package Triger;
use strict;
use Carp;

# Create tie hash
sub TIEHASH {
        my $self = shift;
        my $path = shift;
        my $mode = shift || 'r';

        if(@_) {
                croak("Usage: tie(\%hash, \$file, [mode])");
        my($line, $id, $status, $time_down, $time_up);
        foreach $line (@lines) {
                ($id,$status) = split(/=/,$line);
                ($time_down,$time_up) = split(/\|/,$status);
                $node->{CURRENT}{$id}{DOWN} = $time_down;
                $node->{CURRENT}{$id}{UP} = $time_up;
        }
        return bless $node => $self;
}

sub FETCH {
        my $self = shift;
        my ($id) = shift;
        if ( exists $self->{CURRENT}{$id} ) {
                return $self->{CURRENT}{$id};
        } else {
                return "$id doesn't exist";
        }
}

sub STORE {
        my $self = shift;
        my ($id) = shift;
        my($TFile) = $self->{PATH};
        my $time_down;
        my $time_up;
        my($return) = 0;
        my(@cache);
        unless($self->{CLOBBER}) {
                carp ("No write access for $self->{PATH}");
                return;
        }

        # open File
        if(!open(FH, "<TFile")) {
                carp("Cannot open $TFile: $!");
                return;
        }
        flock($TFile,2);
        if(!exists $self->{CURRENT}{$id}) {
                while(<FH>) {
                        if( /^$id\=/ ) {
                                push (@cache, "$id=$time_down|$time_up
+\n");
                                $return = 1
                        } else {
                                push (@cache, $_);
                        }
                }
        }
        close(FH);

        if($return) {
                # Writing to File
                if (!open(FH,">$TFile")) {
                        carp("Cannot open $TFile: $!");
                        return;
                }
                flock(FH, 2);
                while (@cache) {
                print FH shift (@cache);
                }
        } else {
                if(!open(FH,">>$TFile")) {
                        carp("Cannot open $TFile: $!");
                        return;
                }
                flock(FH,2);
                print FH "$id=$time_down|$time_up\n";

        }
        close(FH);
}
[download]

Edit kudra, 2002-04-16 Added readmore