#! /usr/bin/perl -w

# $Cambridge: exim/doc/doc-docbook/PageLabelPDF,v 1.1 2006/02/01 11:01:01 ph10 Exp $

# Program to add page label information to the PDF output file. I have not
# found a way of automatically discovering the number of frontmatter pages
# in the document. It is therefore screwed in as 12 in the next statement.

$add = "/PageLabels << /Nums [ 0 << /S /r >>\n" .
       "                      12 << /S /D >>\n" .
       "                     ]\n" .
       "            >>\n";

$extra = length $add;

$before = 0;
while (<>)
  {
  print;
  $before += length($_);
  last if $_ =~ "^<< /Type /Catalog";
  }

print $add;

while (<>)
  {
  print;
  last if $_ =~ /^xref$/;
  }

while (<>)
  {
  if (/^(\d{10}) (.*)/)
    {
    my($was) = $1;
    my($rest) = $2;
    printf "%010d $rest\n", $was + (($was > $before)? $extra : 0);
    }
  elsif (/^startxref/)
    {
    print;
    $_ = <>;
    if (/^(\d+)/)
      {
      print $1 + $extra, "\n";
      }
    else
      {
      print;
      }
    }
  else
    {
    print;
    }
  }

# End