#!/usr/bin/perl
use File::stat;
# Declare variables
my $filename;
my $FILE_HANDLE;
my $file_stat;
my $current_time;
my $diff_seconds;
$filename = '/path/of/file/filename.ext';
# Open the file
open ($FILE_HANDLE, $filename)
or die "Can't open $filename!";
# Get the file status structure
$file_stat = stat($FILE_HANDLE);
# Get the current time
$current_time = time;
# Get the elapsed time in seconds
$diff_seconds = time - $file_stat->mtime;
# Do whatever you want with the $diff_seconds
print "\n$filename was modified $diff_seconds seconds back.\n";
# All done