#!/usr/bin/perl
 use File::stat;

$file = "test.dat";
#$file = ".";

 $st = stat($file) or die "No $file: $!";
 $original_time = $st -> mtime;

while()
{
 $st = stat($file);
 $new_time = $st -> mtime;
 print "Time: " . $new_time . "\n";
 sleep 1;
}