#!/usr/bin/perl
use strict;
use IO::File;
my $file = "yourFile.txt";
my $counter = 0;
my $fh = IO::File->new($file) or die "Can't open $file: $!\n";
while ( defined (my $line = $fh->getline) ) {
$counter++;
}
STDOUT->print("Counted $counter lines\n");