#!/usr/local/bin/perl -w
 use strict;
 use Sysadm::Install qw(:all);
 use LWP::Simple ;
 use HTML::TreeBuilder::XPath;
 use Log::Log4perl qw(:easy);

 my $nick      = "my-ebay-name";
 my $ebay_url  =
   "http://feedback.ebay.com" .
   "/ws/eBayISAPI.dll?ViewFeedback2" .
   "&userid=$nick";

 my( $home )   = glob "~";
 my $data_dir  = "$home/logs";
 my $cache     =
   "$data_dir/ebay-feedback.cache";
 my $log_file  =
   "$data_dir/ebay-feedback.log";

   # mail prefs
 my $mailer    = "/usr/bin/mail";
 my $mail_to   = 'my@email.com';

 mkd $data_dir if !-d $data_dir;

 Log::Log4perl->easy_init( {
   level => $DEBUG,
   file => ">>$log_file" } );

 my $last_feedback;

 if( -f $cache ) {
   $last_feedback = slurp $cache;
 }

 my $feedback = feedback_fetch();

 if( !defined $last_feedback or
   $last_feedback != $feedback ) {

   $last_feedback ||= 0;

   INFO "New feedback: $feedback";
   INFO "Sending mail to $mail_to";

   open PIPE,
     "| $mailer -s 'New Ebay Feedback: " .
     "$feedback' $mail_to";

   print PIPE <<EOT;
 Ebay feedback changed: It's $feedback now
 and was $last_feedback yesterday:

     $ebay_url

 Greetings!

 Your faithful Ebay feedback scraper.
 EOT
   close PIPE;

   blurt $feedback, $cache;

 } else {
   INFO "Feedback unchanged ($feedback).";
 }

 ###########################################
 sub feedback_fetch {
 ###########################################
   INFO "Fetching $ebay_url";

   my $content = get $ebay_url;

   if( !defined $content ) {
     ERROR "Fetching $ebay_url failed";
     return undef;
   }

   my $tree= HTML::TreeBuilder::XPath->new;
   $tree->parse( $content );

   my( $text ) = $tree->findvalue(
       '/html/body//span[@class="mbg-l"]');

   if( $text =~ /\s*(\d+)/ ) {
     return $1;
   }

   ERROR "Pattern in page not found";
   return undef;
 }