Developing Feeds with RSS and Atom

FedEx Parcel Tracker

Christmas is coming, and Santa has outsourced his deliveries to Federal Express. Lucky us, as that means we can use FedEx’s online shipment tracker to watch our parcels wend their merry way here. Except the tiresome chore of refreshing the FedEx site is just too much to handle. Let’s let a nice script elf take care of it and create a feed for every parcel.

Although FedEx and its rivals do provide APIs, we won’t be using them here. FedEx’s page is easy enough to scrape by brute force, and it’s fun to do so. Of course, when it next changes its page layout, this script will need rejigging. It’s easy to see how to do that when it happens.

Walking Through the Code

So, starting with the usual Perl standards of warnings;, strict;, XML::RSS, and CGI, let’s use LWP::Simple to retrieve the page and the marvellous HTML::TokeParser to do the dirty work. More on that anon.

use warnings;
use strict;
use XML::RSS;
use CGI qw(:standard);
use LWP::Simple 'get';
use HTML::TokeParser;

Now let’s set up some variables to use later, then fire up the CGI module and grab the tracking number from the query string. To use this script, therefore, you need to request:

http://www.example.org/fedextracker.cgi?track=123456789

where 123456789 is the tracking number of the parcel:

my ( $tag, $headline, $url, $date_line );
my $last_good_date;
my $table_end_check;

my $cgi             = CGI::new( );
my $tracking_number = $cgi->param('track');

Now we’re ready to jingle. Using LWP::Simple’s get method, pull down ...