The Code

This script takes a Purchase Circle ID and returns the books listed. Create a file called get_circle.pl and add the following code:

#!/usr/bin/perl
# get_circle.pl
# A script to scrape Amazon to retrieve purchase circle products
# Usage: perl get_circle.pl <circleID>

#Take the asin from the command-line
my $circleID =shift @ARGV or die "Usage:perl get_circle.pl <circleID>\n";

#Assemble the URL
my $url = "http://amazon.com/o/tg/cm/browse-communities/-/" .
          $circleID . "/t/";

use strict;
use LWP::Simple;

#Request the URL
my $content = get($url);
die "Could not retrieve $url" unless $content;

my $circle = (join '', $content);

while ($circle =~ m!<title>(.*?)</title>!mgis) {
    print $1 . "\n\n";
}

while ($circle =~ m!<td.*?<b><a.*?-/(.*?)[?/].*?>(.*?)</a></b>.*?by&return;
(.*?)<br>.*?</td>!mgis) {
    my($asin,$title,$author) = ($1||'',$2||'',$3||'');
    #Print the results
    print $title . "\n" .
          "by " . $author . "\n" .  
          "ASIN: " . $asin .
          "\n\n";
}

One thing to note about this code is that it passes the /t/ URL argument to return a text-only version of the purchase circle page. Text-only pages have less HTML, which means that fewer bytes are flying around and it's generally easier to scrape for information.