#!/usr/bin/perl -w
use strict;
use Data::Dumper;

my $url = shift @ARGV || 'http://www.ietf.org/rfc/rfc2396.txt';
# [Page 28] "Parsing a URI Reference with a Regular Expression"
if (my @parts = ($url =~ m{
      ^(([^:/?#]+):)? #1-2 scheme
      (//([^/?#]*))?  #3-4 authority
      ([^?#]*)        #5 path
      (\?([^#]*))?    #6-7 query
      (\#(.*))?       #8-9 fragment
      }x)) {
   print Dumper(\@parts);
}
[download]