use warnings;
use strict;


##</code><code>##


chomp($pid  = $$);

##</code><code>##


$LOCK_EXCLUSIVE = 2;
$UNLOCK         = 8;

##</code><code>##

use Fcntl ':flock';

##</code><code>##


$fifo             = "ENV{HOME}/a_file";

##</code><code>##

$fifo             = "$ENV{HOME}/a_file";


##</code><code>##


close(FILE) || warn "update queue file exited $?\n";

##</code><code>##


close(LOCK) || warn "lock file exited $?\n";;
$str=`cat $fifo.lock`;

flock LOCK, $UNLOCK;

##</code><code>##


system("rm $fifo.lock");

##</code><code>##

#!/usr/local/bin/perl
use warnings;
use strict;

use Fcntl ':flock';
use Tie::File;

my $fifo = "$ENV{HOME}/a_file";
my $lock = "$fifo.lock";

tie( my @pid, 'Tie::File', $lock )->flock( LOCK_EX )
    or die "Cannot open '$lock' $!";

@pid = $$;

tie( my @lines, 'Tie::File', $fifo )->flock( LOCK_EX )
    or die "Cannot open '$fifo' $!";

( my $pop, @lines ) = sort @lines;

print "$hostname is poping $pop\n";

untie @lines;

print "PID lock file is going to be removed\n";

untie @pid;
unlink $lock or die "Cannot unlink '$lock' $!";

__END__