#!/usr/bin/perl

use strict;
use warnings;
use LWP::UserAgent;

my $USPS = 'http://www.usps.com/cgi-bin/zip4/ctystzip2';
my $FormDataID = 'ctystzip';
my ($x, @matches);

if (@ARGV) { $x = join " ", @ARGV; }
else { print 'Enter Search (zip code OR city, state): ';
       chomp( $x = <STDIN> ); }

# Prepare data to send to the USPS
my $ua = new LWP::UserAgent;
my $req = new HTTP::Request POST => $USPS;
$req->content_type('application/x-www-form-urlencoded');
$req->content($FormDataID.'='.$x); # HTTP::Request handles URL encoding.

# Request the page, and ignore initial content
my $res = $ua->request($req);
my $data = $res->content;
$data =~ /----------</g;


# If a zip code was submitted, we are looking for CITY   STATE
if ($x =~ /^\s*\d{5}\s*/) {
    while ($data =~ /\G.*?br>\s*((\w+\s)+\s*\w\w) /ig) {
	push @matches, $1; }
    @matches = map { $_ = reverse $_;
		     /^\s*(\w\w)\s*(\w.*)$/;
		     scalar reverse "$1 ,$2"; }
               @matches;
}
# Otherwise, Extract the zip codes.
else {

    while ($data =~ /\G.*?br>\s*(\d{5})/ig) {
	push @matches, $1; }
    for (@matches) { s/^\s+//; s/\s+$//; }
}

print 'Found ',$#matches+1," matches for $x\n  ",
      join("\n  ", @matches),"\n";

__END__

=head1 NAME

zipcode.pl - City, State to/from Zip Code converter

=head1 SYNOPSIS

 perl zipcode.pl [City, State]

 or

 perl zipcode.pl [Zip Code]

=head1 AUTHOR

Dean Serenevy <dean@serenevy.net>

=cut