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+package File::Temp;
+
+=head1 NAME
+
+File::Temp - return name and handle of a temporary file safely
+
+=begin __INTERNALS
+
+=head1 PORTABILITY
+
+This module is designed to be portable across operating systems
+and it currently supports Unix, VMS, DOS, OS/2, Windows and
+Mac OS (Classic). When
+porting to a new OS there are generally three main issues
+that have to be solved:
+
+=over 4
+
+=item *
+
+Can the OS unlink an open file? If it can not then the
+C<_can_unlink_opened_file> method should be modified.
+
+=item *
+
+Are the return values from C<stat> reliable? By default all the
+return values from C<stat> are compared when unlinking a temporary
+file using the filename and the handle. Operating systems other than
+unix do not always have valid entries in all fields. If C<unlink0> fails
+then the C<stat> comparison should be modified accordingly.
+
+=item *
+
+Security. Systems that can not support a test for the sticky bit
+on a directory can not use the MEDIUM and HIGH security tests.
+The C<_can_do_level> method should be modified accordingly.
+
+=back
+
+=end __INTERNALS
+
+=head1 SYNOPSIS
+
+ use File::Temp qw/ tempfile tempdir /;
+
+ $dir = tempdir( CLEANUP => 1 );
+ ($fh, $filename) = tempfile( DIR => $dir );
+
+ ($fh, $filename) = tempfile( $template, DIR => $dir);
+ ($fh, $filename) = tempfile( $template, SUFFIX => '.dat');
+
+ $fh = tempfile();
+
+MkTemp family:
+
+ use File::Temp qw/ :mktemp /;
+
+ ($fh, $file) = mkstemp( "tmpfileXXXXX" );
+ ($fh, $file) = mkstemps( "tmpfileXXXXXX", $suffix);
+
+ $tmpdir = mkdtemp( $template );
+
+ $unopened_file = mktemp( $template );
+
+POSIX functions:
+
+ use File::Temp qw/ :POSIX /;
+
+ $file = tmpnam();
+ $fh = tmpfile();
+
+ ($fh, $file) = tmpnam();
+ ($fh, $file) = tmpfile();
+
+
+Compatibility functions:
+
+ $unopened_file = File::Temp::tempnam( $dir, $pfx );
+
+=begin later
+
+Objects (NOT YET IMPLEMENTED):
+
+ require File::Temp;
+
+ $fh = new File::Temp($template);
+ $fname = $fh->filename;
+
+=end later
+
+=head1 DESCRIPTION
+
+C<File::Temp> can be used to create and open temporary files in a safe way.
+The tempfile() function can be used to return the name and the open
+filehandle of a temporary file. The tempdir() function can
+be used to create a temporary directory.
+
+The security aspect of temporary file creation is emphasized such that
+a filehandle and filename are returned together. This helps guarantee
+that a race condition can not occur where the temporary file is
+created by another process between checking for the existence of the
+file and its opening. Additional security levels are provided to
+check, for example, that the sticky bit is set on world writable
+directories. See L<"safe_level"> for more information.
+
+For compatibility with popular C library functions, Perl implementations of
+the mkstemp() family of functions are provided. These are, mkstemp(),
+mkstemps(), mkdtemp() and mktemp().
+
+Additionally, implementations of the standard L<POSIX|POSIX>
+tmpnam() and tmpfile() functions are provided if required.
+
+Implementations of mktemp(), tmpnam(), and tempnam() are provided,
+but should be used with caution since they return only a filename
+that was valid when function was called, so cannot guarantee
+that the file will not exist by the time the caller opens the filename.
+
+=cut
+
+# 5.6.0 gives us S_IWOTH, S_IWGRP, our and auto-vivifying filehandls
+# People would like a version on 5.005 so give them what they want :-)
+use 5.005;
+use strict;
+use Carp;
+use File::Spec 0.8;
+use File::Path qw/ rmtree /;
+use Fcntl 1.03;
+use Errno;
+require VMS::Stdio if $^O eq 'VMS';
+
+# Need the Symbol package if we are running older perl
+require Symbol if $] < 5.006;
+
+
+# use 'our' on v5.6.0
+use vars qw($VERSION @EXPORT_OK %EXPORT_TAGS $DEBUG);
+
+$DEBUG = 0;
+
+# We are exporting functions
+
+use base qw/Exporter/;
+
+# Export list - to allow fine tuning of export table
+
+@EXPORT_OK = qw{
+ tempfile
+ tempdir
+ tmpnam
+ tmpfile
+ mktemp
+ mkstemp
+ mkstemps
+ mkdtemp
+ unlink0
+ };
+
+# Groups of functions for export
+
+%EXPORT_TAGS = (
+ 'POSIX' => [qw/ tmpnam tmpfile /],
+ 'mktemp' => [qw/ mktemp mkstemp mkstemps mkdtemp/],
+ );
+
+# add contents of these tags to @EXPORT
+Exporter::export_tags('POSIX','mktemp');
+
+# Version number
+
+$VERSION = '0.13';
+
+# This is a list of characters that can be used in random filenames
+
+my @CHARS = (qw/ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
+ a b c d e f g h i j k l m n o p q r s t u v w x y z
+ 0 1 2 3 4 5 6 7 8 9 _
+ /);
+
+# Maximum number of tries to make a temp file before failing
+
+use constant MAX_TRIES => 10;
+
+# Minimum number of X characters that should be in a template
+use constant MINX => 4;
+
+# Default template when no template supplied
+
+use constant TEMPXXX => 'X' x 10;
+
+# Constants for the security level
+
+use constant STANDARD => 0;
+use constant MEDIUM => 1;
+use constant HIGH => 2;
+
+# OPENFLAGS. If we defined the flag to use with Sysopen here this gives
+# us an optimisation when many temporary files are requested
+
+my $OPENFLAGS = O_CREAT | O_EXCL | O_RDWR;
+
+unless ($^O eq 'MacOS') {
+ for my $oflag (qw/ FOLLOW BINARY LARGEFILE EXLOCK NOINHERIT /) {
+ my ($bit, $func) = (0, "Fcntl::O_" . $oflag);
+ no strict 'refs';
+ $OPENFLAGS |= $bit if eval {
+ # Make sure that redefined die handlers do not cause problems
+ # eg CGI::Carp
+ local $SIG{__DIE__} = sub {};
+ local $SIG{__WARN__} = sub {};
+ $bit = &$func();
+ 1;
+ };
+ }
+}
+
+# On some systems the O_TEMPORARY flag can be used to tell the OS
+# to automatically remove the file when it is closed. This is fine
+# in most cases but not if tempfile is called with UNLINK=>0 and
+# the filename is requested -- in the case where the filename is to
+# be passed to another routine. This happens on windows. We overcome
+# this by using a second open flags variable
+
+my $OPENTEMPFLAGS = $OPENFLAGS;
+unless ($^O eq 'MacOS') {
+ for my $oflag (qw/ TEMPORARY /) {
+ my ($bit, $func) = (0, "Fcntl::O_" . $oflag);
+ no strict 'refs';
+ $OPENTEMPFLAGS |= $bit if eval {
+ # Make sure that redefined die handlers do not cause problems
+ # eg CGI::Carp
+ local $SIG{__DIE__} = sub {};
+ local $SIG{__WARN__} = sub {};
+ $bit = &$func();
+ 1;
+ };
+ }
+}
+
+# INTERNAL ROUTINES - not to be used outside of package
+
+# Generic routine for getting a temporary filename
+# modelled on OpenBSD _gettemp() in mktemp.c
+
+# The template must contain X's that are to be replaced
+# with the random values
+
+# Arguments:
+
+# TEMPLATE - string containing the XXXXX's that is converted
+# to a random filename and opened if required
+
+# Optionally, a hash can also be supplied containing specific options
+# "open" => if true open the temp file, else just return the name
+# default is 0
+# "mkdir"=> if true, we are creating a temp directory rather than tempfile
+# default is 0
+# "suffixlen" => number of characters at end of PATH to be ignored.
+# default is 0.
+# "unlink_on_close" => indicates that, if possible, the OS should remove
+# the file as soon as it is closed. Usually indicates
+# use of the O_TEMPORARY flag to sysopen.
+# Usually irrelevant on unix
+
+# Optionally a reference to a scalar can be passed into the function
+# On error this will be used to store the reason for the error
+# "ErrStr" => \$errstr
+
+# "open" and "mkdir" can not both be true
+# "unlink_on_close" is not used when "mkdir" is true.
+
+# The default options are equivalent to mktemp().
+
+# Returns:
+# filehandle - open file handle (if called with doopen=1, else undef)
+# temp name - name of the temp file or directory
+
+# For example:
+# ($fh, $name) = _gettemp($template, "open" => 1);
+
+# for the current version, failures are associated with
+# stored in an error string and returned to give the reason whilst debugging
+# This routine is not called by any external function
+sub _gettemp {
+
+ croak 'Usage: ($fh, $name) = _gettemp($template, OPTIONS);'
+ unless scalar(@_) >= 1;
+
+ # the internal error string - expect it to be overridden
+ # Need this in case the caller decides not to supply us a value
+ # need an anonymous scalar
+ my $tempErrStr;
+
+ # Default options
+ my %options = (
+ "open" => 0,
+ "mkdir" => 0,
+ "suffixlen" => 0,
+ "unlink_on_close" => 0,
+ "ErrStr" => \$tempErrStr,
+ );
+
+ # Read the template
+ my $template = shift;
+ if (ref($template)) {
+ # Use a warning here since we have not yet merged ErrStr
+ carp "File::Temp::_gettemp: template must not be a reference";
+ return ();
+ }
+
+ # Check that the number of entries on stack are even
+ if (scalar(@_) % 2 != 0) {
+ # Use a warning here since we have not yet merged ErrStr
+ carp "File::Temp::_gettemp: Must have even number of options";
+ return ();
+ }
+
+ # Read the options and merge with defaults
+ %options = (%options, @_) if @_;
+
+ # Make sure the error string is set to undef
+ ${$options{ErrStr}} = undef;
+
+ # Can not open the file and make a directory in a single call
+ if ($options{"open"} && $options{"mkdir"}) {
+ ${$options{ErrStr}} = "doopen and domkdir can not both be true\n";
+ return ();
+ }
+
+ # Find the start of the end of the Xs (position of last X)
+ # Substr starts from 0
+ my $start = length($template) - 1 - $options{"suffixlen"};
+
+ # Check that we have at least MINX x X (eg 'XXXX") at the end of the string
+ # (taking suffixlen into account). Any fewer is insecure.
+
+ # Do it using substr - no reason to use a pattern match since
+ # we know where we are looking and what we are looking for
+
+ if (substr($template, $start - MINX + 1, MINX) ne 'X' x MINX) {
+ ${$options{ErrStr}} = "The template must contain at least ".
+ MINX . " 'X' characters\n";
+ return ();
+ }
+
+ # Replace all the X at the end of the substring with a
+ # random character or just all the XX at the end of a full string.
+ # Do it as an if, since the suffix adjusts which section to replace
+ # and suffixlen=0 returns nothing if used in the substr directly
+ # and generate a full path from the template
+
+ my $path = _replace_XX($template, $options{"suffixlen"});
+
+
+ # Split the path into constituent parts - eventually we need to check
+ # whether the directory exists
+ # We need to know whether we are making a temp directory
+ # or a tempfile
+
+ my ($volume, $directories, $file);
+ my $parent; # parent directory
+ if ($options{"mkdir"}) {
+ # There is no filename at the end
+ ($volume, $directories, $file) = File::Spec->splitpath( $path, 1);
+
+ # The parent is then $directories without the last directory
+ # Split the directory and put it back together again
+ my @dirs = File::Spec->splitdir($directories);
+
+ # If @dirs only has one entry (i.e. the directory template) that means
+ # we are in the current directory
+ if ($#dirs == 0) {
+ $parent = File::Spec->curdir;
+ } else {
+
+ if ($^O eq 'VMS') { # need volume to avoid relative dir spec
+ $parent = File::Spec->catdir($volume, @dirs[0..$#dirs-1]);
+ $parent = 'sys$disk:[]' if $parent eq '';
+ } else {
+
+ # Put it back together without the last one
+ $parent = File::Spec->catdir(@dirs[0..$#dirs-1]);
+
+ # ...and attach the volume (no filename)
+ $parent = File::Spec->catpath($volume, $parent, '');
+ }
+
+ }
+
+ } else {
+
+ # Get rid of the last filename (use File::Basename for this?)
+ ($volume, $directories, $file) = File::Spec->splitpath( $path );
+
+ # Join up without the file part
+ $parent = File::Spec->catpath($volume,$directories,'');
+
+ # If $parent is empty replace with curdir
+ $parent = File::Spec->curdir
+ unless $directories ne '';
+
+ }
+
+ # Check that the parent directories exist
+ # Do this even for the case where we are simply returning a name
+ # not a file -- no point returning a name that includes a directory
+ # that does not exist or is not writable
+
+ unless (-d $parent) {
+ ${$options{ErrStr}} = "Parent directory ($parent) is not a directory";
+ return ();
+ }
+ unless (-w _) {
+ ${$options{ErrStr}} = "Parent directory ($parent) is not writable\n";
+ return ();
+ }
+
+
+ # Check the stickiness of the directory and chown giveaway if required
+ # If the directory is world writable the sticky bit
+ # must be set
+
+ if (File::Temp->safe_level == MEDIUM) {
+ my $safeerr;
+ unless (_is_safe($parent,\$safeerr)) {
+ ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)";
+ return ();
+ }
+ } elsif (File::Temp->safe_level == HIGH) {
+ my $safeerr;
+ unless (_is_verysafe($parent, \$safeerr)) {
+ ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)";
+ return ();
+ }
+ }
+
+
+ # Now try MAX_TRIES time to open the file
+ for (my $i = 0; $i < MAX_TRIES; $i++) {
+
+ # Try to open the file if requested
+ if ($options{"open"}) {
+ my $fh;
+
+ # If we are running before perl5.6.0 we can not auto-vivify
+ if ($] < 5.006) {
+ $fh = &Symbol::gensym;
+ }
+
+ # Try to make sure this will be marked close-on-exec
+ # XXX: Win32 doesn't respect this, nor the proper fcntl,
+ # but may have O_NOINHERIT. This may or may not be in Fcntl.
+ local $^F = 2;
+
+ # Store callers umask
+ my $umask = umask();
+
+ # Set a known umask
+ umask(066);
+
+ # Attempt to open the file
+ my $open_success = undef;
+ if ( $^O eq 'VMS' and $options{"unlink_on_close"} ) {
+ # make it auto delete on close by setting FAB$V_DLT bit
+ $fh = VMS::Stdio::vmssysopen($path, $OPENFLAGS, 0600, 'fop=dlt');
+ $open_success = $fh;
+ } else {
+ my $flags = ( $options{"unlink_on_close"} ?
+ $OPENTEMPFLAGS :
+ $OPENFLAGS );
+ $open_success = sysopen($fh, $path, $flags, 0600);
+ }
+ if ( $open_success ) {
+
+ # Reset umask
+ umask($umask) if defined $umask;
+
+ # Opened successfully - return file handle and name
+ return ($fh, $path);
+
+ } else {
+ # Reset umask
+ umask($umask) if defined $umask;
+
+ # Error opening file - abort with error
+ # if the reason was anything but EEXIST
+ unless ($!{EEXIST}) {
+ ${$options{ErrStr}} = "Could not create temp file $path: $!";
+ return ();
+ }
+
+ # Loop round for another try
+
+ }
+ } elsif ($options{"mkdir"}) {
+
+ # Store callers umask
+ my $umask = umask();
+
+ # Set a known umask
+ umask(066);
+
+ # Open the temp directory
+ if (mkdir( $path, 0700)) {
+ # created okay
+ # Reset umask
+ umask($umask) if defined $umask;
+
+ return undef, $path;
+ } else {
+
+ # Reset umask
+ umask($umask) if defined $umask;
+
+ # Abort with error if the reason for failure was anything
+ # except EEXIST
+ unless ($!{EEXIST}) {
+ ${$options{ErrStr}} = "Could not create directory $path: $!";
+ return ();
+ }
+
+ # Loop round for another try
+
+ }
+
+ } else {
+
+ # Return true if the file can not be found
+ # Directory has been checked previously
+
+ return (undef, $path) unless -e $path;
+
+ # Try again until MAX_TRIES
+
+ }
+
+ # Did not successfully open the tempfile/dir
+ # so try again with a different set of random letters
+ # No point in trying to increment unless we have only
+ # 1 X say and the randomness could come up with the same
+ # file MAX_TRIES in a row.
+
+ # Store current attempt - in principal this implies that the
+ # 3rd time around the open attempt that the first temp file
+ # name could be generated again. Probably should store each
+ # attempt and make sure that none are repeated
+
+ my $original = $path;
+ my $counter = 0; # Stop infinite loop
+ my $MAX_GUESS = 50;
+
+ do {
+
+ # Generate new name from original template
+ $path = _replace_XX($template, $options{"suffixlen"});
+
+ $counter++;
+
+ } until ($path ne $original || $counter > $MAX_GUESS);
+
+ # Check for out of control looping
+ if ($counter > $MAX_GUESS) {
+ ${$options{ErrStr}} = "Tried to get a new temp name different to the previous value $MAX_GUESS times.\nSomething wrong with template?? ($template)";
+ return ();
+ }
+
+ }
+
+ # If we get here, we have run out of tries
+ ${ $options{ErrStr} } = "Have exceeded the maximum number of attempts ("
+ . MAX_TRIES . ") to open temp file/dir";
+
+ return ();
+
+}
+
+# Internal routine to return a random character from the
+# character list. Does not do an srand() since rand()
+# will do one automatically
+
+# No arguments. Return value is the random character
+
+# No longer called since _replace_XX runs a few percent faster if
+# I inline the code. This is important if we are creating thousands of
+# temporary files.
+
+sub _randchar {
+
+ $CHARS[ int( rand( $#CHARS ) ) ];
+
+}
+
+# Internal routine to replace the XXXX... with random characters
+# This has to be done by _gettemp() every time it fails to
+# open a temp file/dir
+
+# Arguments: $template (the template with XXX),
+# $ignore (number of characters at end to ignore)
+
+# Returns: modified template
+
+sub _replace_XX {
+
+ croak 'Usage: _replace_XX($template, $ignore)'
+ unless scalar(@_) == 2;
+
+ my ($path, $ignore) = @_;
+
+ # Do it as an if, since the suffix adjusts which section to replace
+ # and suffixlen=0 returns nothing if used in the substr directly
+ # Alternatively, could simply set $ignore to length($path)-1
+ # Don't want to always use substr when not required though.
+
+ if ($ignore) {
+ substr($path, 0, - $ignore) =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge;
+ } else {
+ $path =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge;
+ }
+
+ return $path;
+}
+
+# internal routine to check to see if the directory is safe
+# First checks to see if the directory is not owned by the
+# current user or root. Then checks to see if anyone else
+# can write to the directory and if so, checks to see if
+# it has the sticky bit set
+
+# Will not work on systems that do not support sticky bit
+
+#Args: directory path to check
+# Optionally: reference to scalar to contain error message
+# Returns true if the path is safe and false otherwise.
+# Returns undef if can not even run stat() on the path
+
+# This routine based on version written by Tom Christiansen
+
+# Presumably, by the time we actually attempt to create the
+# file or directory in this directory, it may not be safe
+# anymore... Have to run _is_safe directly after the open.
+
+sub _is_safe {
+
+ my $path = shift;
+ my $err_ref = shift;
+
+ # Stat path
+ my @info = stat($path);
+ unless (scalar(@info)) {
+ $$err_ref = "stat(path) returned no values";
+ return 0;
+ };
+ return 1 if $^O eq 'VMS'; # owner delete control at file level
+
+ # Check to see whether owner is neither superuser (or a system uid) nor me
+ # Use the real uid from the $< variable
+ # UID is in [4]
+ if ($info[4] > File::Temp->top_system_uid() && $info[4] != $<) {
+
+ Carp::cluck(sprintf "uid=$info[4] topuid=%s \$<=$< path='$path'",
+ File::Temp->top_system_uid());
+
+ $$err_ref = "Directory owned neither by root nor the current user"
+ if ref($err_ref);
+ return 0;
+ }
+
+ # check whether group or other can write file
+ # use 066 to detect either reading or writing
+ # use 022 to check writability
+ # Do it with S_IWOTH and S_IWGRP for portability (maybe)
+ # mode is in info[2]
+ if (($info[2] & &Fcntl::S_IWGRP) || # Is group writable?
+ ($info[2] & &Fcntl::S_IWOTH) ) { # Is world writable?
+ # Must be a directory
+ unless (-d _) {
+ $$err_ref = "Path ($path) is not a directory"
+ if ref($err_ref);
+ return 0;
+ }
+ # Must have sticky bit set
+ unless (-k _) {
+ $$err_ref = "Sticky bit not set on $path when dir is group|world writable"
+ if ref($err_ref);
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+# Internal routine to check whether a directory is safe
+# for temp files. Safer than _is_safe since it checks for
+# the possibility of chown giveaway and if that is a possibility
+# checks each directory in the path to see if it is safe (with _is_safe)
+
+# If _PC_CHOWN_RESTRICTED is not set, does the full test of each
+# directory anyway.
+
+# Takes optional second arg as scalar ref to error reason
+
+sub _is_verysafe {
+
+ # Need POSIX - but only want to bother if really necessary due to overhead
+ require POSIX;
+
+ my $path = shift;
+ print "_is_verysafe testing $path\n" if $DEBUG;
+ return 1 if $^O eq 'VMS'; # owner delete control at file level
+
+ my $err_ref = shift;
+
+ # Should Get the value of _PC_CHOWN_RESTRICTED if it is defined
+ # and If it is not there do the extensive test
+ my $chown_restricted;
+ $chown_restricted = &POSIX::_PC_CHOWN_RESTRICTED()
+ if eval { &POSIX::_PC_CHOWN_RESTRICTED(); 1};
+
+ # If chown_resticted is set to some value we should test it
+ if (defined $chown_restricted) {
+
+ # Return if the current directory is safe
+ return _is_safe($path,$err_ref) if POSIX::sysconf( $chown_restricted );
+
+ }
+
+ # To reach this point either, the _PC_CHOWN_RESTRICTED symbol
+ # was not avialable or the symbol was there but chown giveaway
+ # is allowed. Either way, we now have to test the entire tree for
+ # safety.
+
+ # Convert path to an absolute directory if required
+ unless (File::Spec->file_name_is_absolute($path)) {
+ $path = File::Spec->rel2abs($path);
+ }
+
+ # Split directory into components - assume no file
+ my ($volume, $directories, undef) = File::Spec->splitpath( $path, 1);
+
+ # Slightly less efficient than having a function in File::Spec
+ # to chop off the end of a directory or even a function that
+ # can handle ../ in a directory tree
+ # Sometimes splitdir() returns a blank at the end
+ # so we will probably check the bottom directory twice in some cases
+ my @dirs = File::Spec->splitdir($directories);
+
+ # Concatenate one less directory each time around
+ foreach my $pos (0.. $#dirs) {
+ # Get a directory name
+ my $dir = File::Spec->catpath($volume,
+ File::Spec->catdir(@dirs[0.. $#dirs - $pos]),
+ ''
+ );
+
+ print "TESTING DIR $dir\n" if $DEBUG;
+
+ # Check the directory
+ return 0 unless _is_safe($dir,$err_ref);
+
+ }
+
+ return 1;
+}
+
+
+
+# internal routine to determine whether unlink works on this
+# platform for files that are currently open.
+# Returns true if we can, false otherwise.
+
+# Currently WinNT, OS/2 and VMS can not unlink an opened file
+# On VMS this is because the O_EXCL flag is used to open the
+# temporary file. Currently I do not know enough about the issues
+# on VMS to decide whether O_EXCL is a requirement.
+
+sub _can_unlink_opened_file {
+
+ if ($^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'VMS' || $^O eq 'dos' || $^O eq 'MacOS') {
+ return 0;
+ } else {
+ return 1;
+ }
+
+}
+
+# internal routine to decide which security levels are allowed
+# see safe_level() for more information on this
+
+# Controls whether the supplied security level is allowed
+
+# $cando = _can_do_level( $level )
+
+sub _can_do_level {
+
+ # Get security level
+ my $level = shift;
+
+ # Always have to be able to do STANDARD
+ return 1 if $level == STANDARD;
+
+ # Currently, the systems that can do HIGH or MEDIUM are identical
+ if ( $^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'cygwin' || $^O eq 'dos' || $^O eq 'MacOS') {
+ return 0;
+ } else {
+ return 1;
+ }
+
+}
+
+# This routine sets up a deferred unlinking of a specified
+# filename and filehandle. It is used in the following cases:
+# - Called by unlink0 if an opened file can not be unlinked
+# - Called by tempfile() if files are to be removed on shutdown
+# - Called by tempdir() if directories are to be removed on shutdown
+
+# Arguments:
+# _deferred_unlink( $fh, $fname, $isdir );
+#
+# - filehandle (so that it can be expclicitly closed if open
+# - filename (the thing we want to remove)
+# - isdir (flag to indicate that we are being given a directory)
+# [and hence no filehandle]
+
+# Status is not referred to since all the magic is done with an END block
+
+{
+ # Will set up two lexical variables to contain all the files to be
+ # removed. One array for files, another for directories
+ # They will only exist in this block
+ # This means we only have to set up a single END block to remove all files
+ # @files_to_unlink contains an array ref with the filehandle and filename
+ my (@files_to_unlink, @dirs_to_unlink);
+
+ # Set up an end block to use these arrays
+ END {
+ # Files
+ foreach my $file (@files_to_unlink) {
+ # close the filehandle without checking its state
+ # in order to make real sure that this is closed
+ # if its already closed then I dont care about the answer
+ # probably a better way to do this
+ close($file->[0]); # file handle is [0]
+
+ if (-f $file->[1]) { # file name is [1]
+ unlink $file->[1] or warn "Error removing ".$file->[1];
+ }
+ }
+ # Dirs
+ foreach my $dir (@dirs_to_unlink) {
+ if (-d $dir) {
+ rmtree($dir, $DEBUG, 1);
+ }
+ }
+
+ }
+
+ # This is the sub called to register a file for deferred unlinking
+ # This could simply store the input parameters and defer everything
+ # until the END block. For now we do a bit of checking at this
+ # point in order to make sure that (1) we have a file/dir to delete
+ # and (2) we have been called with the correct arguments.
+ sub _deferred_unlink {
+
+ croak 'Usage: _deferred_unlink($fh, $fname, $isdir)'
+ unless scalar(@_) == 3;
+
+ my ($fh, $fname, $isdir) = @_;
+
+ warn "Setting up deferred removal of $fname\n"
+ if $DEBUG;
+
+ # If we have a directory, check that it is a directory
+ if ($isdir) {
+
+ if (-d $fname) {
+
+ # Directory exists so store it
+ # first on VMS turn []foo into [.foo] for rmtree
+ $fname = VMS::Filespec::vmspath($fname) if $^O eq 'VMS';
+ push (@dirs_to_unlink, $fname);
+
+ } else {
+ carp "Request to remove directory $fname could not be completed since it does not exist!\n" if $^W;
+ }
+
+ } else {
+
+ if (-f $fname) {
+
+ # file exists so store handle and name for later removal
+ push(@files_to_unlink, [$fh, $fname]);
+
+ } else {
+ carp "Request to remove file $fname could not be completed since it is not there!\n" if $^W;
+ }
+
+ }
+
+ }
+
+
+}
+
+=head1 FUNCTIONS
+
+This section describes the recommended interface for generating
+temporary files and directories.
+
+=over 4
+
+=item B<tempfile>
+
+This is the basic function to generate temporary files.
+The behaviour of the file can be changed using various options:
+
+ ($fh, $filename) = tempfile();
+
+Create a temporary file in the directory specified for temporary
+files, as specified by the tmpdir() function in L<File::Spec>.
+
+ ($fh, $filename) = tempfile($template);
+
+Create a temporary file in the current directory using the supplied
+template. Trailing `X' characters are replaced with random letters to
+generate the filename. At least four `X' characters must be present
+in the template.
+
+ ($fh, $filename) = tempfile($template, SUFFIX => $suffix)
+
+Same as previously, except that a suffix is added to the template
+after the `X' translation. Useful for ensuring that a temporary
+filename has a particular extension when needed by other applications.
+But see the WARNING at the end.
+
+ ($fh, $filename) = tempfile($template, DIR => $dir);
+
+Translates the template as before except that a directory name
+is specified.
+
+ ($fh, $filename) = tempfile($template, UNLINK => 1);
+
+Return the filename and filehandle as before except that the file is
+automatically removed when the program exits. Default is for the file
+to be removed if a file handle is requested and to be kept if the
+filename is requested. In a scalar context (where no filename is
+returned) the file is always deleted either on exit or when it is closed.
+
+If the template is not specified, a template is always
+automatically generated. This temporary file is placed in tmpdir()
+(L<File::Spec>) unless a directory is specified explicitly with the
+DIR option.
+
+ $fh = tempfile( $template, DIR => $dir );
+
+If called in scalar context, only the filehandle is returned
+and the file will automatically be deleted when closed (see
+the description of tmpfile() elsewhere in this document).
+This is the preferred mode of operation, as if you only
+have a filehandle, you can never create a race condition
+by fumbling with the filename. On systems that can not unlink
+an open file or can not mark a file as temporary when it is opened
+(for example, Windows NT uses the C<O_TEMPORARY> flag))
+the file is marked for deletion when the program ends (equivalent
+to setting UNLINK to 1). The C<UNLINK> flag is ignored if present.
+
+ (undef, $filename) = tempfile($template, OPEN => 0);
+
+This will return the filename based on the template but
+will not open this file. Cannot be used in conjunction with
+UNLINK set to true. Default is to always open the file
+to protect from possible race conditions. A warning is issued
+if warnings are turned on. Consider using the tmpnam()
+and mktemp() functions described elsewhere in this document
+if opening the file is not required.
+
+Options can be combined as required.
+
+=cut
+
+sub tempfile {
+
+ # Can not check for argument count since we can have any
+ # number of args
+
+ # Default options
+ my %options = (
+ "DIR" => undef, # Directory prefix
+ "SUFFIX" => '', # Template suffix
+ "UNLINK" => 0, # Do not unlink file on exit
+ "OPEN" => 1, # Open file
+ );
+
+ # Check to see whether we have an odd or even number of arguments
+ my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef);
+
+ # Read the options and merge with defaults
+ %options = (%options, @_) if @_;
+
+ # First decision is whether or not to open the file
+ if (! $options{"OPEN"}) {
+
+ warn "tempfile(): temporary filename requested but not opened.\nPossibly unsafe, consider using tempfile() with OPEN set to true\n"
+ if $^W;
+
+ }
+
+ if ($options{"DIR"} and $^O eq 'VMS') {
+
+ # on VMS turn []foo into [.foo] for concatenation
+ $options{"DIR"} = VMS::Filespec::vmspath($options{"DIR"});
+ }
+
+ # Construct the template
+
+ # Have a choice of trying to work around the mkstemp/mktemp/tmpnam etc
+ # functions or simply constructing a template and using _gettemp()
+ # explicitly. Go for the latter
+
+ # First generate a template if not defined and prefix the directory
+ # If no template must prefix the temp directory
+ if (defined $template) {
+ if ($options{"DIR"}) {
+
+ $template = File::Spec->catfile($options{"DIR"}, $template);
+
+ }
+
+ } else {
+
+ if ($options{"DIR"}) {
+
+ $template = File::Spec->catfile($options{"DIR"}, TEMPXXX);
+
+ } else {
+
+ $template = File::Spec->catfile(File::Spec->tmpdir, TEMPXXX);
+
+ }
+
+ }
+
+ # Now add a suffix
+ $template .= $options{"SUFFIX"};
+
+ # Determine whether we should tell _gettemp to unlink the file
+ # On unix this is irrelevant and can be worked out after the file is
+ # opened (simply by unlinking the open filehandle). On Windows or VMS
+ # we have to indicate temporary-ness when we open the file. In general
+ # we only want a true temporary file if we are returning just the
+ # filehandle - if the user wants the filename they probably do not
+ # want the file to disappear as soon as they close it.
+ # For this reason, tie unlink_on_close to the return context regardless
+ # of OS.
+ my $unlink_on_close = ( wantarray ? 0 : 1);
+
+ # Create the file
+ my ($fh, $path, $errstr);
+ croak "Error in tempfile() using $template: $errstr"
+ unless (($fh, $path) = _gettemp($template,
+ "open" => $options{'OPEN'},
+ "mkdir"=> 0 ,
+ "unlink_on_close" => $unlink_on_close,
+ "suffixlen" => length($options{'SUFFIX'}),
+ "ErrStr" => \$errstr,
+ ) );
+
+ # Set up an exit handler that can do whatever is right for the
+ # system. This removes files at exit when requested explicitly or when
+ # system is asked to unlink_on_close but is unable to do so because
+ # of OS limitations.
+ # The latter should be achieved by using a tied filehandle.
+ # Do not check return status since this is all done with END blocks.
+ _deferred_unlink($fh, $path, 0) if $options{"UNLINK"};
+
+ # Return
+ if (wantarray()) {
+
+ if ($options{'OPEN'}) {
+ return ($fh, $path);
+ } else {
+ return (undef, $path);
+ }
+
+ } else {
+
+ # Unlink the file. It is up to unlink0 to decide what to do with
+ # this (whether to unlink now or to defer until later)
+ unlink0($fh, $path) or croak "Error unlinking file $path using unlink0";
+
+ # Return just the filehandle.
+ return $fh;
+ }
+
+
+}
+
+=item B<tempdir>
+
+This is the recommended interface for creation of temporary directories.
+The behaviour of the function depends on the arguments:
+
+ $tempdir = tempdir();
+
+Create a directory in tmpdir() (see L<File::Spec|File::Spec>).
+
+ $tempdir = tempdir( $template );
+
+Create a directory from the supplied template. This template is
+similar to that described for tempfile(). `X' characters at the end
+of the template are replaced with random letters to construct the
+directory name. At least four `X' characters must be in the template.
+
+ $tempdir = tempdir ( DIR => $dir );
+
+Specifies the directory to use for the temporary directory.
+The temporary directory name is derived from an internal template.
+
+ $tempdir = tempdir ( $template, DIR => $dir );
+
+Prepend the supplied directory name to the template. The template
+should not include parent directory specifications itself. Any parent
+directory specifications are removed from the template before
+prepending the supplied directory.
+
+ $tempdir = tempdir ( $template, TMPDIR => 1 );
+
+Using the supplied template, create the temporary directory in
+a standard location for temporary files. Equivalent to doing
+
+ $tempdir = tempdir ( $template, DIR => File::Spec->tmpdir);
+
+but shorter. Parent directory specifications are stripped from the
+template itself. The C<TMPDIR> option is ignored if C<DIR> is set
+explicitly. Additionally, C<TMPDIR> is implied if neither a template
+nor a directory are supplied.
+
+ $tempdir = tempdir( $template, CLEANUP => 1);
+
+Create a temporary directory using the supplied template, but
+attempt to remove it (and all files inside it) when the program
+exits. Note that an attempt will be made to remove all files from
+the directory even if they were not created by this module (otherwise
+why ask to clean it up?). The directory removal is made with
+the rmtree() function from the L<File::Path|File::Path> module.
+Of course, if the template is not specified, the temporary directory
+will be created in tmpdir() and will also be removed at program exit.
+
+=cut
+
+# '
+
+sub tempdir {
+
+ # Can not check for argument count since we can have any
+ # number of args
+
+ # Default options
+ my %options = (
+ "CLEANUP" => 0, # Remove directory on exit
+ "DIR" => '', # Root directory
+ "TMPDIR" => 0, # Use tempdir with template
+ );
+
+ # Check to see whether we have an odd or even number of arguments
+ my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef );
+
+ # Read the options and merge with defaults
+ %options = (%options, @_) if @_;
+
+ # Modify or generate the template
+
+ # Deal with the DIR and TMPDIR options
+ if (defined $template) {
+
+ # Need to strip directory path if using DIR or TMPDIR
+ if ($options{'TMPDIR'} || $options{'DIR'}) {
+
+ # Strip parent directory from the filename
+ #
+ # There is no filename at the end
+ $template = VMS::Filespec::vmspath($template) if $^O eq 'VMS';
+ my ($volume, $directories, undef) = File::Spec->splitpath( $template, 1);
+
+ # Last directory is then our template
+ $template = (File::Spec->splitdir($directories))[-1];
+
+ # Prepend the supplied directory or temp dir
+ if ($options{"DIR"}) {
+
+ $template = File::Spec->catdir($options{"DIR"}, $template);
+
+ } elsif ($options{TMPDIR}) {
+
+ # Prepend tmpdir
+ $template = File::Spec->catdir(File::Spec->tmpdir, $template);
+
+ }
+
+ }
+
+ } else {
+
+ if ($options{"DIR"}) {
+
+ $template = File::Spec->catdir($options{"DIR"}, TEMPXXX);
+
+ } else {
+
+ $template = File::Spec->catdir(File::Spec->tmpdir, TEMPXXX);
+
+ }
+
+ }
+
+ # Create the directory
+ my $tempdir;
+ my $suffixlen = 0;
+ if ($^O eq 'VMS') { # dir names can end in delimiters
+ $template =~ m/([\.\]:>]+)$/;
+ $suffixlen = length($1);
+ }
+ if ( ($^O eq 'MacOS') && (substr($template, -1) eq ':') ) {
+ # dir name has a trailing ':'
+ ++$suffixlen;
+ }
+
+ my $errstr;
+ croak "Error in tempdir() using $template: $errstr"
+ unless ((undef, $tempdir) = _gettemp($template,
+ "open" => 0,
+ "mkdir"=> 1 ,
+ "suffixlen" => $suffixlen,
+ "ErrStr" => \$errstr,
+ ) );
+
+ # Install exit handler; must be dynamic to get lexical
+ if ( $options{'CLEANUP'} && -d $tempdir) {
+ _deferred_unlink(undef, $tempdir, 1);
+ }
+
+ # Return the dir name
+ return $tempdir;
+
+}
+
+=back
+
+=head1 MKTEMP FUNCTIONS
+
+The following functions are Perl implementations of the
+mktemp() family of temp file generation system calls.
+
+=over 4
+
+=item B<mkstemp>
+
+Given a template, returns a filehandle to the temporary file and the name
+of the file.
+
+ ($fh, $name) = mkstemp( $template );
+
+In scalar context, just the filehandle is returned.
+
+The template may be any filename with some number of X's appended
+to it, for example F</tmp/temp.XXXX>. The trailing X's are replaced
+with unique alphanumeric combinations.
+
+=cut
+
+
+
+sub mkstemp {
+
+ croak "Usage: mkstemp(template)"
+ if scalar(@_) != 1;
+
+ my $template = shift;
+
+ my ($fh, $path, $errstr);
+ croak "Error in mkstemp using $template: $errstr"
+ unless (($fh, $path) = _gettemp($template,
+ "open" => 1,
+ "mkdir"=> 0 ,
+ "suffixlen" => 0,
+ "ErrStr" => \$errstr,
+ ) );
+
+ if (wantarray()) {
+ return ($fh, $path);
+ } else {
+ return $fh;
+ }
+
+}
+
+
+=item B<mkstemps>
+
+Similar to mkstemp(), except that an extra argument can be supplied
+with a suffix to be appended to the template.
+
+ ($fh, $name) = mkstemps( $template, $suffix );
+
+For example a template of C<testXXXXXX> and suffix of C<.dat>
+would generate a file similar to F<testhGji_w.dat>.
+
+Returns just the filehandle alone when called in scalar context.
+
+=cut
+
+sub mkstemps {
+
+ croak "Usage: mkstemps(template, suffix)"
+ if scalar(@_) != 2;
+
+
+ my $template = shift;
+ my $suffix = shift;
+
+ $template .= $suffix;
+
+ my ($fh, $path, $errstr);
+ croak "Error in mkstemps using $template: $errstr"
+ unless (($fh, $path) = _gettemp($template,
+ "open" => 1,
+ "mkdir"=> 0 ,
+ "suffixlen" => length($suffix),
+ "ErrStr" => \$errstr,
+ ) );
+
+ if (wantarray()) {
+ return ($fh, $path);
+ } else {
+ return $fh;
+ }
+
+}
+
+=item B<mkdtemp>
+
+Create a directory from a template. The template must end in
+X's that are replaced by the routine.
+
+ $tmpdir_name = mkdtemp($template);
+
+Returns the name of the temporary directory created.
+Returns undef on failure.
+
+Directory must be removed by the caller.
+
+=cut
+
+#' # for emacs
+
+sub mkdtemp {
+
+ croak "Usage: mkdtemp(template)"
+ if scalar(@_) != 1;
+
+ my $template = shift;
+ my $suffixlen = 0;
+ if ($^O eq 'VMS') { # dir names can end in delimiters
+ $template =~ m/([\.\]:>]+)$/;
+ $suffixlen = length($1);
+ }
+ if ( ($^O eq 'MacOS') && (substr($template, -1) eq ':') ) {
+ # dir name has a trailing ':'
+ ++$suffixlen;
+ }
+ my ($junk, $tmpdir, $errstr);
+ croak "Error creating temp directory from template $template\: $errstr"
+ unless (($junk, $tmpdir) = _gettemp($template,
+ "open" => 0,
+ "mkdir"=> 1 ,
+ "suffixlen" => $suffixlen,
+ "ErrStr" => \$errstr,
+ ) );
+
+ return $tmpdir;
+
+}
+
+=item B<mktemp>
+
+Returns a valid temporary filename but does not guarantee
+that the file will not be opened by someone else.
+
+ $unopened_file = mktemp($template);
+
+Template is the same as that required by mkstemp().
+
+=cut
+
+sub mktemp {
+
+ croak "Usage: mktemp(template)"
+ if scalar(@_) != 1;
+
+ my $template = shift;
+
+ my ($tmpname, $junk, $errstr);
+ croak "Error getting name to temp file from template $template: $errstr"
+ unless (($junk, $tmpname) = _gettemp($template,
+ "open" => 0,
+ "mkdir"=> 0 ,
+ "suffixlen" => 0,
+ "ErrStr" => \$errstr,
+ ) );
+
+ return $tmpname;
+}
+
+=back
+
+=head1 POSIX FUNCTIONS
+
+This section describes the re-implementation of the tmpnam()
+and tmpfile() functions described in L<POSIX>
+using the mkstemp() from this module.
+
+Unlike the L<POSIX|POSIX> implementations, the directory used
+for the temporary file is not specified in a system include
+file (C<P_tmpdir>) but simply depends on the choice of tmpdir()
+returned by L<File::Spec|File::Spec>. On some implementations this
+location can be set using the C<TMPDIR> environment variable, which
+may not be secure.
+If this is a problem, simply use mkstemp() and specify a template.
+
+=over 4
+
+=item B<tmpnam>
+
+When called in scalar context, returns the full name (including path)
+of a temporary file (uses mktemp()). The only check is that the file does
+not already exist, but there is no guarantee that that condition will
+continue to apply.
+
+ $file = tmpnam();
+
+When called in list context, a filehandle to the open file and
+a filename are returned. This is achieved by calling mkstemp()
+after constructing a suitable template.
+
+ ($fh, $file) = tmpnam();
+
+If possible, this form should be used to prevent possible
+race conditions.
+
+See L<File::Spec/tmpdir> for information on the choice of temporary
+directory for a particular operating system.
+
+=cut
+
+sub tmpnam {
+
+ # Retrieve the temporary directory name
+ my $tmpdir = File::Spec->tmpdir;
+
+ croak "Error temporary directory is not writable"
+ if $tmpdir eq '';
+
+ # Use a ten character template and append to tmpdir
+ my $template = File::Spec->catfile($tmpdir, TEMPXXX);
+
+ if (wantarray() ) {
+ return mkstemp($template);
+ } else {
+ return mktemp($template);
+ }
+
+}
+
+=item B<tmpfile>
+
+In scalar context, returns the filehandle of a temporary file.
+
+ $fh = tmpfile();
+
+The file is removed when the filehandle is closed or when the program
+exits. No access to the filename is provided.
+
+If the temporary file can not be created undef is returned.
+Currently this command will probably not work when the temporary
+directory is on an NFS file system.
+
+=cut
+
+sub tmpfile {
+
+ # Simply call tmpnam() in a list context
+ my ($fh, $file) = tmpnam();
+
+ # Make sure file is removed when filehandle is closed
+ # This will fail on NFS
+ unlink0($fh, $file)
+ or return undef;
+
+ return $fh;
+
+}
+
+=back
+
+=head1 ADDITIONAL FUNCTIONS
+
+These functions are provided for backwards compatibility
+with common tempfile generation C library functions.
+
+They are not exported and must be addressed using the full package
+name.
+
+=over 4
+
+=item B<tempnam>
+
+Return the name of a temporary file in the specified directory
+using a prefix. The file is guaranteed not to exist at the time
+the function was called, but such guarantees are good for one
+clock tick only. Always use the proper form of C<sysopen>
+with C<O_CREAT | O_EXCL> if you must open such a filename.
+
+ $filename = File::Temp::tempnam( $dir, $prefix );
+
+Equivalent to running mktemp() with $dir/$prefixXXXXXXXX
+(using unix file convention as an example)
+
+Because this function uses mktemp(), it can suffer from race conditions.
+
+=cut
+
+sub tempnam {
+
+ croak 'Usage tempnam($dir, $prefix)' unless scalar(@_) == 2;
+
+ my ($dir, $prefix) = @_;
+
+ # Add a string to the prefix
+ $prefix .= 'XXXXXXXX';
+
+ # Concatenate the directory to the file
+ my $template = File::Spec->catfile($dir, $prefix);
+
+ return mktemp($template);
+
+}
+
+=back
+
+=head1 UTILITY FUNCTIONS
+
+Useful functions for dealing with the filehandle and filename.
+
+=over 4
+
+=item B<unlink0>
+
+Given an open filehandle and the associated filename, make a safe
+unlink. This is achieved by first checking that the filename and
+filehandle initially point to the same file and that the number of
+links to the file is 1 (all fields returned by stat() are compared).
+Then the filename is unlinked and the filehandle checked once again to
+verify that the number of links on that file is now 0. This is the
+closest you can come to making sure that the filename unlinked was the
+same as the file whose descriptor you hold.
+
+ unlink0($fh, $path) or die "Error unlinking file $path safely";
+
+Returns false on error. The filehandle is not closed since on some
+occasions this is not required.
+
+On some platforms, for example Windows NT, it is not possible to
+unlink an open file (the file must be closed first). On those
+platforms, the actual unlinking is deferred until the program ends and
+good status is returned. A check is still performed to make sure that
+the filehandle and filename are pointing to the same thing (but not at
+the time the end block is executed since the deferred removal may not
+have access to the filehandle).
+
+Additionally, on Windows NT not all the fields returned by stat() can
+be compared. For example, the C<dev> and C<rdev> fields seem to be
+different. Also, it seems that the size of the file returned by stat()
+does not always agree, with C<stat(FH)> being more accurate than
+C<stat(filename)>, presumably because of caching issues even when
+using autoflush (this is usually overcome by waiting a while after
+writing to the tempfile before attempting to C<unlink0> it).
+
+Finally, on NFS file systems the link count of the file handle does
+not always go to zero immediately after unlinking. Currently, this
+command is expected to fail on NFS disks.
+
+=cut
+
+sub unlink0 {
+
+ croak 'Usage: unlink0(filehandle, filename)'
+ unless scalar(@_) == 2;
+
+ # Read args
+ my ($fh, $path) = @_;
+
+ warn "Unlinking $path using unlink0\n"
+ if $DEBUG;
+
+ # Stat the filehandle
+ my @fh = stat $fh;
+
+ if ($fh[3] > 1 && $^W) {
+ carp "unlink0: fstat found too many links; SB=@fh" if $^W;
+ }
+
+ # Stat the path
+ my @path = stat $path;
+
+ unless (@path) {
+ carp "unlink0: $path is gone already" if $^W;
+ return;
+ }
+
+ # this is no longer a file, but may be a directory, or worse
+ unless (-f _) {
+ confess "panic: $path is no longer a file: SB=@fh";
+ }
+
+ # Do comparison of each member of the array
+ # On WinNT dev and rdev seem to be different
+ # depending on whether it is a file or a handle.
+ # Cannot simply compare all members of the stat return
+ # Select the ones we can use
+ my @okstat = (0..$#fh); # Use all by default
+ if ($^O eq 'MSWin32') {
+ @okstat = (1,2,3,4,5,7,8,9,10);
+ } elsif ($^O eq 'os2') {
+ @okstat = (0, 2..$#fh);
+ } elsif ($^O eq 'VMS') { # device and file ID are sufficient
+ @okstat = (0, 1);
+ } elsif ($^O eq 'dos') {
+ @okstat = (0,2..7,11..$#fh);
+ }
+
+ # Now compare each entry explicitly by number
+ for (@okstat) {
+ print "Comparing: $_ : $fh[$_] and $path[$_]\n" if $DEBUG;
+ # Use eq rather than == since rdev, blksize, and blocks (6, 11,
+ # and 12) will be '' on platforms that do not support them. This
+ # is fine since we are only comparing integers.
+ unless ($fh[$_] eq $path[$_]) {
+ warn "Did not match $_ element of stat\n" if $DEBUG;
+ return 0;
+ }
+ }
+
+ # attempt remove the file (does not work on some platforms)
+ if (_can_unlink_opened_file()) {
+ # XXX: do *not* call this on a directory; possible race
+ # resulting in recursive removal
+ croak "unlink0: $path has become a directory!" if -d $path;
+ unlink($path) or return 0;
+
+ # Stat the filehandle
+ @fh = stat $fh;
+
+ print "Link count = $fh[3] \n" if $DEBUG;
+
+ # Make sure that the link count is zero
+ # - Cygwin provides deferred unlinking, however,
+ # on Win9x the link count remains 1
+ # On NFS the link count may still be 1 but we cant know that
+ # we are on NFS
+ return ( $fh[3] == 0 or $^O eq 'cygwin' ? 1 : 0);
+
+ } else {
+ _deferred_unlink($fh, $path, 0);
+ return 1;
+ }
+
+}
+
+=back
+
+=head1 PACKAGE VARIABLES
+
+These functions control the global state of the package.
+
+=over 4
+
+=item B<safe_level>
+
+Controls the lengths to which the module will go to check the safety of the
+temporary file or directory before proceeding.
+Options are:
+
+=over 8
+
+=item STANDARD
+
+Do the basic security measures to ensure the directory exists and
+is writable, that the umask() is fixed before opening of the file,
+that temporary files are opened only if they do not already exist, and
+that possible race conditions are avoided. Finally the L<unlink0|"unlink0">
+function is used to remove files safely.
+
+=item MEDIUM
+
+In addition to the STANDARD security, the output directory is checked
+to make sure that it is owned either by root or the user running the
+program. If the directory is writable by group or by other, it is then
+checked to make sure that the sticky bit is set.
+
+Will not work on platforms that do not support the C<-k> test
+for sticky bit.
+
+=item HIGH
+
+In addition to the MEDIUM security checks, also check for the
+possibility of ``chown() giveaway'' using the L<POSIX|POSIX>
+sysconf() function. If this is a possibility, each directory in the
+path is checked in turn for safeness, recursively walking back to the
+root directory.
+
+For platforms that do not support the L<POSIX|POSIX>
+C<_PC_CHOWN_RESTRICTED> symbol (for example, Windows NT) it is
+assumed that ``chown() giveaway'' is possible and the recursive test
+is performed.
+
+=back
+
+The level can be changed as follows:
+
+ File::Temp->safe_level( File::Temp::HIGH );
+
+The level constants are not exported by the module.
+
+Currently, you must be running at least perl v5.6.0 in order to
+run with MEDIUM or HIGH security. This is simply because the
+safety tests use functions from L<Fcntl|Fcntl> that are not
+available in older versions of perl. The problem is that the version
+number for Fcntl is the same in perl 5.6.0 and in 5.005_03 even though
+they are different versions.
+
+On systems that do not support the HIGH or MEDIUM safety levels
+(for example Win NT or OS/2) any attempt to change the level will
+be ignored. The decision to ignore rather than raise an exception
+allows portable programs to be written with high security in mind
+for the systems that can support this without those programs failing
+on systems where the extra tests are irrelevant.
+
+If you really need to see whether the change has been accepted
+simply examine the return value of C<safe_level>.
+
+ $newlevel = File::Temp->safe_level( File::Temp::HIGH );
+ die "Could not change to high security"
+ if $newlevel != File::Temp::HIGH;
+
+=cut
+
+{
+ # protect from using the variable itself
+ my $LEVEL = STANDARD;
+ sub safe_level {
+ my $self = shift;
+ if (@_) {
+ my $level = shift;
+ if (($level != STANDARD) && ($level != MEDIUM) && ($level != HIGH)) {
+ carp "safe_level: Specified level ($level) not STANDARD, MEDIUM or HIGH - ignoring\n" if $^W;
+ } else {
+ # Dont allow this on perl 5.005 or earlier
+ if ($] < 5.006 && $level != STANDARD) {
+ # Cant do MEDIUM or HIGH checks
+ croak "Currently requires perl 5.006 or newer to do the safe checks";
+ }
+ # Check that we are allowed to change level
+ # Silently ignore if we can not.
+ $LEVEL = $level if _can_do_level($level);
+ }
+ }
+ return $LEVEL;
+ }
+}
+
+=item TopSystemUID
+
+This is the highest UID on the current system that refers to a root
+UID. This is used to make sure that the temporary directory is
+owned by a system UID (C<root>, C<bin>, C<sys> etc) rather than
+simply by root.
+
+This is required since on many unix systems C</tmp> is not owned
+by root.
+
+Default is to assume that any UID less than or equal to 10 is a root
+UID.
+
+ File::Temp->top_system_uid(10);
+ my $topid = File::Temp->top_system_uid;
+
+This value can be adjusted to reduce security checking if required.
+The value is only relevant when C<safe_level> is set to MEDIUM or higher.
+
+=back
+
+=cut
+
+{
+ my $TopSystemUID = 10;
+ sub top_system_uid {
+ my $self = shift;
+ if (@_) {
+ my $newuid = shift;
+ croak "top_system_uid: UIDs should be numeric"
+ unless $newuid =~ /^\d+$/s;
+ $TopSystemUID = $newuid;
+ }
+ return $TopSystemUID;
+ }
+}
+
+=head1 WARNING
+
+For maximum security, endeavour always to avoid ever looking at,
+touching, or even imputing the existence of the filename. You do not
+know that that filename is connected to the same file as the handle
+you have, and attempts to check this can only trigger more race
+conditions. It's far more secure to use the filehandle alone and
+dispense with the filename altogether.
+
+If you need to pass the handle to something that expects a filename
+then, on a unix system, use C<"/dev/fd/" . fileno($fh)> for arbitrary
+programs, or more generally C<< "+<=&" . fileno($fh) >> for Perl
+programs. You will have to clear the close-on-exec bit on that file
+descriptor before passing it to another process.
+
+ use Fcntl qw/F_SETFD F_GETFD/;
+ fcntl($tmpfh, F_SETFD, 0)
+ or die "Can't clear close-on-exec flag on temp fh: $!\n";
+
+=head2 Temporary files and NFS
+
+Some problems are associated with using temporary files that reside
+on NFS file systems and it is recommended that a local filesystem
+is used whenever possible. Some of the security tests will most probably
+fail when the temp file is not local. Additionally, be aware that
+the performance of I/O operations over NFS will not be as good as for
+a local disk.
+
+=head1 HISTORY
+
+Originally began life in May 1999 as an XS interface to the system
+mkstemp() function. In March 2000, the OpenBSD mkstemp() code was
+translated to Perl for total control of the code's
+security checking, to ensure the presence of the function regardless of
+operating system and to help with portability.
+
+=head1 SEE ALSO
+
+L<POSIX/tmpnam>, L<POSIX/tmpfile>, L<File::Spec>, L<File::Path>
+
+See L<IO::File> and L<File::MkTemp> for different implementations of
+temporary file handling.
+
+=head1 AUTHOR
+
+Tim Jenness E<lt>t.jenness@jach.hawaii.eduE<gt>
+
+Copyright (C) 1999-2001 Tim Jenness and the UK Particle Physics and
+Astronomy Research Council. All Rights Reserved. This program is free
+software; you can redistribute it and/or modify it under the same
+terms as Perl itself.
+
+Original Perl implementation loosely based on the OpenBSD C code for
+mkstemp(). Thanks to Tom Christiansen for suggesting that this module
+should be written and providing ideas for code improvements and
+security enhancements.
+
+=cut
+
+
+1;