#!/usr/bin/perl -w
use strict;

my %Isbn2Title;
while (<DATA>)
{
   next unless (my $ISBN = (m/\|a\s+(\d{13})/)[0]);

   my $title = get_title();
   $title =~s/\s+$//;  #delete trailing whitespace

   ${Isbn2Title}{$ISBN}=$title;
}

foreach my $isbn (sort keys %Isbn2Title)
{
   print "ISBN=$isbn title=$Isbn2Title{$isbn}\n";
}

#Prints: ISBN=9780470086223 title=Heads in the sand

sub get_title
{
   while (<DATA>)
   {
     my $title = (m/\|a\s+(.*?)[\|:]/)[0];
     return $title if $title;
   }
}

__DATA__
<!-- filename: full-000-body-cdl90 --> 
 <tr> 
  <td class="contentSmall" valign="top" id=bold width="5%" nowrap><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;020</strong></td> 
  <td class="contentSmall" valign="top">|a 9780470086223 (hardback)</td> 
 </tr> 
<!-- end: full-000-body-cdl90 --> 

<!-- filename: full-000-body-cdl90 --> 
 <tr> 
  <td class="contentSmall" valign="top" id=bold width="5%" nowrap><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;24510</strong></td> 
  <td class="contentSmall" valign="top">|a Heads in the sand : |b how the Republicans screw up foreign policy and foreign policy screws up the Democrats / |c Matthew Yglesias</td> 
 </tr> 
<!-- end: full-000-body-cdl90 --> 

<!-- filename: full-000-body-cdl90 --> 
 <tr> 
  <td class="contentSmall" valign="top" id=bold width="5%" nowrap><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;24610</strong></td> 
  <td class="contentSmall" valign="top">|a How the Republicans screw up foreign policy and foreign policy screws up the Democrats</td> 
 </tr> 
<!-- end: full-000-body-cdl90 --> 

<!-- filename: full-000-body-cdl90 --> 
 <tr> 
  <td class="contentSmall" valign="top" id=bold width="5%" nowrap><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;61020</strong></td> 
  <td class="contentSmall" valign="top">|a Democratic Party (U.S.)</td> 
 </tr> 
<!-- end: full-000-body-cdl90 -->