#!/usr/bin/perl
use Fcntl ':flock';

use strict;

my $lockfile = shift;

if( not $lockfile) {
   $lockfile = "test_lock_file";
}   

if ( not open ( LOCKFILE, ">> $lockfile"))  {
	    print "Cannot open $lockfile\n";
            exit 1;
}

print "Waiting for lock $lockfile.\n";

flock LOCKFILE, LOCK_EX;

print "Got lock.\n";

getc;

flock LOCKFILE, LOCK_UN;

close LOCKFILE;