Simple URL checker. All it does is check a predefined url to see if it has changes over the time. If it did , then it sends you an e-mail. It is useful when your are waiting for something on a website to change!

url_checker.pl

#!/usr/bin/perl -W
use strict;
use warnings;
use LWP::Simple;
use Digest::MD5 qw(md5 md5_hex md5_base64);
use Encode qw(encode_utf8);
 
my $link 		= [URL TO BE CHECKED];
my $email_from          = [FROM EMAIL];
my $email               = [TO EMAIL];
my $email_subject       = 'Website Changed!';
my $email_body          = 'Hello! I just want to let you know that the website ' 
                          . $link . ' has just changed!';
my $tmp_file            = '/tmp/stored_hash';
 
my $web_source = get( $link );
my $current_hash =  md5_hex(encode_utf8($web_source));
 
if(-e $tmp_file)
{
        open FH, "<$tmp_file" or die "could not open: $!\n";
        my $mod_hash = <FH>;
        if( $current_hash ne $mod_hash )
        {
                open(MAIL, "|/usr/sbin/sendmail -t");
                print MAIL "To: $email\n";
                print MAIL "From: $email_from\n";
                print MAIL "Subject: $email_subject\n\n";
                print MAIL "$email_body\n";
                close(MAIL);
        }
        close FH;
}
        open FH, ">$tmp_file" or die "could not create: $!\n";
        print FH $current_hash;
        close FH;