open(FILE, "<myfile.txt");
@file = reverse <FILE>;
foreach (@file) {
    #process line
}

##</code><code>##


#!/usr/bin/perl
use CGI ':standard';
use strict;
use warnings;
use CGI::Carp 'fatalsToBrowser'; # use only for testing

#my $date = localtime();

$ENV{"PATH"} = "/usr/sbin:/usr/bin:/sbin:/bin";

open FILE, '<', '/var/log/maillog' or die $!;

while (<FILE>){
   chomp;
   next unless /\S/; # skip blank lines
   if (/Passed CLEAN/) { #search string Passed CLEAN
      print "$_ \n"; # print ALL lines containing Passed CLEAN

   }
}

close FILE;