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 $h{oldkey};
...
untie %h;
=head1 DESCRIPTION
C establishes a connection between a Perl hash variable and
a file in SDBM_File format;. You can manipulate the data in the file
just as if it were in a Perl hash, but when your program exits, the
data will remain in the file, to be used the next time your program
runs.
Use C with the Perl built-in C function to establish
the connection between the variable and the file. The arguments to
C should be:
=over 4
=item 1.
The hash variable you want to tie.
=item 2.
The string C<"SDBM_File">. (Ths tells Perl to use the C
package to perform the functions of the hash.)
=item 3.
The name of the file you want to tie to the hash.
=item 4.
Flags. Use one of:
=over 2
=item C
Read-only access to the data in the file.
=item C
Write-only access to the data in the file.
=item C
Both read and write access.
=back
If you want to create the file if it does not exist, add C to
any of these, as in the example. If you omit C and the file
does not already exist, the C call will fail.
=item 5.
The default permissions to use if a new file is created. The actual
permissions will be modified by the user's umask, so you should
probably use 0666 here. (See L.)
=back
=head1 DIAGNOSTICS
On failure, the C call returns an undefined value and probably
sets C<$!> to contain the reason the file could not be tied.
=head2 C
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, L, L
=cut