#!/usr/bin/perl
use strict;
my $file_name = "read.pl";
open my $f, "<", $file_name
    or die "Can't open $file_name: $!";
my $lines = 0;
while (<$f>) {
    $lines += 1;
}
close $f
    or die "Can't close $file_name: $!";
print "There are $lines lines in $file_name.\n";