_r.U>: + +This variable conditionally defines the C<HAS_RANDOM_R> symbol, +which indicates to the C program that the random_r() +routine is available. + +=item C<d_re_comp> + +From F<d_regcmp.U>: + +This variable conditionally defines the C<HAS_RECOMP> symbol, which +indicates to the C program that the re_comp() routine is available +for regular pattern matching (usually on C<BSD>). If so, it is likely that +re_exec() exists. + +=item C<d_readdir> + +From F<d_readdir.U>: + +This variable conditionally defines C<HAS_READDIR> if readdir() is +available to read directory entries. + +=item C<d_readdir64_r> + +From F<d_readdir64_r.U>: + +This variable conditionally defines the HAS_READDIR64_R symbol, +which indicates to the C program that the readdir64_r() +routine is available. + +=item C<d_readdir_r> + +From F<d_readdir_r.U>: + +This variable conditionally defines the C<HAS_READDIR_R> symbol, +which indicates to the C program that the readdir_r() +routine is available. + +=item C<d_readlink> + +From F<d_readlink.U>: + +This variable conditionally defines the C<HAS_READLINK> symbol, which +indicates to the C program that the readlink() routine is available +to read the value of a symbolic link. + +=item C<d_readv> + +From F<d_readv.U>: + +This variable conditionally defines the C<HAS_READV> symbol, which +indicates to the C program that the readv() routine is available. + +=item C<d_recvmsg> + +From F<d_recvmsg.U>: + +This variable conditionally defines the C<HAS_RECVMSG> symbol, which +indicates to the C program that the recvmsg() routine is available. + +=item C<d_regcmp> + +From F<d_regcmp.U>: + +This variable conditionally defines the C<HAS_REGCMP> symbol, which +indicates to the C program that the regcmp() routine is available +for regular pattern matching (usually on System V). + +=item C<d_regcomp> + +From F<d_regcmp.U>: + +This variable conditionally defines the C<HAS_REGCOMP> symbol, which +indicates to the C program that the regcomp() routine is available +for regular pattern matching (usually on F<POSIX.2> conforming systems). + +=item C<d_remainder> + +From F<d_remainder.U>: + +This variable conditionally defines the C<HAS_REMAINDER> symbol, which +indicates to the C program that the remainder() routine is available. + +=item C<d_remquo> + +From F<d_remquo.U>: + +This variable conditionally defines the C<HAS_REMQUO> symbol, which +indicates to the C program that the remquo() routine is available. + +=item C<d_rename> + +From F<d_rename.U>: + +This variable conditionally defines the C<HAS_RENAME> symbol, which +indicates to the C program that the rename() routine is available +to rename files. + +=item C<d_renameat> + +From F<d_fsat.U>: + +This variable conditionally defines the C<HAS_RENAMEAT> symbol, which +indicates the C<POSIX> renameat() function is available. + +=item C<d_rewinddir> + +From F<d_readdir.U>: + +This variable conditionally defines C<HAS_REWINDDIR> if rewinddir() is +available. + +=item C<d_rint> + +From F<d_rint.U>: + +This variable conditionally defines the C<HAS_RINT> symbol, which +indicates to the C program that the rint() routine is available. + +=item C<d_rmdir> + +From F<d_rmdir.U>: + +This variable conditionally defines C<HAS_RMDIR> if rmdir() is +available to remove directories. + +=item C<d_round> + +From F<d_round.U>: + +This variable conditionally defines the C<HAS_ROUND> symbol, which +indicates to the C program that the round() routine is available. + +=item C<d_sbrkproto> + +From F<d_sbrkproto.U>: + +This variable conditionally defines the C<HAS_SBRK_PROTO> symbol, +which indicates to the C program that the system provides +a prototype for the sbrk() function. Otherwise, it is +up to the program to supply one. + +=item C<d_scalbn> + +From F<d_scalbn.U>: + +This variable conditionally defines the C<HAS_SCALBN> symbol, which +indicates to the C program that the scalbn() routine is available. + +=item C<d_scalbnl> + +From F<d_scalbnl.U>: + +This variable conditionally defines the C<HAS_SCALBNL> symbol, which +indicates to the C program that the scalbnl() routine is available. +If ilogbl is also present we can emulate frexpl. + +=item C<d_sched_yield> + +From F<d_pthread_y.U>: + +This variable conditionally defines the C<HAS_SCHED_YIELD> +symbol if the sched_yield routine is available to yield +the execution of the current thread. + +=item C<d_scm_rights> + +From F<d_socket.U>: + +This variable conditionally defines the C<HAS_SCM_RIGHTS> symbol, +which indicates that the C<SCM_RIGHTS> is available. #ifdef is +not enough because it may be an enum, glibc has been known to do this. + +=item C<d_SCNfldbl> + +From F<longdblfio.U>: + +This variable conditionally defines the PERL_PRIfldbl symbol, which +indicates that stdio has a symbol to scan long doubles. + +=item C<d_seekdir> + +From F<d_readdir.U>: + +This variable conditionally defines C<HAS_SEEKDIR> if seekdir() is +available. + +=item C<d_select> + +From F<d_select.U>: + +This variable conditionally defines C<HAS_SELECT> if select() is +available to select active file descriptors. A <sys/time.h> +inclusion may be necessary for the timeout field. + +=item C<d_sem> + +From F<d_sem.U>: + +This variable conditionally defines the C<HAS_SEM> symbol, which +indicates that the entire sem*(2) library is present. + +=item C<d_semctl> + +From F<d_semctl.U>: + +This variable conditionally defines the C<HAS_SEMCTL> symbol, which +indicates to the C program that the semctl() routine is available. + +=item C<d_semctl_semid_ds> + +From F<d_union_semun.U>: + +This variable conditionally defines C<USE_SEMCTL_SEMID_DS>, which +indicates that struct semid_ds * is to be used for semctl C<IPC_STAT>. + +=item C<d_semctl_semun> + +From F<d_union_semun.U>: + +This variable conditionally defines C<USE_SEMCTL_SEMUN>, which +indicates that union semun is to be used for semctl C<IPC_STAT>. + +=item C<d_semget> + +From F<d_semget.U>: + +This variable conditionally defines the C<HAS_SEMGET> symbol, which +indicates to the C program that the semget() routine is available. + +=item C<d_semop> + +From F<d_semop.U>: + +This variable conditionally defines the C<HAS_SEMOP> symbol, which +indicates to the C program that the semop() routine is available. + +=item C<d_sendmsg> + +From F<d_sendmsg.U>: + +This variable conditionally defines the C<HAS_SENDMSG> symbol, which +indicates to the C program that the sendmsg() routine is available. + +=item C<d_setegid> + +From F<d_setegid.U>: + +This variable conditionally defines the C<HAS_SETEGID> symbol, which +indicates to the C program that the setegid() routine is available +to change the effective gid of the current program. + +=item C<d_seteuid> + +From F<d_seteuid.U>: + +This variable conditionally defines the C<HAS_SETEUID> symbol, which +indicates to the C program that the seteuid() routine is available +to change the effective uid of the current program. + +=item C<d_setgrent> + +From F<d_setgrent.U>: + +This variable conditionally defines the C<HAS_SETGRENT> symbol, which +indicates to the C program that the setgrent() routine is available +for initializing sequential access to the group database. + +=item C<d_setgrent_r> + +From F<d_setgrent_r.U>: + +This variable conditionally defines the C<HAS_SETGRENT_R> symbol, +which indicates to the C program that the setgrent_r() +routine is available. + +=item C<d_setgrps> + +From F<d_setgrps.U>: + +This variable conditionally defines the C<HAS_SETGROUPS> symbol, which +indicates to the C program that the setgroups() routine is available +to set the list of process groups. + +=item C<d_sethent> + +From F<d_sethent.U>: + +This variable conditionally defines C<HAS_SETHOSTENT> if sethostent() is +available. + +=item C<d_sethostent_r> + +From F<d_sethostent_r.U>: + +This variable conditionally defines the C<HAS_SETHOSTENT_R> symbol, +which indicates to the C program that the sethostent_r() +routine is available. + +=item C<d_setitimer> + +From F<d_setitimer.U>: + +This variable conditionally defines the C<HAS_SETITIMER> symbol, which +indicates to the C program that the setitimer() routine is available. + +=item C<d_setlinebuf> + +From F<d_setlnbuf.U>: + +This variable conditionally defines the C<HAS_SETLINEBUF> symbol, which +indicates to the C program that the setlinebuf() routine is available +to change stderr or stdout from block-buffered or unbuffered to a +line-buffered mode. + +=item C<d_setlocale> + +From F<d_setlocale.U>: + +This variable conditionally defines C<HAS_SETLOCALE> if setlocale() is +available to handle locale-specific ctype implementations. + +=item C<d_setlocale_accepts_any_locale_name> + +From F<d_setlocale.U>: + +This variable conditionally defines C<SETLOCALE_ACCEPTS_ANY_LOCALE_NAME> +if setlocale() accepts any locale name. + +=item C<d_setlocale_r> + +From F<d_setlocale_r.U>: + +This variable conditionally defines the C<HAS_SETLOCALE_R> symbol, +which indicates to the C program that the setlocale_r() +routine is available. + +=item C<d_setnent> + +From F<d_setnent.U>: + +This variable conditionally defines C<HAS_SETNETENT> if setnetent() is +available. + +=item C<d_setnetent_r> + +From F<d_setnetent_r.U>: + +This variable conditionally defines the C<HAS_SETNETENT_R> symbol, +which indicates to the C program that the setnetent_r() +routine is available. + +=item C<d_setpent> + +From F<d_setpent.U>: + +This variable conditionally defines C<HAS_SETPROTOENT> if setprotoent() is +available. + +=item C<d_setpgid> + +From F<d_setpgid.U>: + +This variable conditionally defines the C<HAS_SETPGID> symbol if the +setpgid(pid, gpid) function is available to set process group C<ID>. + +=item C<d_setpgrp> + +From F<d_setpgrp.U>: + +This variable conditionally defines C<HAS_SETPGRP> if setpgrp() is +available to set the current process group. + +=item C<d_setpgrp2> + +From F<d_setpgrp2.U>: + +This variable conditionally defines the HAS_SETPGRP2 symbol, which +indicates to the C program that the setpgrp2() (as in F<DG/C<UX>>) routine +is available to set the current process group. + +=item C<d_setprior> + +From F<d_setprior.U>: + +This variable conditionally defines C<HAS_SETPRIORITY> if setpriority() +is available to set a process's priority. + +=item C<d_setproctitle> + +From F<d_setproctitle.U>: + +This variable conditionally defines the C<HAS_SETPROCTITLE> symbol, +which indicates to the C program that the setproctitle() routine +is available. + +=item C<d_setprotoent_r> + +From F<d_setprotoent_r.U>: + +This variable conditionally defines the C<HAS_SETPROTOENT_R> symbol, +which indicates to the C program that the setprotoent_r() +routine is available. + +=item C<d_setpwent> + +From F<d_setpwent.U>: + +This variable conditionally defines the C<HAS_SETPWENT> symbol, which +indicates to the C program that the setpwent() routine is available +for initializing sequential access to the passwd database. + +=item C<d_setpwent_r> + +From F<d_setpwent_r.U>: + +This variable conditionally defines the C<HAS_SETPWENT_R> symbol, +which indicates to the C program that the setpwent_r() +routine is available. + +=item C<d_setregid> + +From F<d_setregid.U>: + +This variable conditionally defines C<HAS_SETREGID> if setregid() is +available to change the real and effective gid of the current +process. + +=item C<d_setresgid> + +From F<d_setregid.U>: + +This variable conditionally defines C<HAS_SETRESGID> if setresgid() is +available to change the real, effective and saved gid of the current +process. + +=item C<d_setresuid> + +From F<d_setreuid.U>: + +This variable conditionally defines C<HAS_SETREUID> if setresuid() is +available to change the real, effective and saved uid of the current +process. + +=item C<d_setreuid> + +From F<d_setreuid.U>: + +This variable conditionally defines C<HAS_SETREUID> if setreuid() is +available to change the real and effective uid of the current +process. + +=item C<d_setrgid> + +From F<d_setrgid.U>: + +This variable conditionally defines the C<HAS_SETRGID> symbol, which +indicates to the C program that the setrgid() routine is available +to change the real gid of the current program. + +=item C<d_setruid> + +From F<d_setruid.U>: + +This variable conditionally defines the C<HAS_SETRUID> symbol, which +indicates to the C program that the setruid() routine is available +to change the real uid of the current program. + +=item C<d_setsent> + +From F<d_setsent.U>: + +This variable conditionally defines C<HAS_SETSERVENT> if setservent() is +available. + +=item C<d_setservent_r> + +From F<d_setservent_r.U>: + +This variable conditionally defines the C<HAS_SETSERVENT_R> symbol, +which indicates to the C program that the setservent_r() +routine is available. + +=item C<d_setsid> + +From F<d_setsid.U>: + +This variable conditionally defines C<HAS_SETSID> if setsid() is +available to set the process group C<ID>. + +=item C<d_setvbuf> + +From F<d_setvbuf.U>: + +This variable conditionally defines the C<HAS_SETVBUF> symbol, which +indicates to the C program that the setvbuf() routine is available +to change buffering on an open stdio stream. + +=item C<d_shm> + +From F<d_shm.U>: + +This variable conditionally defines the C<HAS_SHM> symbol, which +indicates that the entire shm*(2) library is present. + +=item C<d_shmat> + +From F<d_shmat.U>: + +This variable conditionally defines the C<HAS_SHMAT> symbol, which +indicates to the C program that the shmat() routine is available. + +=item C<d_shmatprototype> + +From F<d_shmat.U>: + +This variable conditionally defines the C<HAS_SHMAT_PROTOTYPE> +symbol, which indicates that F<sys/shm.h> has a prototype for +shmat. + +=item C<d_shmctl> + +From F<d_shmctl.U>: + +This variable conditionally defines the C<HAS_SHMCTL> symbol, which +indicates to the C program that the shmctl() routine is available. + +=item C<d_shmdt> + +From F<d_shmdt.U>: + +This variable conditionally defines the C<HAS_SHMDT> symbol, which +indicates to the C program that the shmdt() routine is available. + +=item C<d_shmget> + +From F<d_shmget.U>: + +This variable conditionally defines the C<HAS_SHMGET> symbol, which +indicates to the C program that the shmget() routine is available. + +=item C<d_sigaction> + +From F<d_sigaction.U>: + +This variable conditionally defines the C<HAS_SIGACTION> symbol, which +indicates that the Vr4 sigaction() routine is available. + +=item C<d_siginfo_si_addr> + +From F<d_siginfo_si.U>: + +This variable conditionally defines the C<HAS_SIGINFO_SI_ADDR> symbol, +which indicates that the siginfo_t struct has the si_addr member. + +=item C<d_siginfo_si_band> + +From F<d_siginfo_si.U>: + +This variable conditionally defines the C<HAS_SIGINFO_SI_BAND> symbol, +which indicates that the siginfo_t struct has the si_band member. + +=item C<d_siginfo_si_errno> + +From F<d_siginfo_si.U>: + +This variable conditionally defines the C<HAS_SIGINFO_SI_ERRNO> symbol, +which indicates that the siginfo_t struct has the si_errno member. + +=item C<d_siginfo_si_fd> + +From F<d_siginfo_si.U>: + +This variable conditionally defines the C<HAS_SIGINFO_SI_FD> symbol, +which indicates that the siginfo_t struct has the si_fd member. + +=item C<d_siginfo_si_pid> + +From F<d_siginfo_si.U>: + +This variable conditionally defines the C<HAS_SIGINFO_SI_PID> symbol, +which indicates that the siginfo_t struct has the si_pid member. + +=item C<d_siginfo_si_status> + +From F<d_siginfo_si.U>: + +This variable conditionally defines the C<HAS_SIGINFO_SI_STATUS> symbol, +which indicates that the siginfo_t struct has the si_status member. + +=item C<d_siginfo_si_uid> + +From F<d_siginfo_si.U>: + +This variable conditionally defines the C<HAS_SIGINFO_SI_UID> symbol, +which indicates that the siginfo_t struct has the si_uid member. + +=item C<d_siginfo_si_value> + +From F<d_siginfo_si.U>: + +This variable conditionally defines the C<HAS_SIGINFO_SI_VALUE> symbol, +which indicates that the siginfo_t struct has the si_value member. + +=item C<d_signbit> + +From F<d_signbit.U>: + +This variable conditionally defines the C<HAS_SIGNBIT> symbol, which +indicates to the C program that the signbit() routine is available +and safe to use with perl's intern C<NV> type. + +=item C<d_sigprocmask> + +From F<d_sigprocmask.U>: + +This variable conditionally defines C<HAS_SIGPROCMASK> +if sigprocmask() is available to examine or change the signal mask +of the calling process. + +=item C<d_sigsetjmp> + +From F<d_sigsetjmp.U>: + +This variable conditionally defines the C<HAS_SIGSETJMP> symbol, +which indicates that the sigsetjmp() routine is available to +call setjmp() and optionally save the process's signal mask. + +=item C<d_sin6_scope_id> + +From F<d_socket.U>: + +This variable conditionally defines the HAS_SIN6_SCOPE_ID symbol, which +indicates that a struct sockaddr_in6 structure has the sin6_scope_id +member. + +=item C<d_sitearch> + +From F<sitearch.U>: + +This variable conditionally defines C<SITEARCH> to hold the pathname +of architecture-dependent library files for $package. If +$sitearch is the same as $archlib, then this is set to undef. + +=item C<d_snprintf> + +From F<d_snprintf.U>: + +This variable conditionally defines the C<HAS_SNPRINTF> symbol, which +indicates to the C program that the snprintf () library function +is available. + +=item C<d_sockaddr_in6> + +From F<d_socket.U>: + +This variable conditionally defines the HAS_SOCKADDR_IN6 symbol, which +indicates the availability of a struct sockaddr_in6. + +=item C<d_sockaddr_sa_len> + +From F<d_socket.U>: + +This variable conditionally defines the C<HAS_SOCKADDR_SA_LEN> symbol, +which indicates that a struct sockaddr structure has the sa_len +member. + +=item C<d_sockaddr_storage> + +From F<d_socket.U>: + +This variable conditionally defines the C<HAS_SOCKADDR_STORAGE> symbol, +which indicates the availability of a struct sockaddr_storage. + +=item C<d_sockatmark> + +From F<d_sockatmark.U>: + +This variable conditionally defines the C<HAS_SOCKATMARK> symbol, which +indicates to the C program that the sockatmark() routine is available. + +=item C<d_sockatmarkproto> + +From F<d_sockatmarkproto.U>: + +This variable conditionally defines the C<HAS_SOCKATMARK_PROTO> symbol, +which indicates to the C program that the system provides +a prototype for the sockatmark() function. Otherwise, it is +up to the program to supply one. + +=item C<d_socket> + +From F<d_socket.U>: + +This variable conditionally defines C<HAS_SOCKET>, which indicates +that the C<BSD> socket interface is supported. + +=item C<d_socklen_t> + +From F<d_socklen_t.U>: + +This symbol will be defined if the C compiler supports socklen_t. + +=item C<d_sockpair> + +From F<d_socket.U>: + +This variable conditionally defines the C<HAS_SOCKETPAIR> symbol, which +indicates that the C<BSD> socketpair() is supported. + +=item C<d_socks5_init> + +From F<d_socks5_init.U>: + +This variable conditionally defines the HAS_SOCKS5_INIT symbol, which +indicates to the C program that the socks5_init() routine is available. + +=item C<d_sqrtl> + +From F<d_sqrtl.U>: + +This variable conditionally defines the C<HAS_SQRTL> symbol, which +indicates to the C program that the sqrtl() routine is available. + +=item C<d_srand48_r> + +From F<d_srand48_r.U>: + +This variable conditionally defines the HAS_SRAND48_R symbol, +which indicates to the C program that the srand48_r() +routine is available. + +=item C<d_srandom_r> + +From F<d_srandom_r.U>: + +This variable conditionally defines the C<HAS_SRANDOM_R> symbol, +which indicates to the C program that the srandom_r() +routine is available. + +=item C<d_sresgproto> + +From F<d_sresgproto.U>: + +This variable conditionally defines the C<HAS_SETRESGID_PROTO> symbol, +which indicates to the C program that the system provides +a prototype for the setresgid() function. Otherwise, it is +up to the program to supply one. + +=item C<d_sresuproto> + +From F<d_sresuproto.U>: + +This variable conditionally defines the C<HAS_SETRESUID_PROTO> symbol, +which indicates to the C program that the system provides +a prototype for the setresuid() function. Otherwise, it is +up to the program to supply one. + +=item C<d_stat> + +From F<d_stat.U>: + +This variable conditionally defines C<HAS_STAT> if stat() is +available to get file status. + +=item C<d_statblks> + +From F<d_statblks.U>: + +This variable conditionally defines C<USE_STAT_BLOCKS> +if this system has a stat structure declaring +st_blksize and st_blocks. + +=item C<d_statfs_f_flags> + +From F<d_statfs_f_flags.U>: + +This variable conditionally defines the C<HAS_STRUCT_STATFS_F_FLAGS> +symbol, which indicates to struct statfs from has f_flags member. +This kind of struct statfs is coming from F<sys/mount.h> (C<BSD>), +not from F<sys/statfs.h> (C<SYSV>). + +=item C<d_statfs_s> + +From F<d_statfs_s.U>: + +This variable conditionally defines the C<HAS_STRUCT_STATFS> symbol, +which indicates that the struct statfs is supported. + +=item C<d_static_inline> + +From F<d_static_inline.U>: + +This variable conditionally defines the C<HAS_STATIC_INLINE> symbol, +which indicates that the C compiler supports C99-style static +inline. That is, the function can't be called from another +translation unit. + +=item C<d_statvfs> + +From F<d_statvfs.U>: + +This variable conditionally defines the C<HAS_STATVFS> symbol, which +indicates to the C program that the statvfs() routine is available. + +=item C<d_stdio_cnt_lval> + +From F<d_stdstdio.U>: + +This variable conditionally defines C<STDIO_CNT_LVALUE> if the +C<FILE_cnt> macro can be used as an lvalue. + +=item C<d_stdio_ptr_lval> + +From F<d_stdstdio.U>: + +This variable conditionally defines C<STDIO_PTR_LVALUE> if the +C<FILE_ptr> macro can be used as an lvalue. + +=item C<d_stdio_ptr_lval_nochange_cnt> + +From F<d_stdstdio.U>: + +This symbol is defined if using the C<FILE_ptr> macro as an lvalue +to increase the pointer by n leaves File_cnt(fp) unchanged. + +=item C<d_stdio_ptr_lval_sets_cnt> + +From F<d_stdstdio.U>: + +This symbol is defined if using the C<FILE_ptr> macro as an lvalue +to increase the pointer by n has the side effect of decreasing the +value of File_cnt(fp) by n. + +=item C<d_stdio_stream_array> + +From F<stdio_streams.U>: + +This variable tells whether there is an array holding +the stdio streams. + +=item C<d_stdiobase> + +From F<d_stdstdio.U>: + +This variable conditionally defines C<USE_STDIO_BASE> if this system +has a C<FILE> structure declaring a usable _base field (or equivalent) +in F<stdio.h>. + +=item C<d_stdstdio> + +From F<d_stdstdio.U>: + +This variable conditionally defines C<USE_STDIO_PTR> if this system +has a C<FILE> structure declaring usable _ptr and _cnt fields (or +equivalent) in F<stdio.h>. + +=item C<d_strcoll> + +From F<d_strcoll.U>: + +This variable conditionally defines C<HAS_STRCOLL> if strcoll() is +available to compare strings using collating information. + +=item C<d_strerror_l> + +From F<d_strerror_l.U>: + +This variable conditionally defines the C<HAS_STRERROR_L> symbol, which +indicates to the C program that the strerror_l() routine is available +to return the error message for a given errno value in a particular +locale (identified by a locale_t object). + +=item C<d_strerror_r> + +From F<d_strerror_r.U>: + +This variable conditionally defines the C<HAS_STRERROR_R> symbol, +which indicates to the C program that the strerror_r() +routine is available. + +=item C<d_strftime> + +From F<d_strftime.U>: + +This variable conditionally defines the C<HAS_STRFTIME> symbol, which +indicates to the C program that the strftime() routine is available. + +=item C<d_strlcat> + +From F<d_strlcat.U>: + +This variable conditionally defines the C<HAS_STRLCAT> symbol, which +indicates to the C program that the strlcat () routine is available. + +=item C<d_strlcpy> + +From F<d_strlcpy.U>: + +This variable conditionally defines the C<HAS_STRLCPY> symbol, which +indicates to the C program that the strlcpy () routine is available. + +=item C<d_strnlen> + +From F<d_strnlen.U>: + +This variable conditionally defines the C<HAS_STRNLEN> symbol, which +indicates to the C program that the strnlen () routine is available. + +=item C<d_strtod> + +From F<d_strtod.U>: + +This variable conditionally defines the C<HAS_STRTOD> symbol, which +indicates to the C program that the strtod() routine is available +to provide better numeric string conversion than atof(). + +=item C<d_strtod_l> + +From F<d_strtod_l.U>: + +This variable conditionally defines the C<HAS_STRTOD_L> symbol, which +indicates to the C program that the strtod_l() routine is available. + +=item C<d_strtol> + +From F<d_strtol.U>: + +This variable conditionally defines the C<HAS_STRTOL> symbol, which +indicates to the C program that the strtol() routine is available +to provide better numeric string conversion than atoi() and friends. + +=item C<d_strtold> + +From F<d_strtold.U>: + +This variable conditionally defines the C<HAS_STRTOLD> symbol, which +indicates to the C program that the strtold() routine is available. + +=item C<d_strtold_l> + +From F<d_strtold_l.U>: + +This variable conditionally defines the C<HAS_STRTOLD_L> symbol, which +indicates to the C program that the strtold_l() routine is available. + +=item C<d_strtoll> + +From F<d_strtoll.U>: + +This variable conditionally defines the C<HAS_STRTOLL> symbol, which +indicates to the C program that the strtoll() routine is available. + +=item C<d_strtoq> + +From F<d_strtoq.U>: + +This variable conditionally defines the C<HAS_STRTOQ> symbol, which +indicates to the C program that the strtoq() routine is available. + +=item C<d_strtoul> + +From F<d_strtoul.U>: + +This variable conditionally defines the C<HAS_STRTOUL> symbol, which +indicates to the C program that the strtoul() routine is available +to provide conversion of strings to unsigned long. + +=item C<d_strtoull> + +From F<d_strtoull.U>: + +This variable conditionally defines the C<HAS_STRTOULL> symbol, which +indicates to the C program that the strtoull() routine is available. + +=item C<d_strtouq> + +From F<d_strtouq.U>: + +This variable conditionally defines the C<HAS_STRTOUQ> symbol, which +indicates to the C program that the strtouq() routine is available. + +=item C<d_strxfrm> + +From F<d_strxfrm.U>: + +This variable conditionally defines C<HAS_STRXFRM> if strxfrm() is +available to transform strings. + +=item C<d_suidsafe> + +From F<d_dosuid.U>: + +This variable conditionally defines C<SETUID_SCRIPTS_ARE_SECURE_NOW> +if setuid scripts can be secure. This test looks in F</dev/fd/>. + +=item C<d_symlink> + +From F<d_symlink.U>: + +This variable conditionally defines the C<HAS_SYMLINK> symbol, which +indicates to the C program that the symlink() routine is available +to create symbolic links. + +=item C<d_syscall> + +From F<d_syscall.U>: + +This variable conditionally defines C<HAS_SYSCALL> if syscall() is +available call arbitrary system calls. + +=item C<d_syscallproto> + +From F<d_syscallproto.U>: + +This variable conditionally defines the C<HAS_SYSCALL_PROTO> symbol, +which indicates to the C program that the system provides +a prototype for the syscall() function. Otherwise, it is +up to the program to supply one. + +=item C<d_sysconf> + +From F<d_sysconf.U>: + +This variable conditionally defines the C<HAS_SYSCONF> symbol, which +indicates to the C program that the sysconf() routine is available +to determine system related limits and options. + +=item C<d_sysernlst> + +From F<d_strerror.U>: + +This variable conditionally defines C<HAS_SYS_ERRNOLIST> if sys_errnolist[] +is available to translate error numbers to the symbolic name. + +=item C<d_syserrlst> + +From F<d_strerror.U>: + +This variable conditionally defines C<HAS_SYS_ERRLIST> if sys_errlist[] is +available to translate error numbers to strings. + +=item C<d_system> + +From F<d_system.U>: + +This variable conditionally defines C<HAS_SYSTEM> if system() is +available to issue a shell command. + +=item C<d_tcgetpgrp> + +From F<d_tcgtpgrp.U>: + +This variable conditionally defines the C<HAS_TCGETPGRP> symbol, which +indicates to the C program that the tcgetpgrp() routine is available. +to get foreground process group C<ID>. + +=item C<d_tcsetpgrp> + +From F<d_tcstpgrp.U>: + +This variable conditionally defines the C<HAS_TCSETPGRP> symbol, which +indicates to the C program that the tcsetpgrp() routine is available +to set foreground process group C<ID>. + +=item C<d_telldir> + +From F<d_readdir.U>: + +This variable conditionally defines C<HAS_TELLDIR> if telldir() is +available. + +=item C<d_telldirproto> + +From F<d_telldirproto.U>: + +This variable conditionally defines the C<HAS_TELLDIR_PROTO> symbol, +which indicates to the C program that the system provides +a prototype for the telldir() function. Otherwise, it is +up to the program to supply one. + +=item C<d_tgamma> + +From F<d_tgamma.U>: + +This variable conditionally defines the C<HAS_TGAMMA> symbol, which +indicates to the C program that the tgamma() routine is available +for the gamma function. See also d_lgamma. + +=item C<d_thread_safe_nl_langinfo_l> + +From F<d_nl_langinfo_l.U>: + +This variable contains the eventual value of the +C<HAS_THREAD_SAFE_NL_LANGINFO_L> symbol, which indicates if the +nl_langinfo_l() function exists and is thread-safe. + +=item C<d_time> + +From F<d_time.U>: + +This variable conditionally defines the C<HAS_TIME> symbol, which indicates +that the time() routine exists. The time() routine is normally +provided on C<UNIX> systems. + +=item C<d_timegm> + +From F<d_timegm.U>: + +This variable conditionally defines the C<HAS_TIMEGM> symbol, which +indicates to the C program that the timegm () routine is available. + +=item C<d_times> + +From F<d_times.U>: + +This variable conditionally defines the C<HAS_TIMES> symbol, which indicates +that the times() routine exists. The times() routine is normally +provided on C<UNIX> systems. You may have to include <sys/times.h>. + +=item C<d_tm_tm_gmtoff> + +From F<i_time.U>: + +This variable conditionally defines C<HAS_TM_TM_GMTOFF>, which indicates +to the C program that the struct tm has the tm_gmtoff field. + +=item C<d_tm_tm_zone> + +From F<i_time.U>: + +This variable conditionally defines C<HAS_TM_TM_ZONE>, which indicates +to the C program that the struct tm has the tm_zone field. + +=item C<d_tmpnam_r> + +From F<d_tmpnam_r.U>: + +This variable conditionally defines the C<HAS_TMPNAM_R> symbol, +which indicates to the C program that the tmpnam_r() +routine is available. + +=item C<d_towlower> + +From F<d_towlower.U>: + +This variable conditionally defines the C<HAS_TOWLOWER> symbol, which +indicates to the C program that the towlower() routine is available. + +=item C<d_towupper> + +From F<d_towupper.U>: + +This variable conditionally defines the C<HAS_TOWUPPER> symbol, which +indicates to the C program that the towupper() routine is available. + +=item C<d_trunc> + +From F<d_trunc.U>: + +This variable conditionally defines the C<HAS_TRUNC> symbol, which +indicates to the C program that the trunc() routine is available +to round doubles towards zero. + +=item C<d_truncate> + +From F<d_truncate.U>: + +This variable conditionally defines C<HAS_TRUNCATE> if truncate() is +available to truncate files. + +=item C<d_truncl> + +From F<d_truncl.U>: + +This variable conditionally defines the C<HAS_TRUNCL> symbol, which +indicates to the C program that the truncl() routine is available +to round long doubles towards zero. If copysignl is also present, +we can emulate modfl. + +=item C<d_ttyname_r> + +From F<d_ttyname_r.U>: + +This variable conditionally defines the C<HAS_TTYNAME_R> symbol, +which indicates to the C program that the ttyname_r() +routine is available. + +=item C<d_tzname> + +From F<d_tzname.U>: + +This variable conditionally defines C<HAS_TZNAME> if tzname[] is +available to access timezone names. + +=item C<d_u32align> + +From F<d_u32align.U>: + +This variable tells whether you must access character data +through U32-aligned pointers. + +=item C<d_ualarm> + +From F<d_ualarm.U>: + +This variable conditionally defines the C<HAS_UALARM> symbol, which +indicates to the C program that the ualarm() routine is available. + +=item C<d_umask> + +From F<d_umask.U>: + +This variable conditionally defines the C<HAS_UMASK> symbol, which +indicates to the C program that the umask() routine is available. +to set and get the value of the file creation mask. + +=item C<d_uname> + +From F<d_gethname.U>: + +This variable conditionally defines the C<HAS_UNAME> symbol, which +indicates to the C program that the uname() routine may be +used to derive the host name. + +=item C<d_union_semun> + +From F<d_union_semun.U>: + +This variable conditionally defines C<HAS_UNION_SEMUN> if the +union semun is defined by including <sys/sem.h>. + +=item C<d_unlinkat> + +From F<d_fsat.U>: + +This variable conditionally defines the C<HAS_UNLINKAT> symbol, which +indicates the C<POSIX> unlinkat() function isavailable. + +=item C<d_unordered> + +From F<d_unordered.U>: + +This variable conditionally defines the C<HAS_UNORDERED> symbol, which +indicates to the C program that the unordered() routine is available. + +=item C<d_unsetenv> + +From F<d_unsetenv.U>: + +This variable conditionally defines the C<HAS_UNSETENV> symbol, which +indicates to the C program that the unsetenv () routine is available. + +=item C<d_uselocale> + +From F<d_newlocale.U>: + +This variable conditionally defines the C<HAS_USELOCALE> symbol, which +indicates to the C program that the uselocale() routine is available +to set the current locale for the calling thread. + +=item C<d_usleep> + +From F<d_usleep.U>: + +This variable conditionally defines C<HAS_USLEEP> if usleep() is +available to do high granularity sleeps. + +=item C<d_usleepproto> + +From F<d_usleepproto.U>: + +This variable conditionally defines the C<HAS_USLEEP_PROTO> symbol, +which indicates to the C program that the system provides +a prototype for the usleep() function. Otherwise, it is +up to the program to supply one. + +=item C<d_ustat> + +From F<d_ustat.U>: + +This variable conditionally defines C<HAS_USTAT> if ustat() is +available to query file system statistics by dev_t. + +=item C<d_vendorarch> + +From F<vendorarch.U>: + +This variable conditionally defined C<PERL_VENDORARCH>. + +=item C<d_vendorbin> + +From F<vendorbin.U>: + +This variable conditionally defines C<PERL_VENDORBIN>. + +=item C<d_vendorlib> + +From F<vendorlib.U>: + +This variable conditionally defines C<PERL_VENDORLIB>. + +=item C<d_vendorscript> + +From F<vendorscript.U>: + +This variable conditionally defines C<PERL_VENDORSCRIPT>. + +=item C<d_vfork> + +From F<d_vfork.U>: + +This variable conditionally defines the C<HAS_VFORK> symbol, which +indicates the vfork() routine is available. + +=item C<d_void_closedir> + +From F<d_closedir.U>: + +This variable conditionally defines C<VOID_CLOSEDIR> if closedir() +does not return a value. + +=item C<d_voidsig> + +From F<d_voidsig.U>: + +This variable conditionally defines C<VOIDSIG> if this system +declares "void (*signal(...))()" in F<signal.h>. The old way was to +declare it as "int (*signal(...))()". + +=item C<d_voidtty> + +From F<i_sysioctl.U>: + +This variable conditionally defines C<USE_IOCNOTTY> to indicate that the +ioctl() call with C<TIOCNOTTY> should be used to void tty association. +Otherwise (on C<USG> probably), it is enough to close the standard file +descriptors and do a setpgrp(). + +=item C<d_vsnprintf> + +From F<d_snprintf.U>: + +This variable conditionally defines the C<HAS_VSNPRINTF> symbol, which +indicates to the C program that the vsnprintf () library function +is available. + +=item C<d_wait4> + +From F<d_wait4.U>: + +This variable conditionally defines the HAS_WAIT4 symbol, which +indicates the wait4() routine is available. + +=item C<d_waitpid> + +From F<d_waitpid.U>: + +This variable conditionally defines C<HAS_WAITPID> if waitpid() is +available to wait for child process. + +=item C<d_wcrtomb> + +From F<d_wcrtomb.U>: + +This variable conditionally defines the C<HAS_WCRTOMB> symbol if the +wcrtomb() routine is available to be used to convert a wide character +into a multi-byte character. + +=item C<d_wcscmp> + +From F<d_wcscmp.U>: + +This variable conditionally defines the C<HAS_WCSCMP> symbol if the +wcscmp() routine is available and can be used to compare wide +character strings. + +=item C<d_wcstombs> + +From F<d_wcstombs.U>: + +This variable conditionally defines the C<HAS_WCSTOMBS> symbol, which +indicates to the C program that the wcstombs() routine is available +to convert wide character strings to multibyte strings. + +=item C<d_wcsxfrm> + +From F<d_wcsxfrm.U>: + +This variable conditionally defines the C<HAS_WCSXFRM> symbol if the +wcsxfrm() routine is available and can be used to compare wide +character strings. + +=item C<d_wctomb> + +From F<d_wctomb.U>: + +This variable conditionally defines the C<HAS_WCTOMB> symbol, which +indicates to the C program that the wctomb() routine is available +to convert a wide character to a multibyte. + +=item C<d_writev> + +From F<d_writev.U>: + +This variable conditionally defines the C<HAS_WRITEV> symbol, which +indicates to the C program that the writev() routine is available. + +=item C<d_xenix> + +From F<Guess.U>: + +This variable conditionally defines the symbol C<XENIX>, which alerts +the C program that it runs under Xenix. + +=item C<date> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the date program. After Configure runs, +the value is reset to a plain C<date> and is not useful. + +=item C<db_hashtype> + +From F<i_db.U>: + +This variable contains the type of the hash structure element +in the <db.h> header file. In older versions of C<DB>, it was +int, while in newer ones it is u_int32_t. + +=item C<db_prefixtype> + +From F<i_db.U>: + +This variable contains the type of the prefix structure element +in the <db.h> header file. In older versions of C<DB>, it was +int, while in newer ones it is size_t. + +=item C<db_version_major> + +From F<i_db.U>: + +This variable contains the major version number of +Berkeley C<DB> found in the <db.h> header file. + +=item C<db_version_minor> + +From F<i_db.U>: + +This variable contains the minor version number of +Berkeley C<DB> found in the <db.h> header file. +For C<DB> version 1 this is always 0. + +=item C<db_version_patch> + +From F<i_db.U>: + +This variable contains the patch version number of +Berkeley C<DB> found in the <db.h> header file. +For C<DB> version 1 this is always 0. + +=item C<default_inc_excludes_dot> + +From F<defaultincdot.U>: + +When defined, remove the legacy F<.> from @C<INC> + +=item C<direntrytype> + +From F<i_dirent.U>: + +This symbol is set to C<struct direct> or C<struct dirent> depending on +whether dirent is available or not. You should use this pseudo type to +portably declare your directory entries. + +=item C<dlext> + +From F<dlext.U>: + +This variable contains the extension that is to be used for the +dynamically loaded modules that perl generates. + +=item C<dlsrc> + +From F<dlsrc.U>: + +This variable contains the name of the dynamic loading file that +will be used with the package. + +=item C<doubleinfbytes> + +From F<infnan.U>: + +This variable contains comma-separated list of hexadecimal bytes +for the double precision infinity. + +=item C<doublekind> + +From F<longdblfio.U>: + +This variable, if defined, encodes the type of a double: +1 = C<IEEE> 754 32-bit little endian, +2 = C<IEEE> 754 32-bit big endian, +3 = C<IEEE> 754 64-bit little endian, +4 = C<IEEE> 754 64-bit big endian, +5 = C<IEEE> 754 128-bit little endian, +6 = C<IEEE> 754 128-bit big endian, +7 = C<IEEE> 754 64-bit mixed endian le-be, +8 = C<IEEE> 754 64-bit mixed endian be-le, +9 = C<VAX> 32bit little endian F float format +10 = C<VAX> 64bit little endian D float format +11 = C<VAX> 64bit little endian G float format +12 = C<IBM> 32bit format +13 = C<IBM> 64bit format +14 = Cray 64bit format +-1 = unknown format. + +=item C<doublemantbits> + +From F<mantbits.U>: + +This symbol, if defined, tells how many mantissa bits +there are in double precision floating point format. +Note that this is usually C<DBL_MANT_DIG> minus one, since +with the standard C<IEEE> 754 formats C<DBL_MANT_DIG> includes +the implicit bit which doesn't really exist. + +=item C<doublenanbytes> + +From F<infnan.U>: + +This variable contains comma-separated list of hexadecimal bytes +for the double precision not-a-number. + +=item C<doublesize> + +From F<doublesize.U>: + +This variable contains the value of the C<DOUBLESIZE> symbol, which +indicates to the C program how many bytes there are in a double. + +=item C<drand01> + +From F<randfunc.U>: + +Indicates the macro to be used to generate normalized +random numbers. Uses randfunc, often divided by +(double) (((unsigned long) 1 << randbits)) in order to +normalize the result. +In C programs, the macro C<Drand01> is mapped to drand01. + +=item C<drand48_r_proto> + +From F<d_drand48_r.U>: + +This variable encodes the prototype of drand48_r. +It is zero if d_drand48_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_drand48_r +is defined. + +=item C<dtrace> + +From F<usedtrace.U>: + +This variable holds the location of the dtrace executable. + +=item C<dtraceobject> + +From F<dtraceobject.U>: + +Whether we need to build an object file with the dtrace tool. + +=item C<dtracexnolibs> + +From F<dtraceobject.U>: + +Whether dtrace accepts -xnolibs. If available we call dtrace -h +and dtrace -G with -xnolibs to allow dtrace to run in a jail on +FreeBSD. + +=item C<dynamic_ext> + +From F<Extensions.U>: + +This variable holds a list of C<XS> extension files we want to +link dynamically into the package. It is used by Makefile. + +=back + +=head2 e + +=over 4 + +=item C<eagain> + +From F<nblock_io.U>: + +This variable bears the symbolic errno code set by read() when no +data is present on the file and non-blocking I/O was enabled (otherwise, +read() blocks naturally). + +=item C<ebcdic> + +From F<ebcdic.U>: + +This variable conditionally defines C<EBCDIC> if this +system uses C<EBCDIC> encoding. + +=item C<echo> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the echo program. After Configure runs, +the value is reset to a plain C<echo> and is not useful. + +=item C<egrep> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the egrep program. After Configure runs, +the value is reset to a plain C<egrep> and is not useful. + +=item C<emacs> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<endgrent_r_proto> + +From F<d_endgrent_r.U>: + +This variable encodes the prototype of endgrent_r. +It is zero if d_endgrent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endgrent_r +is defined. + +=item C<endhostent_r_proto> + +From F<d_endhostent_r.U>: + +This variable encodes the prototype of endhostent_r. +It is zero if d_endhostent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endhostent_r +is defined. + +=item C<endnetent_r_proto> + +From F<d_endnetent_r.U>: + +This variable encodes the prototype of endnetent_r. +It is zero if d_endnetent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endnetent_r +is defined. + +=item C<endprotoent_r_proto> + +From F<d_endprotoent_r.U>: + +This variable encodes the prototype of endprotoent_r. +It is zero if d_endprotoent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endprotoent_r +is defined. + +=item C<endpwent_r_proto> + +From F<d_endpwent_r.U>: + +This variable encodes the prototype of endpwent_r. +It is zero if d_endpwent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endpwent_r +is defined. + +=item C<endservent_r_proto> + +From F<d_endservent_r.U>: + +This variable encodes the prototype of endservent_r. +It is zero if d_endservent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_endservent_r +is defined. + +=item C<eunicefix> + +From F<Init.U>: + +When running under Eunice this variable contains a command which will +convert a shell script to the proper form of text file for it to be +executable by the shell. On other systems it is a no-op. + +=item C<exe_ext> + +From F<Unix.U>: + +This is an old synonym for _exe. + +=item C<expr> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the expr program. After Configure runs, +the value is reset to a plain C<expr> and is not useful. + +=item C<extensions> + +From F<Extensions.U>: + +This variable holds a list of all extension files (both C<XS> and +non-xs) installed with the package. It is propagated to F<Config.pm> +and is typically used to test whether a particular extension +is available. + +=item C<extern_C> + +From F<Csym.U>: + +C<ANSI> C requires C<extern> where C++ requires 'extern C<C>'. This +variable can be used in Configure to do the right thing. + +=item C<extras> + +From F<Extras.U>: + +This variable holds a list of extra modules to install. + +=back + +=head2 f + +=over 4 + +=item C<fflushall> + +From F<fflushall.U>: + +This symbol, if defined, tells that to flush +all pending stdio output one must loop through all +the stdio file handles stored in an array and fflush them. +Note that if fflushNULL is defined, fflushall will not +even be probed for and will be left undefined. + +=item C<fflushNULL> + +From F<fflushall.U>: + +This symbol, if defined, tells that fflush(C<NULL>) correctly +flushes all pending stdio output without side effects. In +particular, on some platforms calling fflush(C<NULL>) *still* +corrupts C<STDIN> if it is a pipe. + +=item C<find> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<firstmakefile> + +From F<Unix.U>: + +This variable defines the first file searched by make. On unix, +it is makefile (then Makefile). On case-insensitive systems, +it might be something else. This is only used to deal with +convoluted make depend tricks. + +=item C<flex> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<fpossize> + +From F<fpossize.U>: + +This variable contains the size of a fpostype in bytes. + +=item C<fpostype> + +From F<fpostype.U>: + +This variable defines Fpos_t to be something like fpos_t, long, +uint, or whatever type is used to declare file positions in libc. + +=item C<freetype> + +From F<mallocsrc.U>: + +This variable contains the return type of free(). It is usually +void, but occasionally int. + +=item C<from> + +From F<Cross.U>: + +This variable contains the command used by Configure +to copy files from the target host. Useful and available +only during Perl build. +The string C<:> if not cross-compiling. + +=item C<full_ar> + +From F<Loc_ar.U>: + +This variable contains the full pathname to C<ar>, whether or +not the user has specified C<portability>. This is only used +in the F<Makefile.SH>. + +=item C<full_csh> + +From F<d_csh.U>: + +This variable contains the full pathname to C<csh>, whether or +not the user has specified C<portability>. This is only used +in the compiled C program, and we assume that all systems which +can share this executable will have the same full pathname to +F<csh.> + +=item C<full_sed> + +From F<Loc_sed.U>: + +This variable contains the full pathname to C<sed>, whether or +not the user has specified C<portability>. This is only used +in the compiled C program, and we assume that all systems which +can share this executable will have the same full pathname to +F<sed.> + +=back + +=head2 g + +=over 4 + +=item C<gccansipedantic> + +From F<gccvers.U>: + +If C<GNU> cc (gcc) is used, this variable will enable (if set) the +-ansi and -pedantic ccflags for building core files (through +cflags script). (See F<Porting/pumpkin.pod> for full description). + +=item C<gccosandvers> + +From F<gccvers.U>: + +If C<GNU> cc (gcc) is used, this variable holds the operating system +and version used to compile gcc. It is set to '' if not gcc, +or if nothing useful can be parsed as the os version. + +=item C<gccversion> + +From F<gccvers.U>: + +If C<GNU> cc (gcc) is used, this variable holds C<1> or C<2> to +indicate whether the compiler is version 1 or 2. This is used in +setting some of the default cflags. It is set to '' if not gcc. + +=item C<getgrent_r_proto> + +From F<d_getgrent_r.U>: + +This variable encodes the prototype of getgrent_r. +It is zero if d_getgrent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getgrent_r +is defined. + +=item C<getgrgid_r_proto> + +From F<d_getgrgid_r.U>: + +This variable encodes the prototype of getgrgid_r. +It is zero if d_getgrgid_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getgrgid_r +is defined. + +=item C<getgrnam_r_proto> + +From F<d_getgrnam_r.U>: + +This variable encodes the prototype of getgrnam_r. +It is zero if d_getgrnam_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getgrnam_r +is defined. + +=item C<gethostbyaddr_r_proto> + +From F<d_gethostbyaddr_r.U>: + +This variable encodes the prototype of gethostbyaddr_r. +It is zero if d_gethostbyaddr_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_gethostbyaddr_r +is defined. + +=item C<gethostbyname_r_proto> + +From F<d_gethostbyname_r.U>: + +This variable encodes the prototype of gethostbyname_r. +It is zero if d_gethostbyname_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_gethostbyname_r +is defined. + +=item C<gethostent_r_proto> + +From F<d_gethostent_r.U>: + +This variable encodes the prototype of gethostent_r. +It is zero if d_gethostent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_gethostent_r +is defined. + +=item C<getlogin_r_proto> + +From F<d_getlogin_r.U>: + +This variable encodes the prototype of getlogin_r. +It is zero if d_getlogin_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getlogin_r +is defined. + +=item C<getnetbyaddr_r_proto> + +From F<d_getnetbyaddr_r.U>: + +This variable encodes the prototype of getnetbyaddr_r. +It is zero if d_getnetbyaddr_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getnetbyaddr_r +is defined. + +=item C<getnetbyname_r_proto> + +From F<d_getnetbyname_r.U>: + +This variable encodes the prototype of getnetbyname_r. +It is zero if d_getnetbyname_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getnetbyname_r +is defined. + +=item C<getnetent_r_proto> + +From F<d_getnetent_r.U>: + +This variable encodes the prototype of getnetent_r. +It is zero if d_getnetent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getnetent_r +is defined. + +=item C<getprotobyname_r_proto> + +From F<d_getprotobyname_r.U>: + +This variable encodes the prototype of getprotobyname_r. +It is zero if d_getprotobyname_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getprotobyname_r +is defined. + +=item C<getprotobynumber_r_proto> + +From F<d_getprotobynumber_r.U>: + +This variable encodes the prototype of getprotobynumber_r. +It is zero if d_getprotobynumber_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getprotobynumber_r +is defined. + +=item C<getprotoent_r_proto> + +From F<d_getprotoent_r.U>: + +This variable encodes the prototype of getprotoent_r. +It is zero if d_getprotoent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getprotoent_r +is defined. + +=item C<getpwent_r_proto> + +From F<d_getpwent_r.U>: + +This variable encodes the prototype of getpwent_r. +It is zero if d_getpwent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getpwent_r +is defined. + +=item C<getpwnam_r_proto> + +From F<d_getpwnam_r.U>: + +This variable encodes the prototype of getpwnam_r. +It is zero if d_getpwnam_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getpwnam_r +is defined. + +=item C<getpwuid_r_proto> + +From F<d_getpwuid_r.U>: + +This variable encodes the prototype of getpwuid_r. +It is zero if d_getpwuid_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getpwuid_r +is defined. + +=item C<getservbyname_r_proto> + +From F<d_getservbyname_r.U>: + +This variable encodes the prototype of getservbyname_r. +It is zero if d_getservbyname_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getservbyname_r +is defined. + +=item C<getservbyport_r_proto> + +From F<d_getservbyport_r.U>: + +This variable encodes the prototype of getservbyport_r. +It is zero if d_getservbyport_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getservbyport_r +is defined. + +=item C<getservent_r_proto> + +From F<d_getservent_r.U>: + +This variable encodes the prototype of getservent_r. +It is zero if d_getservent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getservent_r +is defined. + +=item C<getspnam_r_proto> + +From F<d_getspnam_r.U>: + +This variable encodes the prototype of getspnam_r. +It is zero if d_getspnam_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_getspnam_r +is defined. + +=item C<gidformat> + +From F<gidf.U>: + +This variable contains the format string used for printing a Gid_t. + +=item C<gidsign> + +From F<gidsign.U>: + +This variable contains the signedness of a gidtype. +1 for unsigned, -1 for signed. + +=item C<gidsize> + +From F<gidsize.U>: + +This variable contains the size of a gidtype in bytes. + +=item C<gidtype> + +From F<gidtype.U>: + +This variable defines Gid_t to be something like gid_t, int, +ushort, or whatever type is used to declare the return type +of getgid(). Typically, it is the type of group ids in the kernel. + +=item C<glibpth> + +From F<libpth.U>: + +This variable holds the general path (space-separated) used to +find libraries. It may contain directories that do not exist on +this platform, libpth is the cleaned-up version. + +=item C<gmake> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the gmake program. After Configure runs, +the value is reset to a plain C<gmake> and is not useful. + +=item C<gmtime_r_proto> + +From F<d_gmtime_r.U>: + +This variable encodes the prototype of gmtime_r. +It is zero if d_gmtime_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_gmtime_r +is defined. + +=item C<gnulibc_version> + +From F<d_gnulibc.U>: + +This variable contains the version number of the C<GNU> C library. +It is usually something like F<2.2.5>. It is a plain '' if this +is not the C<GNU> C library, or if the version is unknown. + +=item C<grep> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the grep program. After Configure runs, +the value is reset to a plain C<grep> and is not useful. + +=item C<groupcat> + +From F<nis.U>: + +This variable contains a command that produces the text of the +F</etc/group> file. This is normally "cat F</etc/group>", but can be +"ypcat group" when C<NIS> is used. +On some systems, such as os390, there may be no equivalent +command, in which case this variable is unset. + +=item C<groupstype> + +From F<groupstype.U>: + +This variable defines Groups_t to be something like gid_t, int, +ushort, or whatever type is used for the second argument to +getgroups() and setgroups(). Usually, this is the same as +gidtype (gid_t), but sometimes it isn't. + +=item C<gzip> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the gzip program. After Configure runs, +the value is reset to a plain C<gzip> and is not useful. + +=back + +=head2 h + +=over 4 + +=item C<h_fcntl> + +From F<h_fcntl.U>: + +This is variable gets set in various places to tell i_fcntl that +<fcntl.h> should be included. + +=item C<h_sysfile> + +From F<h_sysfile.U>: + +This is variable gets set in various places to tell i_sys_file that +<sys/file.h> should be included. + +=item C<hint> + +From F<Oldconfig.U>: + +Gives the type of hints used for previous answers. May be one of +C<default>, C<recommended> or C<previous>. + +=item C<hostcat> + +From F<nis.U>: + +This variable contains a command that produces the text of the +F</etc/hosts> file. This is normally "cat F</etc/hosts>", but can be +"ypcat hosts" when C<NIS> is used. +On some systems, such as os390, there may be no equivalent +command, in which case this variable is unset. + +=item C<hostgenerate> + +From F<Cross.U>: + +This variable contains the path to a generate_uudmap binary that +can be run on the host C<OS> when cross-compiling. Useful and +available only during Perl build. +Empty string '' if not cross-compiling. + +=item C<hostosname> + +From F<Cross.U>: + +This variable contains the original value of C<$^O> for hostperl +when cross-compiling. This is useful to pick the proper tools +when running build code in the host. +Empty string '' if not cross-compiling. + +=item C<hostperl> + +From F<Cross.U>: + +This variable contains the path to a miniperl binary that can be +run on the host C<OS> when cross-compiling. Useful and available only +during Perl build. +Empty string '' if not cross-compiling. + +=item C<html1dir> + +From F<html1dir.U>: + +This variable contains the name of the directory in which html +source pages are to be put. This directory is for pages +that describe whole programs, not libraries or modules. It +is intended to correspond roughly to section 1 of the Unix +manuals. + +=item C<html1direxp> + +From F<html1dir.U>: + +This variable is the same as the html1dir variable, but is filename +expanded at configuration time, for convenient use in makefiles. + +=item C<html3dir> + +From F<html3dir.U>: + +This variable contains the name of the directory in which html +source pages are to be put. This directory is for pages +that describe libraries or modules. It is intended to +correspond roughly to section 3 of the Unix manuals. + +=item C<html3direxp> + +From F<html3dir.U>: + +This variable is the same as the html3dir variable, but is filename +expanded at configuration time, for convenient use in makefiles. + +=back + +=head2 i + +=over 4 + +=item C<i16size> + +From F<perlxv.U>: + +This variable is the size of an I16 in bytes. + +=item C<i16type> + +From F<perlxv.U>: + +This variable contains the C type used for Perl's I16. + +=item C<i32size> + +From F<perlxv.U>: + +This variable is the size of an I32 in bytes. + +=item C<i32type> + +From F<perlxv.U>: + +This variable contains the C type used for Perl's I32. + +=item C<i64size> + +From F<perlxv.U>: + +This variable is the size of an I64 in bytes. + +=item C<i64type> + +From F<perlxv.U>: + +This variable contains the C type used for Perl's I64. + +=item C<i8size> + +From F<perlxv.U>: + +This variable is the size of an I8 in bytes. + +=item C<i8type> + +From F<perlxv.U>: + +This variable contains the C type used for Perl's I8. + +=item C<i_arpainet> + +From F<i_arpainet.U>: + +This variable conditionally defines the C<I_ARPA_INET> symbol, +and indicates whether a C program should include <arpa/inet.h>. + +=item C<i_bfd> + +From F<i_bfd.U>: + +This variable conditionally defines the C<I_BFD> symbol, and +indicates whether a C program can include <bfd.h>. + +=item C<i_bsdioctl> + +From F<i_sysioctl.U>: + +This variable conditionally defines the C<I_SYS_BSDIOCTL> symbol, which +indicates to the C program that <sys/bsdioctl.h> exists and should +be included. + +=item C<i_crypt> + +From F<i_crypt.U>: + +This variable conditionally defines the C<I_CRYPT> symbol, and indicates +whether a C program should include <crypt.h>. + +=item C<i_db> + +From F<i_db.U>: + +This variable conditionally defines the C<I_DB> symbol, and indicates +whether a C program may include Berkeley's C<DB> include file <db.h>. + +=item C<i_dbm> + +From F<i_dbm.U>: + +This variable conditionally defines the C<I_DBM> symbol, which +indicates to the C program that <dbm.h> exists and should +be included. + +=item C<i_dirent> + +From F<i_dirent.U>: + +This variable conditionally defines C<I_DIRENT>, which indicates +to the C program that it should include <dirent.h>. + +=item C<i_dlfcn> + +From F<i_dlfcn.U>: + +This variable conditionally defines the C<I_DLFCN> symbol, which +indicates to the C program that <dlfcn.h> exists and should +be included. + +=item C<i_execinfo> + +From F<i_execinfo.U>: + +This variable conditionally defines the C<I_EXECINFO> symbol, and indicates +whether a C program may include <execinfo.h>, for backtrace() support. + +=item C<i_fcntl> + +From F<i_fcntl.U>: + +This variable controls the value of C<I_FCNTL> (which tells +the C program to include <fcntl.h>). + +=item C<i_fenv> + +From F<i_fenv.U>: + +This variable conditionally defines the C<I_FENV> symbol, which +indicates to the C program that <fenv.h> exists and should +be included. + +=item C<i_fp> + +From F<i_fp.U>: + +This variable conditionally defines the C<I_FP> symbol, and indicates +whether a C program should include <fp.h>. + +=item C<i_fp_class> + +From F<i_fp_class.U>: + +This variable conditionally defines the C<I_FP_CLASS> symbol, and indicates +whether a C program should include <fp_class.h>. + +=item C<i_gdbm> + +From F<i_gdbm.U>: + +This variable conditionally defines the C<I_GDBM> symbol, which +indicates to the C program that <gdbm.h> exists and should +be included. + +=item C<i_gdbm_ndbm> + +From F<i_ndbm.U>: + +This variable conditionally defines the C<I_GDBM_NDBM> symbol, which +indicates to the C program that <gdbm-F<ndbm.h>> exists and should +be included. This is the location of the F<ndbm.h> compatibility file +in Debian 4.0. + +=item C<i_gdbmndbm> + +From F<i_ndbm.U>: + +This variable conditionally defines the C<I_GDBMNDBM> symbol, which +indicates to the C program that <gdbm/ndbm.h> exists and should +be included. This was the location of the F<ndbm.h> compatibility file +in RedHat 7.1. + +=item C<i_grp> + +From F<i_grp.U>: + +This variable conditionally defines the C<I_GRP> symbol, and indicates +whether a C program should include <grp.h>. + +=item C<i_ieeefp> + +From F<i_ieeefp.U>: + +This variable conditionally defines the C<I_IEEEFP> symbol, and indicates +whether a C program should include <ieeefp.h>. + +=item C<i_inttypes> + +From F<i_inttypes.U>: + +This variable conditionally defines the C<I_INTTYPES> symbol, +and indicates whether a C program should include <inttypes.h>. + +=item C<i_langinfo> + +From F<i_langinfo.U>: + +This variable conditionally defines the C<I_LANGINFO> symbol, +and indicates whether a C program should include <langinfo.h>. + +=item C<i_libutil> + +From F<i_libutil.U>: + +This variable conditionally defines the C<I_LIBUTIL> symbol, and indicates +whether a C program should include <libutil.h>. + +=item C<i_locale> + +From F<i_locale.U>: + +This variable conditionally defines the C<I_LOCALE> symbol, +and indicates whether a C program should include <locale.h>. + +=item C<i_machcthr> + +From F<i_machcthr.U>: + +This variable conditionally defines the C<I_MACH_CTHREADS> symbol, +and indicates whether a C program should include <mach/cthreads.h>. + +=item C<i_malloc> + +From F<i_malloc.U>: + +This variable conditionally defines the C<I_MALLOC> symbol, and indicates +whether a C program should include <malloc.h>. + +=item C<i_mallocmalloc> + +From F<i_mallocmalloc.U>: + +This variable conditionally defines the C<I_MALLOCMALLOC> symbol, +and indicates whether a C program should include <malloc/malloc.h>. + +=item C<i_mntent> + +From F<i_mntent.U>: + +This variable conditionally defines the C<I_MNTENT> symbol, and indicates +whether a C program should include <mntent.h>. + +=item C<i_ndbm> + +From F<i_ndbm.U>: + +This variable conditionally defines the C<I_NDBM> symbol, which +indicates to the C program that <ndbm.h> exists and should +be included. + +=item C<i_netdb> + +From F<i_netdb.U>: + +This variable conditionally defines the C<I_NETDB> symbol, and indicates +whether a C program should include <netdb.h>. + +=item C<i_neterrno> + +From F<i_neterrno.U>: + +This variable conditionally defines the C<I_NET_ERRNO> symbol, which +indicates to the C program that <net/errno.h> exists and should +be included. + +=item C<i_netinettcp> + +From F<i_netinettcp.U>: + +This variable conditionally defines the C<I_NETINET_TCP> symbol, +and indicates whether a C program should include <netinet/tcp.h>. + +=item C<i_niin> + +From F<i_niin.U>: + +This variable conditionally defines C<I_NETINET_IN>, which indicates +to the C program that it should include <netinet/in.h>. Otherwise, +you may try <sys/in.h>. + +=item C<i_poll> + +From F<i_poll.U>: + +This variable conditionally defines the C<I_POLL> symbol, and indicates +whether a C program should include <poll.h>. + +=item C<i_prot> + +From F<i_prot.U>: + +This variable conditionally defines the C<I_PROT> symbol, and indicates +whether a C program should include <prot.h>. + +=item C<i_pthread> + +From F<i_pthread.U>: + +This variable conditionally defines the C<I_PTHREAD> symbol, +and indicates whether a C program should include <pthread.h>. + +=item C<i_pwd> + +From F<i_pwd.U>: + +This variable conditionally defines C<I_PWD>, which indicates +to the C program that it should include <pwd.h>. + +=item C<i_quadmath> + +From F<i_quadmath.U>: + +This variable conditionally defines C<I_QUADMATH>, which indicates +to the C program that it should include <quadmath.h>. + +=item C<i_rpcsvcdbm> + +From F<i_dbm.U>: + +This variable conditionally defines the C<I_RPCSVC_DBM> symbol, which +indicates to the C program that <rpcsvc/dbm.h> exists and should +be included. Some System V systems might need this instead of <dbm.h>. + +=item C<i_sgtty> + +From F<i_termio.U>: + +This variable conditionally defines the C<I_SGTTY> symbol, which +indicates to the C program that it should include <sgtty.h> rather +than <termio.h>. + +=item C<i_shadow> + +From F<i_shadow.U>: + +This variable conditionally defines the C<I_SHADOW> symbol, and indicates +whether a C program should include <shadow.h>. + +=item C<i_socks> + +From F<i_socks.U>: + +This variable conditionally defines the C<I_SOCKS> symbol, and indicates +whether a C program should include <socks.h>. + +=item C<i_stdbool> + +From F<i_stdbool.U>: + +This variable conditionally defines the C<I_STDBOOL> symbol, which +indicates to the C program that <stdbool.h> exists and should +be included. + +=item C<i_stdint> + +From F<i_stdint.U>: + +This variable conditionally defines the C<I_STDINT> symbol, which +indicates to the C program that <stdint.h> exists and should +be included. + +=item C<i_stdlib> + +From F<i_stdlib.U>: + +This variable unconditionally defines the C<I_STDLIB> symbol. + +=item C<i_sunmath> + +From F<i_sunmath.U>: + +This variable conditionally defines the C<I_SUNMATH> symbol, and indicates +whether a C program should include <sunmath.h>. + +=item C<i_sysaccess> + +From F<i_sysaccess.U>: + +This variable conditionally defines the C<I_SYS_ACCESS> symbol, +and indicates whether a C program should include <sys/access.h>. + +=item C<i_sysdir> + +From F<i_sysdir.U>: + +This variable conditionally defines the C<I_SYS_DIR> symbol, and indicates +whether a C program should include <sys/dir.h>. + +=item C<i_sysfile> + +From F<i_sysfile.U>: + +This variable conditionally defines the C<I_SYS_FILE> symbol, and indicates +whether a C program should include <sys/file.h> to get C<R_OK> and friends. + +=item C<i_sysfilio> + +From F<i_sysioctl.U>: + +This variable conditionally defines the C<I_SYS_FILIO> symbol, which +indicates to the C program that <sys/filio.h> exists and should +be included in preference to <sys/ioctl.h>. + +=item C<i_sysin> + +From F<i_niin.U>: + +This variable conditionally defines C<I_SYS_IN>, which indicates +to the C program that it should include <sys/in.h> instead of +<netinet/in.h>. + +=item C<i_sysioctl> + +From F<i_sysioctl.U>: + +This variable conditionally defines the C<I_SYS_IOCTL> symbol, which +indicates to the C program that <sys/ioctl.h> exists and should +be included. + +=item C<i_syslog> + +From F<i_syslog.U>: + +This variable conditionally defines the C<I_SYSLOG> symbol, +and indicates whether a C program should include <syslog.h>. + +=item C<i_sysmman> + +From F<i_sysmman.U>: + +This variable conditionally defines the C<I_SYS_MMAN> symbol, +and indicates whether a C program should include <sys/mman.h>. + +=item C<i_sysmode> + +From F<i_sysmode.U>: + +This variable conditionally defines the C<I_SYSMODE> symbol, +and indicates whether a C program should include <sys/mode.h>. + +=item C<i_sysmount> + +From F<i_sysmount.U>: + +This variable conditionally defines the C<I_SYSMOUNT> symbol, +and indicates whether a C program should include <sys/mount.h>. + +=item C<i_sysndir> + +From F<i_sysndir.U>: + +This variable conditionally defines the C<I_SYS_NDIR> symbol, and indicates +whether a C program should include <sys/ndir.h>. + +=item C<i_sysparam> + +From F<i_sysparam.U>: + +This variable conditionally defines the C<I_SYS_PARAM> symbol, and indicates +whether a C program should include <sys/param.h>. + +=item C<i_syspoll> + +From F<i_syspoll.U>: + +This variable conditionally defines the C<I_SYS_POLL> symbol, which +indicates to the C program that it should include <sys/poll.h>. + +=item C<i_sysresrc> + +From F<i_sysresrc.U>: + +This variable conditionally defines the C<I_SYS_RESOURCE> symbol, +and indicates whether a C program should include <sys/resource.h>. + +=item C<i_syssecrt> + +From F<i_syssecrt.U>: + +This variable conditionally defines the C<I_SYS_SECURITY> symbol, +and indicates whether a C program should include <sys/security.h>. + +=item C<i_sysselct> + +From F<i_sysselct.U>: + +This variable conditionally defines C<I_SYS_SELECT>, which indicates +to the C program that it should include <sys/select.h> in order to +get the definition of struct timeval. + +=item C<i_syssockio> + +From F<i_sysioctl.U>: + +This variable conditionally defines C<I_SYS_SOCKIO> to indicate to the +C program that socket ioctl codes may be found in <sys/sockio.h> +instead of <sys/ioctl.h>. + +=item C<i_sysstat> + +From F<i_sysstat.U>: + +This variable conditionally defines the C<I_SYS_STAT> symbol, +and indicates whether a C program should include <sys/stat.h>. + +=item C<i_sysstatfs> + +From F<i_sysstatfs.U>: + +This variable conditionally defines the C<I_SYSSTATFS> symbol, +and indicates whether a C program should include <sys/statfs.h>. + +=item C<i_sysstatvfs> + +From F<i_sysstatvfs.U>: + +This variable conditionally defines the C<I_SYSSTATVFS> symbol, +and indicates whether a C program should include <sys/statvfs.h>. + +=item C<i_systime> + +From F<i_time.U>: + +This variable conditionally defines C<I_SYS_TIME>, which indicates +to the C program that it should include <sys/time.h>. + +=item C<i_systimek> + +From F<i_time.U>: + +This variable conditionally defines C<I_SYS_TIME_KERNEL>, which +indicates to the C program that it should include <sys/time.h> +with C<KERNEL> defined. + +=item C<i_systimes> + +From F<i_systimes.U>: + +This variable conditionally defines the C<I_SYS_TIMES> symbol, and indicates +whether a C program should include <sys/times.h>. + +=item C<i_systypes> + +From F<i_systypes.U>: + +This variable conditionally defines the C<I_SYS_TYPES> symbol, +and indicates whether a C program should include <sys/types.h>. + +=item C<i_sysuio> + +From F<i_sysuio.U>: + +This variable conditionally defines the C<I_SYSUIO> symbol, and indicates +whether a C program should include <sys/uio.h>. + +=item C<i_sysun> + +From F<i_sysun.U>: + +This variable conditionally defines C<I_SYS_UN>, which indicates +to the C program that it should include <sys/un.h> to get C<UNIX> +domain socket definitions. + +=item C<i_sysutsname> + +From F<i_sysutsname.U>: + +This variable conditionally defines the C<I_SYSUTSNAME> symbol, +and indicates whether a C program should include <sys/utsname.h>. + +=item C<i_sysvfs> + +From F<i_sysvfs.U>: + +This variable conditionally defines the C<I_SYSVFS> symbol, +and indicates whether a C program should include <sys/vfs.h>. + +=item C<i_syswait> + +From F<i_syswait.U>: + +This variable conditionally defines C<I_SYS_WAIT>, which indicates +to the C program that it should include <sys/wait.h>. + +=item C<i_termio> + +From F<i_termio.U>: + +This variable conditionally defines the C<I_TERMIO> symbol, which +indicates to the C program that it should include <termio.h> rather +than <sgtty.h>. + +=item C<i_termios> + +From F<i_termio.U>: + +This variable conditionally defines the C<I_TERMIOS> symbol, which +indicates to the C program that the C<POSIX> <termios.h> file is +to be included. + +=item C<i_time> + +From F<i_time.U>: + +This variable unconditionally defines C<I_TIME>, which indicates +to the C program that it should include <time.h>. + +=item C<i_unistd> + +From F<i_unistd.U>: + +This variable conditionally defines the C<I_UNISTD> symbol, and indicates +whether a C program should include <unistd.h>. + +=item C<i_ustat> + +From F<i_ustat.U>: + +This variable conditionally defines the C<I_USTAT> symbol, and indicates +whether a C program should include <ustat.h>. + +=item C<i_utime> + +From F<i_utime.U>: + +This variable conditionally defines the C<I_UTIME> symbol, and indicates +whether a C program should include <utime.h>. + +=item C<i_vfork> + +From F<i_vfork.U>: + +This variable conditionally defines the C<I_VFORK> symbol, and indicates +whether a C program should include F<vfork.h>. + +=item C<i_wchar> + +From F<i_wchar.U>: + +This variable conditionally defines the C<I_WCHAR> symbol, +that indicates whether a C program may include <wchar.h>. + +=item C<i_wctype> + +From F<i_wctype.U>: + +This variable conditionally defines the C<I_WCTYPE> symbol, +that indicates whether a C program may include <wctype.h>. + +=item C<i_xlocale> + +From F<d_newlocale.U>: + +This symbol, if defined, indicates to the C program that it should +include <xlocale.h> to get uselocale() and its friends + +=item C<ignore_versioned_solibs> + +From F<libs.U>: + +This variable should be non-empty if non-versioned shared +libraries (F<libfoo.so.x.y>) are to be ignored (because they +cannot be linked against). + +=item C<inc_version_list> + +From F<inc_version_list.U>: + +This variable specifies the list of subdirectories in over +which F<perl.c>:incpush() and F<lib/lib.pm> will automatically +search when adding directories to @C<INC>. The elements in +the list are separated by spaces. This is only useful +if you have a perl library directory tree structured like the +default one. See C<INSTALL> for how this works. The versioned +site_perl directory was introduced in 5.005, so that is the +lowest possible value. + +This list includes architecture-dependent directories back to +version $api_versionstring (e.g. 5.5.640) and +architecture-independent directories all the way back to +5.005. + +=item C<inc_version_list_init> + +From F<inc_version_list.U>: + +This variable holds the same list as inc_version_list, but +each item is enclosed in double quotes and separated by commas, +suitable for use in the C<PERL_INC_VERSION_LIST> initialization. + +=item C<incpath> + +From F<usrinc.U>: + +This variable must precede the normal include path to get the +right one, as in F<$incpath/usr/include> or F<$incpath/usr/lib>. +Value can be "" or F</bsd43> on mips. + +=item C<incpth> + +From F<libpth.U>: + +This variable must precede the normal include path to get the +right one, as in F<$incpath/usr/include> or F<$incpath/usr/lib>. +Value can be "" or F</bsd43> on mips. + +=item C<inews> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<initialinstalllocation> + +From F<bin.U>: + +When userelocatableinc is true, this variable holds the location +that make install should copy the perl binary to, with all the +run-time relocatable paths calculated from this at install time. +When used, it is initialized to the original value of binexp, and +then binexp is set to F<.../>, as the other binaries are found +relative to the perl binary. + +=item C<installarchlib> + +From F<archlib.U>: + +This variable is really the same as archlibexp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<installbin> + +From F<bin.U>: + +This variable is the same as binexp unless C<AFS> is running in which case +the user is explicitly prompted for it. This variable should always +be used in your makefiles for maximum portability. + +=item C<installhtml1dir> + +From F<html1dir.U>: + +This variable is really the same as html1direxp, unless you are +using a different installprefix. For extra portability, you +should only use this variable within your makefiles. + +=item C<installhtml3dir> + +From F<html3dir.U>: + +This variable is really the same as html3direxp, unless you are +using a different installprefix. For extra portability, you +should only use this variable within your makefiles. + +=item C<installman1dir> + +From F<man1dir.U>: + +This variable is really the same as man1direxp, unless you are using +C<AFS> in which case it points to the read/write location whereas +man1direxp only points to the read-only access location. For extra +portability, you should only use this variable within your makefiles. + +=item C<installman3dir> + +From F<man3dir.U>: + +This variable is really the same as man3direxp, unless you are using +C<AFS> in which case it points to the read/write location whereas +man3direxp only points to the read-only access location. For extra +portability, you should only use this variable within your makefiles. + +=item C<installprefix> + +From F<installprefix.U>: + +This variable holds the name of the directory below which +"make install" will install the package. For most users, this +is the same as prefix. However, it is useful for +installing the software into a different (usually temporary) +location after which it can be bundled up and moved somehow +to the final location specified by prefix. + +=item C<installprefixexp> + +From F<installprefix.U>: + +This variable holds the full absolute path of installprefix +with all F<~>-expansion done. + +=item C<installprivlib> + +From F<privlib.U>: + +This variable is really the same as privlibexp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<installscript> + +From F<scriptdir.U>: + +This variable is usually the same as scriptdirexp, unless you are on +a system running C<AFS>, in which case they may differ slightly. You +should always use this variable within your makefiles for portability. + +=item C<installsitearch> + +From F<sitearch.U>: + +This variable is really the same as sitearchexp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<installsitebin> + +From F<sitebin.U>: + +This variable is usually the same as sitebinexp, unless you are on +a system running C<AFS>, in which case they may differ slightly. You +should always use this variable within your makefiles for portability. + +=item C<installsitehtml1dir> + +From F<sitehtml1dir.U>: + +This variable is really the same as sitehtml1direxp, unless you are using +C<AFS> in which case it points to the read/write location whereas +html1direxp only points to the read-only access location. For extra +portability, you should only use this variable within your makefiles. + +=item C<installsitehtml3dir> + +From F<sitehtml3dir.U>: + +This variable is really the same as sitehtml3direxp, unless you are using +C<AFS> in which case it points to the read/write location whereas +html3direxp only points to the read-only access location. For extra +portability, you should only use this variable within your makefiles. + +=item C<installsitelib> + +From F<sitelib.U>: + +This variable is really the same as sitelibexp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<installsiteman1dir> + +From F<siteman1dir.U>: + +This variable is really the same as siteman1direxp, unless you are using +C<AFS> in which case it points to the read/write location whereas +man1direxp only points to the read-only access location. For extra +portability, you should only use this variable within your makefiles. + +=item C<installsiteman3dir> + +From F<siteman3dir.U>: + +This variable is really the same as siteman3direxp, unless you are using +C<AFS> in which case it points to the read/write location whereas +man3direxp only points to the read-only access location. For extra +portability, you should only use this variable within your makefiles. + +=item C<installsitescript> + +From F<sitescript.U>: + +This variable is usually the same as sitescriptexp, unless you are on +a system running C<AFS>, in which case they may differ slightly. You +should always use this variable within your makefiles for portability. + +=item C<installstyle> + +From F<installstyle.U>: + +This variable describes the C<style> of the perl installation. +This is intended to be useful for tools that need to +manipulate entire perl distributions. Perl itself doesn't use +this to find its libraries -- the library directories are +stored directly in F<Config.pm>. Currently, there are only two +styles: C<lib> and F<lib/perl5>. The default library locations +(e.g. privlib, sitelib) are either F<$prefix/lib> or +F<$prefix/lib/perl5>. The former is useful if $prefix is a +directory dedicated to perl (e.g. F</opt/perl>), while the latter +is useful if $prefix is shared by many packages, e.g. if +$prefix=F</usr/local>. + +Unfortunately, while this C<style> variable is used to set +defaults for all three directory hierarchies (core, vendor, and +site), there is no guarantee that the same style is actually +appropriate for all those directories. For example, $prefix +might be F</opt/perl>, but $siteprefix might be F</usr/local>. +(Perhaps, in retrospect, the C<lib> style should never have been +supported, but it did seem like a nice idea at the time.) + +The situation is even less clear for tools such as MakeMaker +that can be used to install additional modules into +non-standard places. For example, if a user intends to install +a module into a private directory (perhaps by setting C<PREFIX> on +the F<Makefile.PL> command line), then there is no reason to +assume that the Configure-time $installstyle setting will be +relevant for that C<PREFIX>. + +This may later be extended to include other information, so +be careful with pattern-matching on the results. + +For compatibility with F<perl5.005> and earlier, the default +setting is based on whether or not $prefix contains the string +C<perl>. + +=item C<installusrbinperl> + +From F<instubperl.U>: + +This variable tells whether Perl should be installed also as +F</usr/bin/perl> in addition to +F<$installbin/perl> + +=item C<installvendorarch> + +From F<vendorarch.U>: + +This variable is really the same as vendorarchexp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<installvendorbin> + +From F<vendorbin.U>: + +This variable is really the same as vendorbinexp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<installvendorhtml1dir> + +From F<vendorhtml1dir.U>: + +This variable is really the same as vendorhtml1direxp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<installvendorhtml3dir> + +From F<vendorhtml3dir.U>: + +This variable is really the same as vendorhtml3direxp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<installvendorlib> + +From F<vendorlib.U>: + +This variable is really the same as vendorlibexp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<installvendorman1dir> + +From F<vendorman1dir.U>: + +This variable is really the same as vendorman1direxp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<installvendorman3dir> + +From F<vendorman3dir.U>: + +This variable is really the same as vendorman3direxp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<installvendorscript> + +From F<vendorscript.U>: + +This variable is really the same as vendorscriptexp but may differ on +those systems using C<AFS>. For extra portability, only this variable +should be used in makefiles. + +=item C<intsize> + +From F<intsize.U>: + +This variable contains the value of the C<INTSIZE> symbol, which +indicates to the C program how many bytes there are in an int. + +=item C<issymlink> + +From F<issymlink.U>: + +This variable holds the test command to test for a symbolic link +(if they are supported). Typical values include C<test -h> and +C<test -L>. + +=item C<ivdformat> + +From F<perlxvf.U>: + +This variable contains the format string used for printing +a Perl C<IV> as a signed decimal integer. + +=item C<ivsize> + +From F<perlxv.U>: + +This variable is the size of an C<IV> in bytes. + +=item C<ivtype> + +From F<perlxv.U>: + +This variable contains the C type used for Perl's C<IV>. + +=back + +=head2 k + +=over 4 + +=item C<known_extensions> + +From F<Extensions.U>: + +This variable holds a list of all extensions (both C<XS> and non-xs) +included in the package source distribution. This information is +only really of use during the Perl build, as the list makes no +distinction between extensions which were build and installed, and +those which where not. See C<extensions> for the list of extensions +actually built and available. + +=item C<ksh> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=back + +=head2 l + +=over 4 + +=item C<ld> + +From F<dlsrc.U>: + +This variable indicates the program to be used to link +libraries for dynamic loading. On some systems, it is C<ld>. +On C<ELF> systems, it should be $cc. Mostly, we'll try to respect +the hint file setting. + +=item C<ld_can_script> + +From F<dlsrc.U>: + +This variable shows if the loader accepts scripts in the form of +-Wl,--version-script=F<ld.script>. This is currently only supported +for C<GNU> ld on C<ELF> in dynamic loading builds. + +=item C<lddlflags> + +From F<dlsrc.U>: + +This variable contains any special flags that might need to be +passed to $ld to create a shared library suitable for dynamic +loading. It is up to the makefile to use it. For hpux, it +should be C<-b>. For sunos 4.1, it is empty. + +=item C<ldflags> + +From F<ccflags.U>: + +This variable contains any additional C loader flags desired by +the user. It is up to the Makefile to use this. + +=item C<ldflags_uselargefiles> + +From F<uselfs.U>: + +This variable contains the loader flags needed by large file builds +and added to ldflags by hints files. + +=item C<ldlibpthname> + +From F<libperl.U>: + +This variable holds the name of the shared library +search path, often C<LD_LIBRARY_PATH>. To get an empty +string, the hints file must set this to C<none>. + +=item C<less> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the less program. After Configure runs, +the value is reset to a plain C<less> and is not useful. + +=item C<lib_ext> + +From F<Unix.U>: + +This is an old synonym for _a. + +=item C<libc> + +From F<libc.U>: + +This variable contains the location of the C library. + +=item C<libperl> + +From F<libperl.U>: + +The perl executable is obtained by linking F<perlmain.c> with +libperl, any static extensions (usually just DynaLoader), +and any other libraries needed on this system. libperl +is usually F<libperl.a>, but can also be F<libperl.so.xxx> if +the user wishes to build a perl executable with a shared +library. + +=item C<libpth> + +From F<libpth.U>: + +This variable holds the general path (space-separated) used to find +libraries. It is intended to be used by other units. + +=item C<libs> + +From F<libs.U>: + +This variable holds the additional libraries we want to use. +It is up to the Makefile to deal with it. The list can be empty. + +=item C<libsdirs> + +From F<libs.U>: + +This variable holds the directory names aka dirnames of the libraries +we found and accepted, duplicates are removed. + +=item C<libsfiles> + +From F<libs.U>: + +This variable holds the filenames aka basenames of the libraries +we found and accepted. + +=item C<libsfound> + +From F<libs.U>: + +This variable holds the full pathnames of the libraries +we found and accepted. + +=item C<libspath> + +From F<libs.U>: + +This variable holds the directory names probed for libraries. + +=item C<libswanted> + +From F<Myinit.U>: + +This variable holds a list of all the libraries we want to +search. The order is chosen to pick up the c library +ahead of ucb or bsd libraries for SVR4. + +=item C<libswanted_uselargefiles> + +From F<uselfs.U>: + +This variable contains the libraries needed by large file builds +and added to ldflags by hints files. It is a space separated list +of the library names without the C<lib> prefix or any suffix, just +like F<libswanted.>. + +=item C<line> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<lint> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<lkflags> + +From F<ccflags.U>: + +This variable contains any additional C partial linker flags desired by +the user. It is up to the Makefile to use this. + +=item C<ln> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the ln program. After Configure runs, +the value is reset to a plain C<ln> and is not useful. + +=item C<lns> + +From F<lns.U>: + +This variable holds the name of the command to make +symbolic links (if they are supported). It can be used +in the Makefile. It is either C<ln -s> or C<ln> + +=item C<localtime_r_proto> + +From F<d_localtime_r.U>: + +This variable encodes the prototype of localtime_r. +It is zero if d_localtime_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_localtime_r +is defined. + +=item C<locincpth> + +From F<ccflags.U>: + +This variable contains a list of additional directories to be +searched by the compiler. The appropriate C<-I> directives will +be added to ccflags. This is intended to simplify setting +local directories from the Configure command line. +It's not much, but it parallels the loclibpth stuff in F<libpth.U>. + +=item C<loclibpth> + +From F<libpth.U>: + +This variable holds the paths (space-separated) used to find local +libraries. It is prepended to libpth, and is intended to be easily +set from the command line. + +=item C<longdblinfbytes> + +From F<infnan.U>: + +This variable contains comma-separated list of hexadecimal bytes +for the long double precision infinity. + +=item C<longdblkind> + +From F<d_longdbl.U>: + +This variable, if defined, encodes the type of a long double: +0 = double, +1 = C<IEEE> 754 128-bit little endian, +2 = C<IEEE> 754 128-bit big endian, +3 = x86 80-bit little endian, +4 = x86 80-bit big endian, +5 = double-double 128-bit little endian, +6 = double-double 128-bit big endian, +7 = 128-bit mixed-endian double-double (64-bit LEs in C<BE>), +8 = 128-bit mixed-endian double-double (64-bit BEs in C<LE>), +9 = 128-bit C<PDP>-style mixed-endian long doubles, +-1 = unknown format. + +=item C<longdblmantbits> + +From F<mantbits.U>: + +This symbol, if defined, tells how many mantissa bits +there are in long double precision floating point format. +Note that this can be C<LDBL_MANT_DIG> minus one, +since C<LDBL_MANT_DIG> can include the C<IEEE> 754 implicit bit. +The common x86-style 80-bit long double does not have +an implicit bit. + +=item C<longdblnanbytes> + +From F<infnan.U>: + +This variable contains comma-separated list of hexadecimal bytes +for the long double precision not-a-number. + +=item C<longdblsize> + +From F<d_longdbl.U>: + +This variable contains the value of the C<LONG_DOUBLESIZE> symbol, which +indicates to the C program how many bytes there are in a long double, +if this system supports long doubles. Note that this is +sizeof(long double), which may include unused bytes. + +=item C<longlongsize> + +From F<d_longlong.U>: + +This variable contains the value of the C<LONGLONGSIZE> symbol, which +indicates to the C program how many bytes there are in a long long, +if this system supports long long. + +=item C<longsize> + +From F<intsize.U>: + +This variable contains the value of the C<LONGSIZE> symbol, which +indicates to the C program how many bytes there are in a long. + +=item C<lp> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<lpr> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<ls> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the ls program. After Configure runs, +the value is reset to a plain C<ls> and is not useful. + +=item C<lseeksize> + +From F<lseektype.U>: + +This variable defines lseektype to be something like off_t, long, +or whatever type is used to declare lseek offset's type in the +kernel (which also appears to be lseek's return type). + +=item C<lseektype> + +From F<lseektype.U>: + +This variable defines lseektype to be something like off_t, long, +or whatever type is used to declare lseek offset's type in the +kernel (which also appears to be lseek's return type). + +=back + +=head2 m + +=over 4 + +=item C<mail> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<mailx> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<make> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the make program. After Configure runs, +the value is reset to a plain C<make> and is not useful. + +=item C<make_set_make> + +From F<make.U>: + +Some versions of C<make> set the variable C<MAKE>. Others do not. +This variable contains the string to be included in F<Makefile.SH> +so that C<MAKE> is set if needed, and not if not needed. +Possible values are: + +make_set_make=C<#> # If your make program handles this for you, + +make_set_make=C<MAKE=$make> # if it doesn't. + +This uses a comment character so that we can distinguish a +C<set> value (from a previous F<config.sh> or Configure C<-D> option) +from an uncomputed value. + +=item C<mallocobj> + +From F<mallocsrc.U>: + +This variable contains the name of the F<malloc.o> that this package +generates, if that F<malloc.o> is preferred over the system malloc. +Otherwise the value is null. This variable is intended for generating +Makefiles. See mallocsrc. + +=item C<mallocsrc> + +From F<mallocsrc.U>: + +This variable contains the name of the F<malloc.c> that comes with +the package, if that F<malloc.c> is preferred over the system malloc. +Otherwise the value is null. This variable is intended for generating +Makefiles. + +=item C<malloctype> + +From F<mallocsrc.U>: + +This variable contains the kind of ptr returned by malloc and realloc. + +=item C<man1dir> + +From F<man1dir.U>: + +This variable contains the name of the directory in which manual +source pages are to be put. It is the responsibility of the +F<Makefile.SH> to get the value of this into the proper command. +You must be prepared to do the F<~name> expansion yourself. + +=item C<man1direxp> + +From F<man1dir.U>: + +This variable is the same as the man1dir variable, but is filename +expanded at configuration time, for convenient use in makefiles. + +=item C<man1ext> + +From F<man1dir.U>: + +This variable contains the extension that the manual page should +have: one of C<n>, C<l>, or C<1>. The Makefile must supply the F<.>. +See man1dir. + +=item C<man3dir> + +From F<man3dir.U>: + +This variable contains the name of the directory in which manual +source pages are to be put. It is the responsibility of the +F<Makefile.SH> to get the value of this into the proper command. +You must be prepared to do the F<~name> expansion yourself. + +=item C<man3direxp> + +From F<man3dir.U>: + +This variable is the same as the man3dir variable, but is filename +expanded at configuration time, for convenient use in makefiles. + +=item C<man3ext> + +From F<man3dir.U>: + +This variable contains the extension that the manual page should +have: one of C<n>, C<l>, or C<3>. The Makefile must supply the F<.>. +See man3dir. + +=item C<mips_type> + +From F<usrinc.U>: + +This variable holds the environment type for the mips system. +Possible values are "BSD 4.3" and "System V". + +=item C<mistrustnm> + +From F<Csym.U>: + +This variable can be used to establish a fallthrough for the cases +where nm fails to find a symbol. If usenm is false or usenm is true +and mistrustnm is false, this variable has no effect. If usenm is true +and mistrustnm is C<compile>, a test program will be compiled to try to +find any symbol that can't be located via nm lookup. If mistrustnm is +C<run>, the test program will be run as well as being compiled. + +=item C<mkdir> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the mkdir program. After Configure runs, +the value is reset to a plain C<mkdir> and is not useful. + +=item C<mmaptype> + +From F<d_mmap.U>: + +This symbol contains the type of pointer returned by mmap() +(and simultaneously the type of the first argument). +It can be C<void *> or C<caddr_t>. + +=item C<modetype> + +From F<modetype.U>: + +This variable defines modetype to be something like mode_t, +int, unsigned short, or whatever type is used to declare file +modes for system calls. + +=item C<more> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the more program. After Configure runs, +the value is reset to a plain C<more> and is not useful. + +=item C<multiarch> + +From F<multiarch.U>: + +This variable conditionally defines the C<MULTIARCH> symbol +which signifies the presence of multiplatform files. +This is normally set by hints files. + +=item C<mv> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<myarchname> + +From F<archname.U>: + +This variable holds the architecture name computed by Configure in +a previous run. It is not intended to be perused by any user and +should never be set in a hint file. + +=item C<mydomain> + +From F<myhostname.U>: + +This variable contains the eventual value of the C<MYDOMAIN> symbol, +which is the domain of the host the program is going to run on. +The domain must be appended to myhostname to form a complete host name. +The dot comes with mydomain, and need not be supplied by the program. + +=item C<myhostname> + +From F<myhostname.U>: + +This variable contains the eventual value of the C<MYHOSTNAME> symbol, +which is the name of the host the program is going to run on. +The domain is not kept with hostname, but must be gotten from mydomain. +The dot comes with mydomain, and need not be supplied by the program. + +=item C<myuname> + +From F<Oldconfig.U>: + +The output of C<uname -a> if available, otherwise the hostname. +The whole thing is then lower-cased and slashes and single quotes are +removed. + +=back + +=head2 n + +=over 4 + +=item C<n> + +From F<n.U>: + +This variable contains the C<-n> flag if that is what causes the echo +command to suppress newline. Otherwise it is null. Correct usage is +$echo $n "prompt for a question: $c". + +=item C<need_va_copy> + +From F<need_va_copy.U>: + +This symbol, if defined, indicates that the system stores +the variable argument list datatype, va_list, in a format +that cannot be copied by simple assignment, so that some +other means must be used when copying is required. +As such systems vary in their provision (or non-provision) +of copying mechanisms, F<handy.h> defines a platform- +C<independent> macro, Perl_va_copy(src, dst), to do the job. + +=item C<netdb_hlen_type> + +From F<netdbtype.U>: + +This variable holds the type used for the 2nd argument to +gethostbyaddr(). Usually, this is int or size_t or unsigned. +This is only useful if you have gethostbyaddr(), naturally. + +=item C<netdb_host_type> + +From F<netdbtype.U>: + +This variable holds the type used for the 1st argument to +gethostbyaddr(). Usually, this is char * or void *, possibly +with or without a const prefix. +This is only useful if you have gethostbyaddr(), naturally. + +=item C<netdb_name_type> + +From F<netdbtype.U>: + +This variable holds the type used for the argument to +gethostbyname(). Usually, this is char * or const char *. +This is only useful if you have gethostbyname(), naturally. + +=item C<netdb_net_type> + +From F<netdbtype.U>: + +This variable holds the type used for the 1st argument to +getnetbyaddr(). Usually, this is int or long. +This is only useful if you have getnetbyaddr(), naturally. + +=item C<nm> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the nm program. After Configure runs, +the value is reset to a plain C<nm> and is not useful. + +=item C<nm_opt> + +From F<usenm.U>: + +This variable holds the options that may be necessary for nm. + +=item C<nm_so_opt> + +From F<usenm.U>: + +This variable holds the options that may be necessary for nm +to work on a shared library but that can not be used on an +archive library. Currently, this is only used by Linux, where +nm --dynamic is *required* to get symbols from an C<ELF> library which +has been stripped, but nm --dynamic is *fatal* on an archive library. +Maybe Linux should just always set usenm=false. + +=item C<nonxs_ext> + +From F<Extensions.U>: + +This variable holds a list of all non-xs extensions built and +installed by the package. By default, all non-xs extensions +distributed will be built, with the exception of platform-specific +extensions (currently only one C<VMS> specific extension). + +=item C<nroff> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the nroff program. After Configure runs, +the value is reset to a plain C<nroff> and is not useful. + +=item C<nv_overflows_integers_at> + +From F<perlxv.U>: + +This variable gives the largest integer value that NVs can hold +as a constant floating point expression. +If it could not be determined, it holds the value 0. + +=item C<nv_preserves_uv_bits> + +From F<perlxv.U>: + +This variable indicates how many of bits type uvtype +a variable nvtype can preserve. + +=item C<nveformat> + +From F<perlxvf.U>: + +This variable contains the format string used for printing +a Perl C<NV> using %e-ish floating point format. + +=item C<nvEUformat> + +From F<perlxvf.U>: + +This variable contains the format string used for printing +a Perl C<NV> using %E-ish floating point format. + +=item C<nvfformat> + +From F<perlxvf.U>: + +This variable contains the format string used for printing +a Perl C<NV> using %f-ish floating point format. + +=item C<nvFUformat> + +From F<perlxvf.U>: + +This variable contains the format string used for printing +a Perl C<NV> using %F-ish floating point format. + +=item C<nvgformat> + +From F<perlxvf.U>: + +This variable contains the format string used for printing +a Perl C<NV> using %g-ish floating point format. + +=item C<nvGUformat> + +From F<perlxvf.U>: + +This variable contains the format string used for printing +a Perl C<NV> using %G-ish floating point format. + +=item C<nvmantbits> + +From F<mantbits.U>: + +This variable tells how many bits the mantissa of a Perl C<NV> has, +not including the possible implicit bit. + +=item C<nvsize> + +From F<perlxv.U>: + +This variable is the size of a Perl C<NV> in bytes. +Note that some floating point formats have unused bytes. + +=item C<nvtype> + +From F<perlxv.U>: + +This variable contains the C type used for Perl's C<NV>. + +=back + +=head2 o + +=over 4 + +=item C<o_nonblock> + +From F<nblock_io.U>: + +This variable bears the symbol value to be used during open() or fcntl() +to turn on non-blocking I/O for a file descriptor. If you wish to switch +between blocking and non-blocking, you may try ioctl(C<FIOSNBIO>) instead, +but that is only supported by some devices. + +=item C<obj_ext> + +From F<Unix.U>: + +This is an old synonym for _o. + +=item C<old_pthread_create_joinable> + +From F<d_pthrattrj.U>: + +This variable defines the constant to use for creating joinable +(aka undetached) pthreads. Unused if F<pthread.h> defines +C<PTHREAD_CREATE_JOINABLE>. If used, possible values are +C<PTHREAD_CREATE_UNDETACHED> and C<__UNDETACHED>. + +=item C<optimize> + +From F<ccflags.U>: + +This variable contains any F<optimizer/debugger> flag that should be used. +It is up to the Makefile to use it. + +=item C<orderlib> + +From F<orderlib.U>: + +This variable is C<true> if the components of libraries must be ordered +(with `lorder $* | tsort`) before placing them in an archive. Set to +C<false> if ranlib or ar can generate random libraries. + +=item C<osname> + +From F<Oldconfig.U>: + +This variable contains the operating system name (e.g. sunos, +solaris, hpux, etc.). It can be useful later on for setting +defaults. Any spaces are replaced with underscores. It is set +to a null string if we can't figure it out. + +=item C<osvers> + +From F<Oldconfig.U>: + +This variable contains the operating system version (e.g. +4.1.3, 5.2, etc.). It is primarily used for helping select +an appropriate hints file, but might be useful elsewhere for +setting defaults. It is set to '' if we can't figure it out. +We try to be flexible about how much of the version number +to keep, e.g. if 4.1.1, 4.1.2, and 4.1.3 are essentially the +same for this package, hints files might just be F<os_4.0> or +F<os_4.1>, etc., not keeping separate files for each little release. + +=item C<otherlibdirs> + +From F<otherlibdirs.U>: + +This variable contains a colon-separated set of paths for the perl +binary to search for additional library files or modules. +These directories will be tacked to the end of @C<INC>. +Perl will automatically search below each path for version- +and architecture-specific directories. See inc_version_list +for more details. +A value of C< > means C<none> and is used to preserve this value +for the next run through Configure. + +=back + +=head2 p + +=over 4 + +=item C<package> + +From F<package.U>: + +This variable contains the name of the package being constructed. +It is primarily intended for the use of later Configure units. + +=item C<pager> + +From F<pager.U>: + +This variable contains the name of the preferred pager on the system. +Usual values are (the full pathnames of) more, less, pg, or cat. + +=item C<passcat> + +From F<nis.U>: + +This variable contains a command that produces the text of the +F</etc/passwd> file. This is normally "cat F</etc/passwd>", but can be +"ypcat passwd" when C<NIS> is used. +On some systems, such as os390, there may be no equivalent +command, in which case this variable is unset. + +=item C<patchlevel> + +From F<patchlevel.U>: + +The patchlevel level of this package. +The value of patchlevel comes from the F<patchlevel.h> file. +In a version number such as 5.6.1, this is the C<6>. +In F<patchlevel.h>, this is referred to as C<PERL_VERSION>. + +=item C<path_sep> + +From F<Unix.U>: + +This is an old synonym for p_ in F<Head.U>, the character +used to separate elements in the command shell search C<PATH>. + +=item C<perl> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the perl program. After Configure runs, +the value is reset to a plain C<perl> and is not useful. + +=item C<perl5> + +From F<perl5.U>: + +This variable contains the full path (if any) to a previously +installed F<perl5.005> or later suitable for running the script +to determine inc_version_list. + +=back + +=head2 P + +=over 4 + +=item C<PERL_API_REVISION> + +From F<patchlevel.h>: + +This number describes the earliest compatible C<PERL_REVISION> of +Perl (C<compatibility> here being defined as sufficient F<binary/C<API>> +compatibility to run C<XS> code built with the older version). +Normally this does not change across maintenance releases. +Please read the comment in F<patchlevel.h>. + +=item C<PERL_API_SUBVERSION> + +From F<patchlevel.h>: + +This number describes the earliest compatible C<PERL_SUBVERSION> of +Perl (C<compatibility> here being defined as sufficient F<binary/C<API>> +compatibility to run C<XS> code built with the older version). +Normally this does not change across maintenance releases. +Please read the comment in F<patchlevel.h>. + +=item C<PERL_API_VERSION> + +From F<patchlevel.h>: + +This number describes the earliest compatible C<PERL_VERSION> of +Perl (C<compatibility> here being defined as sufficient F<binary/C<API>> +compatibility to run C<XS> code built with the older version). +Normally this does not change across maintenance releases. +Please read the comment in F<patchlevel.h>. + +=item C<PERL_CONFIG_SH> + +From F<Oldsyms.U>: + +This is set to C<true> in F<config.sh> so that a shell script +sourcing F<config.sh> can tell if it has been sourced already. + +=item C<PERL_PATCHLEVEL> + +From F<Oldsyms.U>: + +This symbol reflects the patchlevel, if available. Will usually +come from the F<.patch> file, which is available when the perl +source tree was fetched with rsync. + +=item C<perl_patchlevel> + +From F<patchlevel.U>: + +This is the Perl patch level, a numeric change identifier, +as defined by whichever source code maintenance system +is used to maintain the patches; currently Perforce. +It does not correlate with the Perl version numbers or +the maintenance versus development dichotomy except +by also being increasing. + +=item C<PERL_REVISION> + +From F<Oldsyms.U>: + +In a Perl version number such as 5.6.2, this is the 5. +This value is manually set in F<patchlevel.h> + +=item C<perl_static_inline> + +From F<d_static_inline.U>: + +This variable defines the C<PERL_STATIC_INLINE> symbol to +the best-guess incantation to use for static inline functions. +Possibilities include +static inline (c99) +static __inline__ (gcc -ansi) +static __inline (C<MSVC>) +static _inline (older C<MSVC>) +static (c89 compilers) + +=item C<PERL_SUBVERSION> + +From F<Oldsyms.U>: + +In a Perl version number such as 5.6.2, this is the 2. +Values greater than 50 represent potentially unstable +development subversions. +This value is manually set in F<patchlevel.h> + +=item C<PERL_VERSION> + +From F<Oldsyms.U>: + +In a Perl version number such as 5.6.2, this is the 6. +This value is manually set in F<patchlevel.h> + +=item C<perladmin> + +From F<perladmin.U>: + +Electronic mail address of the perl5 administrator. + +=item C<perllibs> + +From F<End.U>: + +The list of libraries needed by Perl only (any libraries needed +by extensions only will by dropped, if using dynamic loading). + +=item C<perlpath> + +From F<perlpath.U>: + +This variable contains the eventual value of the C<PERLPATH> symbol, +which contains the name of the perl interpreter to be used in +shell scripts and in the "eval C<exec>" idiom. This variable is +not necessarily the pathname of the file containing the perl +interpreter; you must append the executable extension (_exe) if +it is not already present. Note that Perl code that runs during +the Perl build process cannot reference this variable, as Perl +may not have been installed, or even if installed, may be a +different version of Perl. + +=item C<pg> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the pg program. After Configure runs, +the value is reset to a plain C<pg> and is not useful. + +=item C<phostname> + +From F<myhostname.U>: + +This variable contains the eventual value of the C<PHOSTNAME> symbol, +which is a command that can be fed to popen() to get the host name. +The program should probably not presume that the domain is or isn't +there already. + +=item C<pidtype> + +From F<pidtype.U>: + +This variable defines C<PIDTYPE> to be something like pid_t, int, +ushort, or whatever type is used to declare process ids in the kernel. + +=item C<plibpth> + +From F<libpth.U>: + +Holds the private path used by Configure to find out the libraries. +Its value is prepend to libpth. This variable takes care of special +machines, like the mips. Usually, it should be empty. + +=item C<pmake> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<pr> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<prefix> + +From F<prefix.U>: + +This variable holds the name of the directory below which the +user will install the package. Usually, this is F</usr/local>, and +executables go in F</usr/local/bin>, library stuff in F</usr/local/lib>, +man pages in F</usr/local/man>, etc. It is only used to set defaults +for things in F<bin.U>, F<mansrc.U>, F<privlib.U>, or F<scriptdir.U>. + +=item C<prefixexp> + +From F<prefix.U>: + +This variable holds the full absolute path of the directory below +which the user will install the package. Derived from prefix. + +=item C<privlib> + +From F<privlib.U>: + +This variable contains the eventual value of the C<PRIVLIB> symbol, +which is the name of the private library for this package. It may +have a F<~> on the front. It is up to the makefile to eventually create +this directory while performing installation (with F<~> substitution). + +=item C<privlibexp> + +From F<privlib.U>: + +This variable is the F<~name> expanded version of privlib, so that you +may use it directly in Makefiles or shell scripts. + +=item C<procselfexe> + +From F<d_procselfexe.U>: + +If d_procselfexe is defined, $procselfexe is the filename +of the symbolic link pointing to the absolute pathname of +the executing program. + +=item C<ptrsize> + +From F<ptrsize.U>: + +This variable contains the value of the C<PTRSIZE> symbol, which +indicates to the C program how many bytes there are in a pointer. + +=back + +=head2 q + +=over 4 + +=item C<quadkind> + +From F<quadtype.U>: + +This variable, if defined, encodes the type of a quad: +1 = int, 2 = long, 3 = long long, 4 = int64_t. + +=item C<quadtype> + +From F<quadtype.U>: + +This variable defines Quad_t to be something like long, int, +long long, int64_t, or whatever type is used for 64-bit integers. + +=back + +=head2 r + +=over 4 + +=item C<randbits> + +From F<randfunc.U>: + +Indicates how many bits are produced by the function used to +generate normalized random numbers. + +=item C<randfunc> + +From F<randfunc.U>: + +Indicates the name of the random number function to use. +Values include drand48, random, and rand. In C programs, +the C<Drand01> macro is defined to generate uniformly distributed +random numbers over the range [0., 1.[ (see drand01 and nrand). + +=item C<random_r_proto> + +From F<d_random_r.U>: + +This variable encodes the prototype of random_r. +It is zero if d_random_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_random_r +is defined. + +=item C<randseedtype> + +From F<randfunc.U>: + +Indicates the type of the argument of the seedfunc. + +=item C<ranlib> + +From F<orderlib.U>: + +This variable is set to the pathname of the ranlib program, if it is +needed to generate random libraries. Set to C<:> if ar can generate +random libraries or if random libraries are not supported + +=item C<rd_nodata> + +From F<nblock_io.U>: + +This variable holds the return code from read() when no data is +present. It should be -1, but some systems return 0 when C<O_NDELAY> is +used, which is a shame because you cannot make the difference between +no data and an F<EOF.>. Sigh! + +=item C<readdir64_r_proto> + +From F<d_readdir64_r.U>: + +This variable encodes the prototype of readdir64_r. +It is zero if d_readdir64_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_readdir64_r +is defined. + +=item C<readdir_r_proto> + +From F<d_readdir_r.U>: + +This variable encodes the prototype of readdir_r. +It is zero if d_readdir_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_readdir_r +is defined. + +=item C<revision> + +From F<patchlevel.U>: + +The value of revision comes from the F<patchlevel.h> file. +In a version number such as 5.6.1, this is the C<5>. +In F<patchlevel.h>, this is referred to as C<PERL_REVISION>. + +=item C<rm> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the rm program. After Configure runs, +the value is reset to a plain C<rm> and is not useful. + +=item C<rm_try> + +From F<Unix.U>: + +This is a cleanup variable for try test programs. +Internal Configure use only. + +=item C<rmail> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<run> + +From F<Cross.U>: + +This variable contains the command used by Configure +to copy and execute a cross-compiled executable in the +target host. Useful and available only during Perl build. +Empty string '' if not cross-compiling. + +=item C<runnm> + +From F<usenm.U>: + +This variable contains C<true> or C<false> depending whether the +nm extraction should be performed or not, according to the value +of usenm and the flags on the Configure command line. + +=back + +=head2 s + +=over 4 + +=item C<sched_yield> + +From F<d_pthread_y.U>: + +This variable defines the way to yield the execution +of the current thread. + +=item C<scriptdir> + +From F<scriptdir.U>: + +This variable holds the name of the directory in which the user wants +to put publicly scripts for the package in question. It is either +the same directory as for binaries, or a special one that can be +mounted across different architectures, like F</usr/share>. Programs +must be prepared to deal with F<~name> expansion. + +=item C<scriptdirexp> + +From F<scriptdir.U>: + +This variable is the same as scriptdir, but is filename expanded +at configuration time, for programs not wanting to bother with it. + +=item C<sed> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the sed program. After Configure runs, +the value is reset to a plain C<sed> and is not useful. + +=item C<seedfunc> + +From F<randfunc.U>: + +Indicates the random number generating seed function. +Values include srand48, srandom, and srand. + +=item C<selectminbits> + +From F<selectminbits.U>: + +This variable holds the minimum number of bits operated by select. +That is, if you do select(n, ...), how many bits at least will be +cleared in the masks if some activity is detected. Usually this +is either n or 32*ceil(F<n/32>), especially many little-endians do +the latter. This is only useful if you have select(), naturally. + +=item C<selecttype> + +From F<selecttype.U>: + +This variable holds the type used for the 2nd, 3rd, and 4th +arguments to select. Usually, this is C<fd_set *>, if C<HAS_FD_SET> +is defined, and C<int *> otherwise. This is only useful if you +have select(), naturally. + +=item C<sendmail> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<setgrent_r_proto> + +From F<d_setgrent_r.U>: + +This variable encodes the prototype of setgrent_r. +It is zero if d_setgrent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setgrent_r +is defined. + +=item C<sethostent_r_proto> + +From F<d_sethostent_r.U>: + +This variable encodes the prototype of sethostent_r. +It is zero if d_sethostent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_sethostent_r +is defined. + +=item C<setlocale_r_proto> + +From F<d_setlocale_r.U>: + +This variable encodes the prototype of setlocale_r. +It is zero if d_setlocale_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setlocale_r +is defined. + +=item C<setnetent_r_proto> + +From F<d_setnetent_r.U>: + +This variable encodes the prototype of setnetent_r. +It is zero if d_setnetent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setnetent_r +is defined. + +=item C<setprotoent_r_proto> + +From F<d_setprotoent_r.U>: + +This variable encodes the prototype of setprotoent_r. +It is zero if d_setprotoent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setprotoent_r +is defined. + +=item C<setpwent_r_proto> + +From F<d_setpwent_r.U>: + +This variable encodes the prototype of setpwent_r. +It is zero if d_setpwent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setpwent_r +is defined. + +=item C<setservent_r_proto> + +From F<d_setservent_r.U>: + +This variable encodes the prototype of setservent_r. +It is zero if d_setservent_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_setservent_r +is defined. + +=item C<sGMTIME_max> + +From F<time_size.U>: + +This variable defines the maximum value of the time_t offset that +the system function gmtime () accepts + +=item C<sGMTIME_min> + +From F<time_size.U>: + +This variable defines the minimum value of the time_t offset that +the system function gmtime () accepts + +=item C<sh> + +From F<sh.U>: + +This variable contains the full pathname of the shell used +on this system to execute Bourne shell scripts. Usually, this will be +F</bin/sh>, though it's possible that some systems will have F</bin/ksh>, +F</bin/pdksh>, F</bin/ash>, F</bin/bash>, or even something such as +D:F</bin/sh.exe>. +This unit comes before F<Options.U>, so you can't set sh with a C<-D> +option, though you can override this (and startsh) +with C<-O -Dsh=F</bin/whatever> -Dstartsh=whatever> + +=item C<shar> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<sharpbang> + +From F<spitshell.U>: + +This variable contains the string #! if this system supports that +construct. + +=item C<shmattype> + +From F<d_shmat.U>: + +This symbol contains the type of pointer returned by shmat(). +It can be C<void *> or C<char *>. + +=item C<shortsize> + +From F<intsize.U>: + +This variable contains the value of the C<SHORTSIZE> symbol which +indicates to the C program how many bytes there are in a short. + +=item C<shrpenv> + +From F<libperl.U>: + +If the user builds a shared F<libperl.so>, then we need to tell the +C<perl> executable where it will be able to find the installed F<libperl.so>. +One way to do this on some systems is to set the environment variable +C<LD_RUN_PATH> to the directory that will be the final location of the +shared F<libperl.so>. The makefile can use this with something like +$shrpenv $(C<CC>) -o perl F<perlmain.o> $libperl $libs +Typical values are +shrpenv="env C<LD_RUN_PATH>=F<$archlibexp/C<CORE>>" +or +shrpenv='' +See the main perl F<Makefile.SH> for actual working usage. + +Alternatively, we might be able to use a command line option such +as -R F<$archlibexp/C<CORE>> (Solaris) or -Wl,-rpath +F<$archlibexp/C<CORE>> (Linux). + +=item C<shsharp> + +From F<spitshell.U>: + +This variable tells further Configure units whether your sh can +handle # comments. + +=item C<sig_count> + +From F<sig_name.U>: + +This variable holds a number larger than the largest valid +signal number. This is usually the same as the C<NSIG> macro. + +=item C<sig_name> + +From F<sig_name.U>: + +This variable holds the signal names, space separated. The leading +C<SIG> in signal name is removed. A C<ZERO> is prepended to the list. +This is currently not used, sig_name_init is used instead. + +=item C<sig_name_init> + +From F<sig_name.U>: + +This variable holds the signal names, enclosed in double quotes and +separated by commas, suitable for use in the C<SIG_NAME> definition +below. A C<ZERO> is prepended to the list, and the list is +terminated with a plain 0. The leading C<SIG> in signal names +is removed. See sig_num. + +=item C<sig_num> + +From F<sig_name.U>: + +This variable holds the signal numbers, space separated. A C<ZERO> is +prepended to the list (corresponding to the fake C<SIGZERO>). +Those numbers correspond to the value of the signal listed +in the same place within the sig_name list. +This is currently not used, sig_num_init is used instead. + +=item C<sig_num_init> + +From F<sig_name.U>: + +This variable holds the signal numbers, enclosed in double quotes and +separated by commas, suitable for use in the C<SIG_NUM> definition +below. A C<ZERO> is prepended to the list, and the list is +terminated with a plain 0. + +=item C<sig_size> + +From F<sig_name.U>: + +This variable contains the number of elements of the sig_name +and sig_num arrays. + +=item C<signal_t> + +From F<d_voidsig.U>: + +This variable holds the type of the signal handler (void or int). + +=item C<sitearch> + +From F<sitearch.U>: + +This variable contains the eventual value of the C<SITEARCH> symbol, +which is the name of the private library for this package. It may +have a F<~> on the front. It is up to the makefile to eventually create +this directory while performing installation (with F<~> substitution). +The standard distribution will put nothing in this directory. +After perl has been installed, users may install their own local +architecture-dependent modules in this directory with +MakeMaker F<Makefile.PL> +or equivalent. See C<INSTALL> for details. + +=item C<sitearchexp> + +From F<sitearch.U>: + +This variable is the F<~name> expanded version of sitearch, so that you +may use it directly in Makefiles or shell scripts. + +=item C<sitebin> + +From F<sitebin.U>: + +This variable holds the name of the directory in which the user wants +to put add-on publicly executable files for the package in question. It +is most often a local directory such as F</usr/local/bin>. Programs using +this variable must be prepared to deal with F<~name> substitution. +The standard distribution will put nothing in this directory. +After perl has been installed, users may install their own local +executables in this directory with +MakeMaker F<Makefile.PL> +or equivalent. See C<INSTALL> for details. + +=item C<sitebinexp> + +From F<sitebin.U>: + +This is the same as the sitebin variable, but is filename expanded at +configuration time, for use in your makefiles. + +=item C<sitehtml1dir> + +From F<sitehtml1dir.U>: + +This variable contains the name of the directory in which site-specific +html source pages are to be put. It is the responsibility of the +F<Makefile.SH> to get the value of this into the proper command. +You must be prepared to do the F<~name> expansion yourself. +The standard distribution will put nothing in this directory. +After perl has been installed, users may install their own local +html pages in this directory with +MakeMaker F<Makefile.PL> +or equivalent. See C<INSTALL> for details. + +=item C<sitehtml1direxp> + +From F<sitehtml1dir.U>: + +This variable is the same as the sitehtml1dir variable, but is filename +expanded at configuration time, for convenient use in makefiles. + +=item C<sitehtml3dir> + +From F<sitehtml3dir.U>: + +This variable contains the name of the directory in which site-specific +library html source pages are to be put. It is the responsibility of the +F<Makefile.SH> to get the value of this into the proper command. +You must be prepared to do the F<~name> expansion yourself. +The standard distribution will put nothing in this directory. +After perl has been installed, users may install their own local +library html pages in this directory with +MakeMaker F<Makefile.PL> +or equivalent. See C<INSTALL> for details. + +=item C<sitehtml3direxp> + +From F<sitehtml3dir.U>: + +This variable is the same as the sitehtml3dir variable, but is filename +expanded at configuration time, for convenient use in makefiles. + +=item C<sitelib> + +From F<sitelib.U>: + +This variable contains the eventual value of the C<SITELIB> symbol, +which is the name of the private library for this package. It may +have a F<~> on the front. It is up to the makefile to eventually create +this directory while performing installation (with F<~> substitution). +The standard distribution will put nothing in this directory. +After perl has been installed, users may install their own local +architecture-independent modules in this directory with +MakeMaker F<Makefile.PL> +or equivalent. See C<INSTALL> for details. + +=item C<sitelib_stem> + +From F<sitelib.U>: + +This variable is $sitelibexp with any trailing version-specific component +removed. The elements in inc_version_list (F<inc_version_list.U>) can +be tacked onto this variable to generate a list of directories to search. + +=item C<sitelibexp> + +From F<sitelib.U>: + +This variable is the F<~name> expanded version of sitelib, so that you +may use it directly in Makefiles or shell scripts. + +=item C<siteman1dir> + +From F<siteman1dir.U>: + +This variable contains the name of the directory in which site-specific +manual source pages are to be put. It is the responsibility of the +F<Makefile.SH> to get the value of this into the proper command. +You must be prepared to do the F<~name> expansion yourself. +The standard distribution will put nothing in this directory. +After perl has been installed, users may install their own local +man1 pages in this directory with +MakeMaker F<Makefile.PL> +or equivalent. See C<INSTALL> for details. + +=item C<siteman1direxp> + +From F<siteman1dir.U>: + +This variable is the same as the siteman1dir variable, but is filename +expanded at configuration time, for convenient use in makefiles. + +=item C<siteman3dir> + +From F<siteman3dir.U>: + +This variable contains the name of the directory in which site-specific +library man source pages are to be put. It is the responsibility of the +F<Makefile.SH> to get the value of this into the proper command. +You must be prepared to do the F<~name> expansion yourself. +The standard distribution will put nothing in this directory. +After perl has been installed, users may install their own local +man3 pages in this directory with +MakeMaker F<Makefile.PL> +or equivalent. See C<INSTALL> for details. + +=item C<siteman3direxp> + +From F<siteman3dir.U>: + +This variable is the same as the siteman3dir variable, but is filename +expanded at configuration time, for convenient use in makefiles. + +=item C<siteprefix> + +From F<siteprefix.U>: + +This variable holds the full absolute path of the directory below +which the user will install add-on packages. +See C<INSTALL> for usage and examples. + +=item C<siteprefixexp> + +From F<siteprefix.U>: + +This variable holds the full absolute path of the directory below +which the user will install add-on packages. Derived from siteprefix. + +=item C<sitescript> + +From F<sitescript.U>: + +This variable holds the name of the directory in which the user wants +to put add-on publicly executable files for the package in question. It +is most often a local directory such as F</usr/local/bin>. Programs using +this variable must be prepared to deal with F<~name> substitution. +The standard distribution will put nothing in this directory. +After perl has been installed, users may install their own local +scripts in this directory with +MakeMaker F<Makefile.PL> +or equivalent. See C<INSTALL> for details. + +=item C<sitescriptexp> + +From F<sitescript.U>: + +This is the same as the sitescript variable, but is filename expanded at +configuration time, for use in your makefiles. + +=item C<sizesize> + +From F<sizesize.U>: + +This variable contains the size of a sizetype in bytes. + +=item C<sizetype> + +From F<sizetype.U>: + +This variable defines sizetype to be something like size_t, +unsigned long, or whatever type is used to declare length +parameters for string functions. + +=item C<sleep> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<sLOCALTIME_max> + +From F<time_size.U>: + +This variable defines the maximum value of the time_t offset that +the system function localtime () accepts + +=item C<sLOCALTIME_min> + +From F<time_size.U>: + +This variable defines the minimum value of the time_t offset that +the system function localtime () accepts + +=item C<smail> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<so> + +From F<so.U>: + +This variable holds the extension used to identify shared libraries +(also known as shared objects) on the system. Usually set to C<so>. + +=item C<sockethdr> + +From F<d_socket.U>: + +This variable has any cpp C<-I> flags needed for socket support. + +=item C<socketlib> + +From F<d_socket.U>: + +This variable has the names of any libraries needed for socket support. + +=item C<socksizetype> + +From F<socksizetype.U>: + +This variable holds the type used for the size argument +for various socket calls like accept. Usual values include +socklen_t, size_t, and int. + +=item C<sort> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the sort program. After Configure runs, +the value is reset to a plain C<sort> and is not useful. + +=item C<spackage> + +From F<package.U>: + +This variable contains the name of the package being constructed, +with the first letter uppercased, F<i.e>. suitable for starting +sentences. + +=item C<spitshell> + +From F<spitshell.U>: + +This variable contains the command necessary to spit out a runnable +shell on this system. It is either cat or a grep C<-v> for # comments. + +=item C<sPRId64> + +From F<quadfio.U>: + +This variable, if defined, contains the string used by stdio to +format 64-bit decimal numbers (format C<d>) for output. + +=item C<sPRIeldbl> + +From F<longdblfio.U>: + +This variable, if defined, contains the string used by stdio to +format long doubles (format C<e>) for output. + +=item C<sPRIEUldbl> + +From F<longdblfio.U>: + +This variable, if defined, contains the string used by stdio to +format long doubles (format C<E>) for output. +The C<U> in the name is to separate this from sPRIeldbl so that even +case-blind systems can see the difference. + +=item C<sPRIfldbl> + +From F<longdblfio.U>: + +This variable, if defined, contains the string used by stdio to +format long doubles (format C<f>) for output. + +=item C<sPRIFUldbl> + +From F<longdblfio.U>: + +This variable, if defined, contains the string used by stdio to +format long doubles (format C<F>) for output. +The C<U> in the name is to separate this from sPRIfldbl so that even +case-blind systems can see the difference. + +=item C<sPRIgldbl> + +From F<longdblfio.U>: + +This variable, if defined, contains the string used by stdio to +format long doubles (format C<g>) for output. + +=item C<sPRIGUldbl> + +From F<longdblfio.U>: + +This variable, if defined, contains the string used by stdio to +format long doubles (format C<G>) for output. +The C<U> in the name is to separate this from sPRIgldbl so that even +case-blind systems can see the difference. + +=item C<sPRIi64> + +From F<quadfio.U>: + +This variable, if defined, contains the string used by stdio to +format 64-bit decimal numbers (format C<i>) for output. + +=item C<sPRIo64> + +From F<quadfio.U>: + +This variable, if defined, contains the string used by stdio to +format 64-bit octal numbers (format C<o>) for output. + +=item C<sPRIu64> + +From F<quadfio.U>: + +This variable, if defined, contains the string used by stdio to +format 64-bit unsigned decimal numbers (format C<u>) for output. + +=item C<sPRIx64> + +From F<quadfio.U>: + +This variable, if defined, contains the string used by stdio to +format 64-bit hexadecimal numbers (format C<x>) for output. + +=item C<sPRIXU64> + +From F<quadfio.U>: + +This variable, if defined, contains the string used by stdio to +format 64-bit hExADECimAl numbers (format C<X>) for output. +The C<U> in the name is to separate this from sPRIx64 so that even +case-blind systems can see the difference. + +=item C<srand48_r_proto> + +From F<d_srand48_r.U>: + +This variable encodes the prototype of srand48_r. +It is zero if d_srand48_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_srand48_r +is defined. + +=item C<srandom_r_proto> + +From F<d_srandom_r.U>: + +This variable encodes the prototype of srandom_r. +It is zero if d_srandom_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_srandom_r +is defined. + +=item C<src> + +From F<src.U>: + +This variable holds the (possibly relative) path of the package source. +It is up to the Makefile to use this variable and set C<VPATH> accordingly +to find the sources remotely. Use $pkgsrc to have an absolute path. + +=item C<sSCNfldbl> + +From F<longdblfio.U>: + +This variable, if defined, contains the string used by stdio to +format long doubles (format C<f>) for input. + +=item C<ssizetype> + +From F<ssizetype.U>: + +This variable defines ssizetype to be something like ssize_t, +long or int. It is used by functions that return a count +of bytes or an error condition. It must be a signed type. +We will pick a type such that sizeof(SSize_t) == sizeof(Size_t). + +=item C<st_ino_sign> + +From F<st_ino_def.U>: + +This variable contains the signedness of struct stat's st_ino. +1 for unsigned, -1 for signed. + +=item C<st_ino_size> + +From F<st_ino_def.U>: + +This variable contains the size of struct stat's st_ino in bytes. + +=item C<startperl> + +From F<startperl.U>: + +This variable contains the string to put on the front of a perl +script to make sure (hopefully) that it runs with perl and not some +shell. Of course, that leading line must be followed by the classical +perl idiom: +eval 'exec perl -S $0 ${1+C<$@>}' +if $running_under_some_shell; +to guarantee perl startup should the shell execute the script. Note +that this magic incantation is not understood by csh. + +=item C<startsh> + +From F<startsh.U>: + +This variable contains the string to put on the front of a shell +script to make sure (hopefully) that it runs with sh and not some +other shell. + +=item C<static_ext> + +From F<Extensions.U>: + +This variable holds a list of C<XS> extension files we want to +link statically into the package. It is used by Makefile. + +=item C<stdchar> + +From F<stdchar.U>: + +This variable conditionally defines C<STDCHAR> to be the type of char +used in F<stdio.h>. It has the values "unsigned char" or C<char>. + +=item C<stdio_base> + +From F<d_stdstdio.U>: + +This variable defines how, given a C<FILE> pointer, fp, to access the +_base field (or equivalent) of F<stdio.h>'s C<FILE> structure. This will +be used to define the macro FILE_base(fp). + +=item C<stdio_bufsiz> + +From F<d_stdstdio.U>: + +This variable defines how, given a C<FILE> pointer, fp, to determine +the number of bytes store in the I/O buffer pointer to by the +_base field (or equivalent) of F<stdio.h>'s C<FILE> structure. This will +be used to define the macro FILE_bufsiz(fp). + +=item C<stdio_cnt> + +From F<d_stdstdio.U>: + +This variable defines how, given a C<FILE> pointer, fp, to access the +_cnt field (or equivalent) of F<stdio.h>'s C<FILE> structure. This will +be used to define the macro FILE_cnt(fp). + +=item C<stdio_filbuf> + +From F<d_stdstdio.U>: + +This variable defines how, given a C<FILE> pointer, fp, to tell +stdio to refill its internal buffers (?). This will +be used to define the macro FILE_filbuf(fp). + +=item C<stdio_ptr> + +From F<d_stdstdio.U>: + +This variable defines how, given a C<FILE> pointer, fp, to access the +_ptr field (or equivalent) of F<stdio.h>'s C<FILE> structure. This will +be used to define the macro FILE_ptr(fp). + +=item C<stdio_stream_array> + +From F<stdio_streams.U>: + +This variable tells the name of the array holding the stdio streams. +Usual values include _iob, __iob, and __sF. + +=item C<strerror_r_proto> + +From F<d_strerror_r.U>: + +This variable encodes the prototype of strerror_r. +It is zero if d_strerror_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_strerror_r +is defined. + +=item C<submit> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<subversion> + +From F<patchlevel.U>: + +The subversion level of this package. +The value of subversion comes from the F<patchlevel.h> file. +In a version number such as 5.6.1, this is the C<1>. +In F<patchlevel.h>, this is referred to as C<PERL_SUBVERSION>. +This is unique to perl. + +=item C<sysman> + +From F<sysman.U>: + +This variable holds the place where the manual is located on this +system. It is not the place where the user wants to put his manual +pages. Rather it is the place where Configure may look to find manual +for unix commands (section 1 of the manual usually). See mansrc. + +=item C<sysroot> + +From F<Sysroot.U>: + +This variable is empty unless supplied by the Configure user. +It can contain a path to an alternative root directory, under which +headers and libraries for the compilation target can be found. This +is generally used when cross-compiling using a gcc-like compiler. + +=back + +=head2 t + +=over 4 + +=item C<tail> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<tar> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<targetarch> + +From F<Cross.U>: + +If cross-compiling, this variable contains the target architecture. +If not, this will be empty. + +=item C<targetdir> + +From F<Cross.U>: + +This variable contains a path that will be created on the target +host using targetmkdir, and then used to copy the cross-compiled +executables to. Defaults to F</tmp> if not set. + +=item C<targetenv> + +From F<Cross.U>: + +If cross-compiling, this variable can be used to modify the +environment on the target system. +However, how and where it's used, and even if it's used at all, is +entirely dependent on both the transport mechanism (targetrun) and +what the target system is. Unless the relevant documentation says +otherwise, it is genereally not useful. + +=item C<targethost> + +From F<Cross.U>: + +This variable contains the name of a separate host machine that +can be used to run compiled test programs and perl tests on. +Set to empty string if not in use. + +=item C<targetmkdir> + +From F<Cross.U>: + +This variable contains the command used by Configure to create a +new directory on the target host. + +=item C<targetport> + +From F<Cross.U>: + +This variable contains the number of a network port to be used to +connect to the host in targethost, if unset defaults to 22 for ssh. + +=item C<targetsh> + +From F<sh.U>: + +If cross-compiling, this variable contains the location of sh on the +target system. +If not, this will be the same as $sh. + +=item C<tbl> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<tee> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<test> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the test program. After Configure runs, +the value is reset to a plain C<test> and is not useful. + +=item C<timeincl> + +From F<i_time.U>: + +This variable holds the full path of the included time header(s). + +=item C<timetype> + +From F<d_time.U>: + +This variable holds the type returned by time(). It can be long, +or time_t on C<BSD> sites (in which case <sys/types.h> should be +included). Anyway, the type Time_t should be used. + +=item C<tmpnam_r_proto> + +From F<d_tmpnam_r.U>: + +This variable encodes the prototype of tmpnam_r. +It is zero if d_tmpnam_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_tmpnam_r +is defined. + +=item C<to> + +From F<Cross.U>: + +This variable contains the command used by Configure +to copy to from the target host. Useful and available +only during Perl build. +The string C<:> if not cross-compiling. + +=item C<touch> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the touch program. After Configure runs, +the value is reset to a plain C<touch> and is not useful. + +=item C<tr> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the tr program. After Configure runs, +the value is reset to a plain C<tr> and is not useful. + +=item C<trnl> + +From F<trnl.U>: + +This variable contains the value to be passed to the tr(1) +command to transliterate a newline. Typical values are +C<\012> and C<\n>. This is needed for C<EBCDIC> systems where +newline is not necessarily C<\012>. + +=item C<troff> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<ttyname_r_proto> + +From F<d_ttyname_r.U>: + +This variable encodes the prototype of ttyname_r. +It is zero if d_ttyname_r is undef, and one of the +C<REENTRANT_PROTO_T_ABC> macros of F<reentr.h> if d_ttyname_r +is defined. + +=back + +=head2 u + +=over 4 + +=item C<u16size> + +From F<perlxv.U>: + +This variable is the size of an U16 in bytes. + +=item C<u16type> + +From F<perlxv.U>: + +This variable contains the C type used for Perl's U16. + +=item C<u32size> + +From F<perlxv.U>: + +This variable is the size of an U32 in bytes. + +=item C<u32type> + +From F<perlxv.U>: + +This variable contains the C type used for Perl's U32. + +=item C<u64size> + +From F<perlxv.U>: + +This variable is the size of an U64 in bytes. + +=item C<u64type> + +From F<perlxv.U>: + +This variable contains the C type used for Perl's U64. + +=item C<u8size> + +From F<perlxv.U>: + +This variable is the size of an U8 in bytes. + +=item C<u8type> + +From F<perlxv.U>: + +This variable contains the C type used for Perl's U8. + +=item C<uidformat> + +From F<uidf.U>: + +This variable contains the format string used for printing a Uid_t. + +=item C<uidsign> + +From F<uidsign.U>: + +This variable contains the signedness of a uidtype. +1 for unsigned, -1 for signed. + +=item C<uidsize> + +From F<uidsize.U>: + +This variable contains the size of a uidtype in bytes. + +=item C<uidtype> + +From F<uidtype.U>: + +This variable defines Uid_t to be something like uid_t, int, +ushort, or whatever type is used to declare user ids in the kernel. + +=item C<uname> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the uname program. After Configure runs, +the value is reset to a plain C<uname> and is not useful. + +=item C<uniq> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the uniq program. After Configure runs, +the value is reset to a plain C<uniq> and is not useful. + +=item C<uquadtype> + +From F<quadtype.U>: + +This variable defines Uquad_t to be something like unsigned long, +unsigned int, unsigned long long, uint64_t, or whatever type is +used for 64-bit integers. + +=item C<use64bitall> + +From F<use64bits.U>: + +This variable conditionally defines the USE_64_BIT_ALL symbol, +and indicates that 64-bit integer types should be used +when available. The maximal possible +64-bitness is employed: LP64 or ILP64, meaning that you will +be able to use more than 2 gigabytes of memory. This mode is +even more binary incompatible than USE_64_BIT_INT. You may not +be able to run the resulting executable in a 32-bit C<CPU> at all or +you may need at least to reboot your C<OS> to 64-bit mode. + +=item C<use64bitint> + +From F<use64bits.U>: + +This variable conditionally defines the USE_64_BIT_INT symbol, +and indicates that 64-bit integer types should be used +when available. The minimal possible 64-bitness +is employed, just enough to get 64-bit integers into Perl. +This may mean using for example "long longs", while your memory +may still be limited to 2 gigabytes. + +=item C<usecbacktrace> + +From F<usebacktrace.U>: + +This variable indicates whether we are compiling with backtrace +support. + +=item C<usecrosscompile> + +From F<Cross.U>: + +This variable conditionally defines the C<USE_CROSS_COMPILE> symbol, +and indicates that Perl has been cross-compiled. + +=item C<usedefaultstrict> + +From F<usedefaultstrict.U>: + +This setting provides a mechanism for perl developers to enable +strict by default. These defaults do not apply when perl is run +via -e or -E. + +=item C<usedevel> + +From F<Devel.U>: + +This variable indicates that Perl was configured with development +features enabled. This should not be done for production builds. + +=item C<usedl> + +From F<dlsrc.U>: + +This variable indicates if the system supports dynamic +loading of some sort. See also dlsrc and dlobj. + +=item C<usedtrace> + +From F<usedtrace.U>: + +This variable indicates whether we are compiling with dtrace +support. See also dtrace. + +=item C<usefaststdio> + +From F<usefaststdio.U>: + +This variable conditionally defines the C<USE_FAST_STDIO> symbol, +and indicates that Perl should be built to use C<fast stdio>. +Defaults to define in Perls 5.8 and earlier, to undef later. + +=item C<useithreads> + +From F<usethreads.U>: + +This variable conditionally defines the C<USE_ITHREADS> symbol, +and indicates that Perl should be built to use the interpreter-based +threading implementation. + +=item C<usekernprocpathname> + +From F<usekernprocpathname.U>: + +This variable, indicates that we can use sysctl with +C<KERN_PROC_PATHNAME> to get a full path for the executable, and hence +convert $^X to an absolute path. + +=item C<uselanginfo> + +From F<Extensions.U>: + +This variable holds either C<true> or C<false> to indicate +whether the I18N::Langinfo extension should be used. The sole +use for this currently is to allow an easy mechanism for users to skip +this extension from the Configure command line. + +=item C<uselargefiles> + +From F<uselfs.U>: + +This variable conditionally defines the C<USE_LARGE_FILES> symbol, +and indicates that large file interfaces should be used when +available. + +=item C<uselongdouble> + +From F<uselongdbl.U>: + +This variable conditionally defines the C<USE_LONG_DOUBLE> symbol, +and indicates that long doubles should be used when available. + +=item C<usemallocwrap> + +From F<mallocsrc.U>: + +This variable contains y if we are wrapping malloc to prevent +integer overflow during size calculations. + +=item C<usemorebits> + +From F<usemorebits.U>: + +This variable conditionally defines the C<USE_MORE_BITS> symbol, +and indicates that explicit 64-bit interfaces and long doubles +should be used when available. + +=item C<usemultiplicity> + +From F<usemultiplicity.U>: + +This variable conditionally defines the C<MULTIPLICITY> symbol, +and indicates that Perl should be built to use multiplicity. + +=item C<usemymalloc> + +From F<mallocsrc.U>: + +This variable contains y if the malloc that comes with this package +is desired over the system's version of malloc. People often include +special versions of malloc for efficiency, but such versions are often +less portable. See also mallocsrc and mallocobj. +If this is C<y>, then -lmalloc is removed from $libs. + +=item C<usenm> + +From F<usenm.U>: + +This variable contains C<true> or C<false> depending whether the +nm extraction is wanted or not. + +=item C<usensgetexecutablepath> + +From F<usensgetexecutablepath.U>: + +This symbol, if defined, indicates that we can use _NSGetExecutablePath +and realpath to get a full path for the executable, and hence convert +$^X to an absolute path. + +=item C<useopcode> + +From F<Extensions.U>: + +This variable holds either C<true> or C<false> to indicate +whether the Opcode extension should be used. The sole +use for this currently is to allow an easy mechanism +for users to skip the Opcode extension from the Configure +command line. + +=item C<useperlio> + +From F<useperlio.U>: + +This variable conditionally defines the C<USE_PERLIO> symbol, +and indicates that the PerlIO abstraction should be +used throughout. + +=item C<useposix> + +From F<Extensions.U>: + +This variable holds either C<true> or C<false> to indicate +whether the C<POSIX> extension should be used. The sole +use for this currently is to allow an easy mechanism +for hints files to indicate that C<POSIX> will not compile +on a particular system. + +=item C<usequadmath> + +From F<usequadmath.U>: + +This variable conditionally defines the C<USE_QUADMATH> symbol, +and indicates that the quadmath library __float128 long doubles +should be used when available. + +=item C<usereentrant> + +From F<usethreads.U>: + +This variable conditionally defines the C<USE_REENTRANT_API> symbol, +which indicates that the thread code may try to use the various +_r versions of library functions. This is only potentially +meaningful if usethreads is set and is very experimental, it is +not even prompted for. + +=item C<userelocatableinc> + +From F<bin.U>: + +This variable is set to true to indicate that perl should relocate +@C<INC> entries at runtime based on the path to the perl binary. +Any @C<INC> paths starting F<.../> are relocated relative to the directory +containing the perl binary, and a logical cleanup of the path is then +made around the join point (removing F<dir/../> pairs) + +=item C<useshrplib> + +From F<libperl.U>: + +This variable is set to C<true> if the user wishes +to build a shared libperl, and C<false> otherwise. + +=item C<usesitecustomize> + +From F<d_sitecustomize.U>: + +This variable is set to true when the user requires a mechanism that +allows the sysadmin to add entries to @C<INC> at runtime. This variable +being set, makes perl run F<$sitelib/sitecustomize.pl> at startup. + +=item C<usesocks> + +From F<usesocks.U>: + +This variable conditionally defines the C<USE_SOCKS> symbol, +and indicates that Perl should be built to use C<SOCKS>. + +=item C<usethreads> + +From F<usethreads.U>: + +This variable conditionally defines the C<USE_THREADS> symbol, +and indicates that Perl should be built to use threads. + +=item C<usevendorprefix> + +From F<vendorprefix.U>: + +This variable tells whether the vendorprefix +and consequently other vendor* paths are in use. + +=item C<useversionedarchname> + +From F<archname.U>: + +This variable indicates whether to include the $api_versionstring +as a component of the $archname. + +=item C<usevfork> + +From F<d_vfork.U>: + +This variable is set to true when the user accepts to use vfork. +It is set to false when no vfork is available or when the user +explicitly requests not to use vfork. + +=item C<usrinc> + +From F<usrinc.U>: + +This variable holds the path of the include files, which is +usually F</usr/include>. It is mainly used by other Configure units. + +=item C<uuname> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<uvoformat> + +From F<perlxvf.U>: + +This variable contains the format string used for printing +a Perl C<UV> as an unsigned octal integer. + +=item C<uvsize> + +From F<perlxv.U>: + +This variable is the size of a C<UV> in bytes. + +=item C<uvtype> + +From F<perlxv.U>: + +This variable contains the C type used for Perl's C<UV>. + +=item C<uvuformat> + +From F<perlxvf.U>: + +This variable contains the format string used for printing +a Perl C<UV> as an unsigned decimal integer. + +=item C<uvxformat> + +From F<perlxvf.U>: + +This variable contains the format string used for printing +a Perl C<UV> as an unsigned hexadecimal integer in lowercase abcdef. + +=item C<uvXUformat> + +From F<perlxvf.U>: + +This variable contains the format string used for printing +a Perl C<UV> as an unsigned hexadecimal integer in uppercase C<ABCDEF>. + +=back + +=head2 v + +=over 4 + +=item C<vendorarch> + +From F<vendorarch.U>: + +This variable contains the value of the C<PERL_VENDORARCH> symbol. +It may have a F<~> on the front. +The standard distribution will put nothing in this directory. +Vendors who distribute perl may wish to place their own +architecture-dependent modules and extensions in this directory with +MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor +or equivalent. See C<INSTALL> for details. + +=item C<vendorarchexp> + +From F<vendorarch.U>: + +This variable is the F<~name> expanded version of vendorarch, so that you +may use it directly in Makefiles or shell scripts. + +=item C<vendorbin> + +From F<vendorbin.U>: + +This variable contains the eventual value of the C<VENDORBIN> symbol. +It may have a F<~> on the front. +The standard distribution will put nothing in this directory. +Vendors who distribute perl may wish to place additional +binaries in this directory with +MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor +or equivalent. See C<INSTALL> for details. + +=item C<vendorbinexp> + +From F<vendorbin.U>: + +This variable is the F<~name> expanded version of vendorbin, so that you +may use it directly in Makefiles or shell scripts. + +=item C<vendorhtml1dir> + +From F<vendorhtml1dir.U>: + +This variable contains the name of the directory for html +pages. It may have a F<~> on the front. +The standard distribution will put nothing in this directory. +Vendors who distribute perl may wish to place their own +html pages in this directory with +MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor +or equivalent. See C<INSTALL> for details. + +=item C<vendorhtml1direxp> + +From F<vendorhtml1dir.U>: + +This variable is the F<~name> expanded version of vendorhtml1dir, so that you +may use it directly in Makefiles or shell scripts. + +=item C<vendorhtml3dir> + +From F<vendorhtml3dir.U>: + +This variable contains the name of the directory for html +library pages. It may have a F<~> on the front. +The standard distribution will put nothing in this directory. +Vendors who distribute perl may wish to place their own +html pages for modules and extensions in this directory with +MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor +or equivalent. See C<INSTALL> for details. + +=item C<vendorhtml3direxp> + +From F<vendorhtml3dir.U>: + +This variable is the F<~name> expanded version of vendorhtml3dir, so that you +may use it directly in Makefiles or shell scripts. + +=item C<vendorlib> + +From F<vendorlib.U>: + +This variable contains the eventual value of the C<VENDORLIB> symbol, +which is the name of the private library for this package. +The standard distribution will put nothing in this directory. +Vendors who distribute perl may wish to place their own +modules in this directory with +MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor +or equivalent. See C<INSTALL> for details. + +=item C<vendorlib_stem> + +From F<vendorlib.U>: + +This variable is $vendorlibexp with any trailing version-specific component +removed. The elements in inc_version_list (F<inc_version_list.U>) can +be tacked onto this variable to generate a list of directories to search. + +=item C<vendorlibexp> + +From F<vendorlib.U>: + +This variable is the F<~name> expanded version of vendorlib, so that you +may use it directly in Makefiles or shell scripts. + +=item C<vendorman1dir> + +From F<vendorman1dir.U>: + +This variable contains the name of the directory for man1 +pages. It may have a F<~> on the front. +The standard distribution will put nothing in this directory. +Vendors who distribute perl may wish to place their own +man1 pages in this directory with +MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor +or equivalent. See C<INSTALL> for details. + +=item C<vendorman1direxp> + +From F<vendorman1dir.U>: + +This variable is the F<~name> expanded version of vendorman1dir, so that you +may use it directly in Makefiles or shell scripts. + +=item C<vendorman3dir> + +From F<vendorman3dir.U>: + +This variable contains the name of the directory for man3 +pages. It may have a F<~> on the front. +The standard distribution will put nothing in this directory. +Vendors who distribute perl may wish to place their own +man3 pages in this directory with +MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor +or equivalent. See C<INSTALL> for details. + +=item C<vendorman3direxp> + +From F<vendorman3dir.U>: + +This variable is the F<~name> expanded version of vendorman3dir, so that you +may use it directly in Makefiles or shell scripts. + +=item C<vendorprefix> + +From F<vendorprefix.U>: + +This variable holds the full absolute path of the directory below +which the vendor will install add-on packages. +See C<INSTALL> for usage and examples. + +=item C<vendorprefixexp> + +From F<vendorprefix.U>: + +This variable holds the full absolute path of the directory below +which the vendor will install add-on packages. Derived from vendorprefix. + +=item C<vendorscript> + +From F<vendorscript.U>: + +This variable contains the eventual value of the C<VENDORSCRIPT> symbol. +It may have a F<~> on the front. +The standard distribution will put nothing in this directory. +Vendors who distribute perl may wish to place additional +executable scripts in this directory with +MakeMaker F<Makefile.PL> C<INSTALLDIRS>=vendor +or equivalent. See C<INSTALL> for details. + +=item C<vendorscriptexp> + +From F<vendorscript.U>: + +This variable is the F<~name> expanded version of vendorscript, so that you +may use it directly in Makefiles or shell scripts. + +=item C<version> + +From F<patchlevel.U>: + +The full version number of this package, such as 5.6.1 (or 5_6_1). +This combines revision, patchlevel, and subversion to get the +full version number, including any possible subversions. +This is suitable for use as a directory name, and hence is +filesystem dependent. + +=item C<version_patchlevel_string> + +From F<patchlevel.U>: + +This is a string combining version, subversion and +perl_patchlevel (if perl_patchlevel is non-zero). +It is typically something like +'version 7 subversion 1' or +'version 7 subversion 1 patchlevel 11224' +It is computed here to avoid duplication of code in F<myconfig.SH> +and F<lib/Config.pm>. + +=item C<versiononly> + +From F<versiononly.U>: + +If set, this symbol indicates that only the version-specific +components of a perl installation should be installed. +This may be useful for making a test installation of a new +version without disturbing the existing installation. +Setting versiononly is equivalent to setting installperl's -v option. +In particular, the non-versioned scripts and programs such as +a2p, c2ph, h2xs, pod2*, and perldoc are not installed +(see C<INSTALL> for a more complete list). Nor are the man +pages installed. +Usually, this is undef. + +=item C<vi> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=back + +=head2 x + +=over 4 + +=item C<xlibpth> + +From F<libpth.U>: + +This variable holds extra path (space-separated) used to find +libraries on this platform, for example C<CPU>-specific libraries +(on multi-C<CPU> platforms) may be listed here. + +=back + +=head2 y + +=over 4 + +=item C<yacc> + +From F<yacc.U>: + +This variable holds the name of the compiler compiler we +want to use in the Makefile. It can be yacc, byacc, or bison -y. + +=item C<yaccflags> + +From F<yacc.U>: + +This variable contains any additional yacc flags desired by the +user. It is up to the Makefile to use this. + +=back + +=head2 z + +=over 4 + +=item C<zcat> + +From F<Loc.U>: + +This variable is defined but not used by Configure. +The value is the empty string and is not useful. + +=item C<zip> + +From F<Loc.U>: + +This variable is used internally by Configure to determine the +full pathname (if any) of the zip program. After Configure runs, +the value is reset to a plain C<zip> and is not useful. + + +=back + +=head1 GIT DATA + +Information on the git commit from which the current perl binary was compiled +can be found in the variable C<$Config::Git_Data>. The variable is a +structured string that looks something like this: + + git_commit_id='ea0c2dbd5f5ac6845ecc7ec6696415bf8e27bd52' + git_describe='GitLive-blead-1076-gea0c2db' + git_branch='smartmatch' + git_uncommitted_changes='' + git_commit_id_title='Commit id:' + git_commit_date='2009-05-09 17:47:31 +0200' + +Its format is not guaranteed not to change over time. + +=head1 NOTE + +This module contains a good example of how to use tie to implement a +cache and an example of how to make a tied variable readonly to those +outside of it. + +=cut + |