New tlperl part VIII

git-svn-id: svn://tug.org/texlive/trunk@21430 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 116 insertions, 0 deletions

diff --git a/Master/tlpkg/tlperl/lib/SDBM_File.pm b/Master/tlpkg/tlperl/lib/SDBM_File.pm
new file mode 100644
index 00000000000..d1209e0158b
--- /dev/null
+++ b/Master/tlpkg/tlperl/lib/SDBM_File.pm
@@ -0,0 +1,116 @@
+package SDBM_File;
+
+use strict;
+use warnings;
+
+require Tie::Hash;
+use XSLoader ();
+
+our @ISA = qw(Tie::Hash);
+our $VERSION = "1.06";
+
+XSLoader::load 'SDBM_File', $VERSION;
+
+1;
+
+__END__
+
+=head1 NAME
+
+SDBM_File - Tied access to sdbm files
+
+=head1 SYNOPSIS
+
+ use Fcntl;   # For O_RDWR, O_CREAT, etc.
+ use SDBM_File;
+
+ tie(%h, 'SDBM_File', 'filename', O_RDWR|O_CREAT, 0666)
+   or die "Couldn't tie SDBM file 'filename': $!; aborting";
+
+ # Now read and change the hash
+ $h{newkey} = newvalue;
+ print $h{oldkey}; 
+ ...
+
+ untie %h;
+
+=head1 DESCRIPTION
+
+C<SDBM_File> establishes a connection between a Perl hash variable and
+a file in SDBM_File format;.  You can manipulate the data in the file
+just as if it were in a Perl hash, but when your program exits, the
+data will remain in the file, to be used the next time your program
+runs.
+
+Use C<SDBM_File> with the Perl built-in C<tie> function to establish
+the connection between the variable and the file.  The arguments to
+C<tie> should be:
+
+=over 4
+
+=item 1.
+
+The hash variable you want to tie.
+
+=item 2. 
+
+The string C<"SDBM_File">.  (Ths tells Perl to use the C<SDBM_File>
+package to perform the functions of the hash.)
+
+=item 3. 
+
+The name of the file you want to tie to the hash.  
+
+=item 4.
+
+Flags.  Use one of:
+
+=over 2
+
+=item C<O_RDONLY>
+
+Read-only access to the data in the file.
+
+=item C<O_WRONLY>
+
+Write-only access to the data in the file.
+
+=item C<O_RDWR>
+
+Both read and write access.
+
+=back
+
+If you want to create the file if it does not exist, add C<O_CREAT> to
+any of these, as in the example.  If you omit C<O_CREAT> and the file
+does not already exist, the C<tie> call will fail.
+
+=item 5.
+
+The default permissions to use if a new file is created.  The actual
+permissions will be modified by the user's umask, so you should
+probably use 0666 here. (See L<perlfunc/umask>.)
+
+=back
+
+=head1 DIAGNOSTICS
+
+On failure, the C<tie> call returns an undefined value and probably
+sets C<$!> to contain the reason the file could not be tied.
+
+=head2 C<sdbm store returned -1, errno 22, key "..." at ...>
+
+This warning is emitted when you try to store a key or a value that
+is too long.  It means that the change was not recorded in the
+database.  See BUGS AND WARNINGS below.
+
+=head1 BUGS AND WARNINGS
+
+There are a number of limits on the size of the data that you can
+store in the SDBM file.  The most important is that the length of a
+key, plus the length of its associated value, may not exceed 1008
+bytes.
+
+See L<perlfunc/tie>, L<perldbmfilter>, L<Fcntl>
+
+=cut