#!/usr/bin/perl -w 

use strict;

print " please enter the domain name: ";

my  $targetdomain = <STDIN>;

chomp $targetdomain;

my  $file = "/home/blackice/hello";

open HAN,$file || die "error opening file: $!";
my @fileContent = <HAN>;
close(HAN);

for( my $i = 0; $i < @fileContent; $i++ ){
   if( $fileContent[$i] =~ m/^zone\s+"$targetdomain"/ ){
       $fileContent[$i] =~  s/\n/\n#/g;
   }
}

open HAN, ">$file";
print HAN @fileContent;
close(HAN);