See Regexp::Common::URI::http

#!/usr/bin/perl
use strict;
use warnings;
use Regexp::Common qw /URI/;


while(<DATA>){
chomp;
/$RE{URI}{HTTP}{-keep}/
        and  print "Contains an HTTP URI.\nHost=$3\n";
}

__DATA__
http://192.168.1.10/index.html
http://www.delicious.com/search?p=perl&chk=&context=main|&fr=del_icio_
+us&lc=
[download]

Output:
Contains an HTTP URI.
Host=192.168.1.10
Contains an HTTP URI.
Host=www.delicious.com

hth,
PooLpi