Im making a script that takes an URL as an input and checks for its existance. The current code I came up with is this:

#!/usr/bin/perl -w

use strict;
use CGI::Carp qw(fatalsToBrowser);
use CGI;

        my $q = new CGI;

        my $url = $q->params('url');

        my $ua = LWP::UserAgent->new;
        my $request = HTTP::Request->new(GET => $url);
        my $response = $ua->request($request);


        my $string = $response->content;

        $string =~ s/\n//gi;

        if($string =~ /404 Not Found/ or $string eq ''){
            print "$url - Doesn't exist\n";
            next;
        }else{
             print "$url - Does exist\n";
             next;
                 }
[download]

What I do is that I fetch the URL and then check for either the string "404 Not Found" in the $tring or for it to be empty.

The problem with this approach is that there may be a possibilitie that the page has some text that say "404 Not Found" as part of the content but it actually exists.

So I thought that maybe there will be some kind of headers that tell you what kind of response you got...maybe a 302 or a 501, but I got no idea of how can I achieve this.

Thanks