#!/usr/bin/perl

# This is a cgi script in perl.
#
# It creates PDF files of the number googolplex written out in
# book form. Since the number googolplex is too large to fit in
# a single book, it has been devided into many volumes. Each
# PDF file correponds to one of these volumes.
#
# The number of the requested volume is given to this program
# as a query string, for example if this program is available
# at http://www.GoogolplexWrittenOut.com/cgi-bin/makepdf.pl then one can
# get volume number 12345 as a PDF file
# at http://www.GoogolplexWrittenOut.com/cgi-bin/makepdf.pl?12345
# where "12345" is the query string. Setting the query string
# to "source", this means visiting something
# like http://www.GoogolplexWrittenOut.com/cgi-bin/makepdf.pl?source
# shows the source of this perl-script.
#
# This program returns the created pdf file via http and in
# the http header it mentions the canonical URL of the form
# http://www.GoogolplexWrittenOut.com/volume12345.pdf
# if in this example the query string was 12345.
# This means it assumes that the .htaccess file is used
# for URL rewriting.
#
# (all typed...)
#
# Wolfgang Hartmut Nitsche
# http://www.stanford.edu/~nitsche/
# http://nitsche.mobi
# http://www.GoogolplexWrittenOut.com


###########################################################
###########################################################
##                                                       ##
## I N I T I A L   P A R T   O F   T H I S   S C R I P T ##
##                                                       ##
###########################################################
###########################################################


$versiontext = "1.0.1";
# Text which should be included in the book to show the version.
# For example in the form Edition.MajorRevision.MinorRevision

use bytes;
# Probably this is not necessary, but just to be on the
# safe side, we use it anyway.
# I want to make sure that length() gives the number
# of bytes in a string, not the number of characters.
# So Windows-linebreak should have length 2.
# Special Unicode characters should have a length of more
# than 2, but we don't use them anyway.


$query = $ENV{'QUERY_STRING'};
# The query string should usually be the number of the requested volume.
# For example  $query = '123'  will produce the PDF file of book volume 123.
# Volume numbers must only consist of digits 0-9 and may not have any leading zero.
# And  $query = 'source'  will show the source code of this perl script.
# Any other invalid value for query will give error message.


$filename = $ENV{'SCRIPT_FILENAME'};
# This is the file-name of this perl script, for
# example  $filename = 'makepdf.pl'


# The number of the last volume of the books:
$voltotal = "1" . ("0" x 94);


# Get rid of unwanted special characters in $query
$query =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
$query =~ s/[^\!-\~]/\?/g;
$query =~ s/[\<\>\&]/\?/g;


# Show the source code of this perl script, if requested:
if($query eq 'source')
 {
  $sourcefile = '';
  open(FILE, "<$filename");
  while(<FILE>)
   {
    $sourcefile .= $_;
   }
  close(FILE);
  print "Content-type: text/plain\n\n";
  print $sourcefile;
  exit;
 }


# Check if $query is a valid volume number:
$errormessage = '';
if( $query eq '' )
 {
  $errormessage = 'requested volume number is an empty string';
 }
elsif( $query =~ /[^0-9]/ )
 {
  $errormessage = 'requested volume number contains non-numeric characters';
 }
elsif( substr($query, 0, 1) eq '0' )
 {
  $errormessage = 'requested volume number starts with leading zero';
 }
elsif( length($query) > length($voltotal) )
 {
  $errormessage = 'requested volume number is longer and therefore larger than '.$voltotal;
 }
elsif( (length($query) == length($voltotal)) and ($query gt $voltotal) )
 {
  $errormessage = 'requested volume number is of equal length but larger than '.$voltotal;
 }


# If $query is a valid volume number, use its value; otherwise show an error message:
if($errormessage eq '')
 {
  $volnow = "$query";
 }
else
 {
  print "Content-type: text/html\n";
  print "Status: 400 Bad Request\n";
  print "\n";
  print '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">'."\n";
  print "<html>\n";
  print "<head>\n";
  print "<title>error (400 Bad Request)</title>\n";
  print '<meta http-equiv="content-type" content="text/html; charset=us-ascii">'."\n";
  print "</head>\n";
  print "<body>\n";
  print "<h1>error (400 Bad Request)</h1>\n";
  print "<p>The volume which you requested does not exist.</p>\n";
  print "<p>\n";
  print "<p>Valid volume numbers nust be a number from 1 to $voltotal\n";
  print "and must be written without leading zeros\n";
  print "and without any non-digit characters.</p>\n";
  print "<p>\n";
  print "Your requested volume number was<br>\n";
  print "$query<br>\n";
  print "which caused the following problem:<br>\n";
  print "$errormessage\n";
  print "</p>\n";
  print "</body>\n";
  print "</html>\n";
  exit;
 }


# If we reach this part of the program, we know
# that $volnow is a valid volume number, and
# $voltotal is the number of the last possible
# volume number, and $versiontext indicates the
# version of the book.
# We want to produce the PDF file for volume $volnow.


#############################################################
#############################################################
##                                                         ##
## S T A R T   P R O D U C I N G   T H E   P D F   F I L E ##
##                                                         ##
#############################################################
#############################################################


# Total number of pages in the PDF file which we want to produce:
$pagenumbertotal = 405;


$nl = "\015\012";
# $nl stands for NewLine and contains the character which we use
# as line-break within the source-code of the PDF. Inentionally, we
# do not use \n which has a platform dependent length and might therefore
# result in an incorrect total line length in the final xref table.


$fs = '%PDF-1.4';
$fs .= $nl . '%'."\342\343\317\323" .$nl;
# $fs stands for FileString and should become a string which contains the entire PDF file.
# In the second line of the PDF file, we add a few non-ASCII-characters (with values above 128)
# to show certain data transfer programs that the final PDF file should be treated as a binary file.


$ic = 0;
# $ic stands for IndexCounter and is the number
# like "$ic 0 obj" when we used it the last time


$xs = '0000000000 65535 f';
# $xs stands for XrefString and should become a string which
# contains all the data for the final xref table.


%rh = ();
# %rh is the ReferenceHash


# $nn always stands for NowName of current reference


# In PDF files you can for example store some data in a block which starts with
# 123 0 obj
# and later you can for example use the data from this specific block by making a reference to
# 123 0 R
#
# So we have to count the data blocks and keep track of their numbers.
# If the last data block which we created started with "123 0 obj" then $ic has a value of 123.
#
# Often we want to make a reference to a data block which will only
# be created later during the run of this perl script, so we do not yet
# know which number it will have. So in that case we first use some
# placeholder name for example
# (*-*(exampledata)*-*) 0 R
# instead of
# 123 0 R
# When we finally create the block "exampledata" and assuming
# that this is the 123th block, we first set
# $nn="exampledata"
# then we increase $ic by one which gives 123 and we start the block with
# 123 0 obj
# Then we save
# $rh{$nn} = $ic;
# which means that we add an element to %rh which has
# the key 'exampledata' and the value 123.
# For this, we always use the sub-program nnsub which is called immediately after
# assigning the right data to $nn.
# Then, at the end of creating the PDF file we have to replace the temporary
# named references by their numbers, for example in the example mentioned
# above, we replace all occurences of (*-*(exampledata)*-*) by the number 123.
# In this case, we also add a few spaces before 123 so that
# the number with the additional spaces has the same length (number of bytes)
# as the string (*-*(exampledata)*-*) . This is necessary to make sure that
# the byte offset numbers in the final xref table remain valid.
# At the end, when we actually want to make the replacements, the
# hash %rh gives us the names which we want to replace, as well as the numbers
# by which we want to replace them.


#####################################################
#                                                   #
# S T A R T   O F   M A I N   P A R T   O F   P D F #
#                                                   #
#####################################################


$nn = 'catalog'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$fs .= $nl. '<< /Type /Catalog';
$fs .= $nl. '/Pages (*-*(pages)*-*) 0 R';
$fs .= $nl. '>>';
$fs .= $nl. 'endobj';
$fs .= $nl;


$nn = 'info'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$fs .= $nl. '<<';
$fs .= $nl. '/Title (Googolplex Written Out)';
$fs .= $nl. '/Author (Wolfgang H. Nitsche)';
$fs .= $nl. '/Creator (http://www.GoogolplexWrittenOut.com)';
$fs .= $nl. '/Producer (http://www.GoogolplexWrittenOut.com)';
$fs .= $nl. '>>';
$fs .= $nl. 'endobj';
$fs .= $nl;


$nn = 'courier'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$fs .= $nl. '<< /Type /Font';
$fs .= $nl. '/Subtype /Type1';
$fs .= $nl. '/BaseFont /Courier';
$fs .= $nl. '/Encoding /WinAnsiEncoding';
$fs .= $nl. '>>';
$fs .= $nl. 'endobj';
$fs .= $nl;


$nn = 'courierbold'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$fs .= $nl. '<< /Type /Font';
$fs .= $nl. '/Subtype /Type1';
$fs .= $nl. '/BaseFont /Courier-Bold';
$fs .= $nl. '/Encoding /WinAnsiEncoding';
$fs .= $nl. '>>';
$fs .= $nl. 'endobj';
$fs .= $nl;


$nn = 'timesroman'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$fs .= $nl. '<< /Type /Font';
$fs .= $nl. '/Subtype /Type1';
$fs .= $nl. '/BaseFont /Times-Roman';
$fs .= $nl. '/Encoding /WinAnsiEncoding';
$fs .= $nl. '>>';
$fs .= $nl. 'endobj';
$fs .= $nl;


$nn = 'timesbold'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$fs .= $nl. '<< /Type /Font';
$fs .= $nl. '/Subtype /Type1';
$fs .= $nl. '/BaseFont /Times-Bold';
$fs .= $nl. '/Encoding /WinAnsiEncoding';
$fs .= $nl. '>>';
$fs .= $nl. 'endobj';
$fs .= $nl;


$nn = 'weburi'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$fs .= $nl. '<< /S /URI';
$fs .= $nl. '/URI (http://www.GoogolplexWrittenOut.com)';
$fs .= $nl. '>>';
$fs .= $nl. 'endobj';
$fs .= $nl;


$nn = 'weblink2'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$fs .= $nl. '<< /Type /Annot';
$fs .= $nl. '/Subtype /Link';
$fs .= $nl. '/Rect [110 250 400 265]';
$fs .= $nl. '/Border [0 0 0]';
$fs .= $nl. '/A (*-*(weburi)*-*) 0 R';
$fs .= $nl. '>>';
$fs .= $nl. 'endobj';
$fs .= $nl;


$nn = 'weblink4'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$fs .= $nl. '<< /Type /Annot';
$fs .= $nl. '/Subtype /Link';
$fs .= $nl. '/Rect [150 205 450 230]';
$fs .= $nl. '/Border [0 0 0]';
$fs .= $nl. '/A (*-*(weburi)*-*) 0 R';
$fs .= $nl. '>>';
$fs .= $nl. 'endobj';
$fs .= $nl;


$nn = 'lowerlabel'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '/F2 6.4 Tf';
$stream .= $nl. '103 125 Td';
$stream .= $nl. '(Googolplex Written Out) Tj';
$stream .= $nl. '0 -6.5 Td';
$stream .= $nl. '(volume ' . $volnow . ') Tj';
$stream .= $nl. '0 -6.5 Td';
$stream .= $nl. '(of ' . $voltotal . ') Tj';
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'spiral'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
# The spiral is used for writing the volume number on the
# title pages. If the volume number is too long to write it
# in a single line (with the used font-size), then it is
# written in the form of a spiral.
# Settings for spiral:
$spiralcharacterwidth = 15;
$spirallinespacing = 40;
$spiralx0 = 200;
$spiraly0 = 410;
$spiralradius0incharacters = 9;
$spiral2pi = 2 * 3.1415926536;
# make calculations for spiral:
$spiraltext = 'volume ' . $volnow;
$spiralradius0 = $spiralradius0incharacters * $spiralcharacterwidth;
$spiralxcenter = $spiralx0 + $spiralradius0;
$spiralycenter = $spiraly0 - $spiralradius0;
$stream = '';
$stream .= 'BT' . $nl . '/F2 24 Tf';
$spiralangle = 0;
$spiralcos = 1;
$spiralsin = 0;
$spiraly = $spiraly0;
for($spiralletternumber=0; $spiralletternumber<length($spiraltext); $spiralletternumber++)
 {
  if( ($spiralletternumber < $spiralradius0incharacters) or (length($spiraltext) <= 2*$spiralradius0incharacters) )
   {
    $spiralx = $spiralx0 + $spiralletternumber * $spiralcharacterwidth;
   }
  else
   {
    $spiralradius = $spiralradius0 - $spirallinespacing * $spiralangle / $spiral2pi;
    $spiralcos = cos($spiralangle);
    $spiralsin = sin($spiralangle);
    $spiralx = $spiralxcenter + $spiralradius * sin($spiralangle);
    $spiraly = $spiralycenter + $spiralradius * cos($spiralangle);
    $spiralangle += $spiralcharacterwidth / $spiralradius;
   }
  $stream .= $nl . sprintf('%.4f %.4f %.4f %.4f %.1f %.1f ', $spiralcos, -$spiralsin, $spiralsin, $spiralcos, $spiralx, $spiraly) . 'Tm';
  $stream .= $nl . '(' . substr($spiraltext, $spiralletternumber, 1) . ') Tj';
 }
$stream .= $nl . 'ET';
#--
&streamsub;


$nn = 'outsidetitle'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '/F2 36 Tf';
$stream .= $nl. '200 600 Td';
$stream .= $nl. '(Googolplex) Tj';
$stream .= $nl. '0 -36 Td';
$stream .= $nl. '(Written) Tj';
$stream .= $nl. '0 -36 Td';
$stream .= $nl. '(Out) Tj';
$stream .= $nl. '0 -72 Td';
$stream .= $nl. '/F1 24 Tf';
$stream .= $nl. '(Wolfgang H. Nitsche) Tj';
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'leftblank'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '/F3 16 Tf';
$stream .= $nl. '120 600 Td';
$stream .= $nl. '((This page is intentionally left blank.)) Tj';
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'biblioinfo'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '120 330 Td';
$stream .= $nl. '/F4 10 Tf';
$stream .= $nl. '(Author: ) Tj';
$stream .= $nl. '/F3 10 Tf';
$stream .= $nl. '(Nitsche, Wolfgang H.) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '/F4 10 Tf';
$stream .= $nl. '(Title: ) Tj';
$stream .= $nl. '/F3 10 Tf';
$stream .= $nl. '(Googolplex Written Out) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '/F4 10 Tf';
$stream .= $nl. '(Date of publication: ) Tj';
$stream .= $nl. '/F3 10 Tf';
$stream .= $nl. '(August 2013) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '/F4 10 Tf';
$stream .= $nl. '(Publisher: ) Tj';
$stream .= $nl. '/F3 10 Tf';
$stream .= $nl. '(Nitsche) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '/F4 10 Tf';
$stream .= $nl. '(Place of publication: ) Tj';
$stream .= $nl. '/F3 10 Tf';
$stream .= $nl. '(Stanford, California, U.S.A.) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '/F4 10 Tf';
$stream .= $nl. '(Web: ) Tj';
$stream .= $nl. '/F3 10 Tf';
$stream .= $nl. '(http://www.GoogolplexWrittenOut.com) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '/F4 10 Tf';
$stream .= $nl. '(ISBN ) Tj';
$stream .= $nl. '/F3 10 Tf';
$stream .= $nl. '(978-0-9900072-0-3 (multivolume set of PDF e-books)) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '/F4 10 Tf';
$stream .= $nl. '(ISBN ) Tj';
$stream .= $nl. '/F3 10 Tf';
$stream .= $nl. '(978-0-9900072-1-0 (multivolume set of soft-cover books)) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '/F3 10 Tf';
$stream .= $nl. '(\(These ISBNs refer to the entire multivolume set of books. No ISBNs have been) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '(assigned to all the individual volumes, since the total number of volumes exceeds) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '(the number of available ISBNs by many orders of magnitude.\)) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '/F3 5 Tf';
$stream .= $nl. '(' . $versiontext . ') Tj';
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'insidetitle'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '/F4 36 Tf';
$stream .= $nl. '200 650 Td';
$stream .= $nl. '(Googolplex) Tj';
$stream .= $nl. '0 -36 Td';
$stream .= $nl. '(Written) Tj';
$stream .= $nl. '0 -36 Td';
$stream .= $nl. '(Out) Tj';
$stream .= $nl. '0 -71 Td';
$stream .= $nl. '/F3 20 Tf';
$stream .= $nl. '(Wolfgang H. Nitsche) Tj';
$stream .= $nl. '0 -30 Td';
$stream .= $nl. '/F3 15 Tf';
$stream .= $nl. '(Stanford University) Tj';
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'introduction'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '/F4 24 Tf';
$stream .= $nl. '125 650 Td';
$stream .= $nl. '(Foreword) Tj';
$stream .= $nl. '0 -36 Td';
$stream .= $nl. '/F3 12 Tf';
$stream .= $nl. '0.8 Tc';
$stream .= $nl. '(In 1940, the mathematician Edward Kasner published the book) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '0.11 Tc';
$stream .= $nl. '("Mathematics and the Imagination", in which he popularized the words) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '0.27 Tc';
$stream .= $nl. '(googol and googolplex which his nephew suggested as names for big) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '0 Tc';
$stream .= $nl. '(numbers.) Tj';
$stream .= $nl. '0 -30 Td';
$stream .= $nl. '(The number googol has been defined as 1 followed by a hundred zeros:) Tj';
$stream .= $nl. '30 -18 Td';
$stream .= $nl. '(googol = 10) Tj';
$stream .= $nl. '60 6 Td';
$stream .= $nl. '/F3 8 Tf';
$stream .= $nl. '(100) Tj';
$stream .= $nl. '/F3 12 Tf';
$stream .= $nl. '17 -6 Td';
$stream .= $nl. '( = 1' . ('0' x 34) . ') Tj';
$stream .= $nl. '-77 -15 Td';
$stream .= $nl. '(' . ('0' x 50) . ') Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '(' . ('0' x 16) . '.) Tj';
$stream .= $nl. '-30 -30 Td';
$stream .= $nl. '0.11 Tc';
$stream .= $nl. '(The much larger number googolplex has been defined as 1 followed by) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '0 Tc';
$stream .= $nl. '(a googol zeros. While this number can easily be written as) Tj';
$stream .= $nl. '30 -18 Td';
$stream .= $nl. '(googolplex = 10) Tj';
$stream .= $nl. '82 6 Td';
$stream .= $nl. '/F3 8 Tf';
$stream .= $nl. '(googol) Tj';
$stream .= $nl. '/F3 12 Tf';
$stream .= $nl. '25 -6 Td';
$stream .= $nl. '( = 10) Tj';
$stream .= $nl. '27 6 Td';
$stream .= $nl. '/F3 8 Tf';
$stream .= $nl. '(\(10) Tj';
$stream .= $nl. '12 4 Td';
$stream .= $nl. '(100) Tj';
$stream .= $nl. '15 -4 Td';
$stream .= $nl. '(\)) Tj';
$stream .= $nl. '/F3 12 Tf';
$stream .= $nl. '-191 -21 Td';
$stream .= $nl. '(using the exponential notation, it has often been claimed that the number) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '(googolplex is so large that it can never be written out in full.) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '0.11 Tc';
$stream .= $nl. '(However in this "Googolplex Written Out" multivolume set of books, I) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '0.01 Tc';
$stream .= $nl. '(am doing just that. It consists of 1' . ('0' x 31) . ') Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '0.03 Tc';
$stream .= $nl. '(' . ('0' x 58) . ') Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '0.02 Tc';
$stream .= $nl. '(' . ('0' x 5) . ' volumes, and each volume contains 1000000 zeros of the number) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '0.38 Tc';
$stream .= $nl. '(googolplex. The first volume also contains the initial digit one with) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '0 Tc';
$stream .= $nl. '(which googolplex starts.) Tj';
$stream .= $nl. '100 -60 Td';
$stream .= $nl. '(Wolfgang H. Nitsche) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '(August 2013) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. '(www.GoogolplexWrittenOut.com) Tj';
$stream .= $nl. '0 -15 Td';
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'manyzeros'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '/F1 12.3 Tf';
$stream .= $nl. '100 740 Td';
$stream .= $nl. '0 -11.8 Td';
for($linenumber=2; $linenumber<=50; $linenumber++)
 {
  $stream .= $nl. '0 -11.8 Td';
  $stream .= $nl. '(0000000000 0000000000 0000000000 0000000000 0000000000) Tj';
 }
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'topzeros'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '/F1 12.3 Tf';
$stream .= $nl. '100 740 Td';
$stream .= $nl. '0 -11.8 Td';
$stream .= $nl. '(0000000000 0000000000 0000000000 0000000000 0000000000) Tj';
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'topfirst'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '/F1 12.3 Tf';
$stream .= $nl. '100 740 Td';
$stream .= $nl. '0 -11.8 Td';
$stream .= $nl. '( 1 googolplex   =   1 0000000000 0000000000 0000000000) Tj';
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'topcontinue'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '/F2 8 Tf';
$stream .= $nl. '100 740 Td';
$stream .= $nl. '0 -11.8 Td';
$stream .= $nl. '(continuation from previous volume) Tj';
$stream .= $nl. 'ET';
$stream .= $nl. 'BT';
$stream .= $nl. '/F1 12.3 Tf';
$stream .= $nl. '100 740 Td';
$stream .= $nl. '0 -11.8 Td';
$stream .= $nl. '(                      0000000000 0000000000 0000000000) Tj';
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'bottomcontinue'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '/F1 12.3 Tf';
$stream .= $nl. '100 138 Td';
$stream .= $nl. '(0000000000 0000000000) Tj';
$stream .= $nl. 'ET';
$stream .= $nl. 'BT';
$stream .= $nl. '/F2 8 Tf';
$stream .= $nl. '270 138 Td';
$stream .= $nl. '(continued in next volume) Tj';
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'bottomlast'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      'BT';
$stream .= $nl. '/F1 12.3 Tf';
$stream .= $nl. '100 138 Td';
$stream .= $nl. '(0000000000 0000000000) Tj';
$stream .= $nl. 'ET';
$stream .= $nl. 'BT';
$stream .= $nl. '/F2 8 Tf';
$stream .= $nl. '280 138 Td';
$stream .= $nl. '(THE END) Tj';
$stream .= $nl. 'ET';
#--
&streamsub;


$nn = 'box'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$stream = '';
$stream .=      '100 100 m';
$stream .= $nl. '500 100 l';
$stream .= $nl. '500 740 l';
$stream .= $nl. '100 740 l';
$stream .= $nl. 'h';
$stream .= $nl. 'S';
$stream .= $nl. '100 133 m';
$stream .= $nl. '500 133 l';
$stream .= $nl. 'S';
#--
&streamsub;


# create the data blocks which we need to show the page numbers for each of the pages: # # # # # # # # # # # # # # # # # # # #
for($pagenumbernow=1; $pagenumbernow<=$pagenumbertotal; $pagenumbernow++)
 {
  $nn = 'pagelabel'.$pagenumbernow; # # # # # # # # # # # # # # # # # # # #
  &nnsub;
  #
  $nowpagenumbertext = 'page ' . $pagenumbernow;
  $nowleftspace = 300 - 0.5 * (400/54) * length($nowpagenumbertext);
  $stream = '';
  $stream .=      'BT';
  $stream .= $nl. '/F2 12.3 Tf';
  $stream .= $nl. sprintf('%d', $nowleftspace) . ' 103 Td';
  $stream .= $nl. '(' . $nowpagenumbertext . ') Tj';
  $stream .= $nl. 'ET';
  #--
  &streamsub;
 }


$nn = 'pages'; # # # # # # # # # # # # # # # # # # # #
&nnsub;
#
$fs .= $nl. '<< /Type /Pages';
$fs .= $nl. '/MediaBox [0 0 595.275 841.889]';
$fs .= $nl. '/Resources << /ProcSet [/PDF /Text]';
$fs .= $nl. '/Font <<';
$fs .= $nl. '/F1 (*-*(courier)*-*) 0 R';
$fs .= $nl. '/F2 (*-*(courierbold)*-*) 0 R';
$fs .= $nl. '/F3 (*-*(timesroman)*-*) 0 R';
$fs .= $nl. '/F4 (*-*(timesbold)*-*) 0 R';
$fs .= $nl. '>>';
$fs .= $nl. '>>';
$fs .= $nl. '/Kids [';
for($pagenumbernow=1; $pagenumbernow<=$pagenumbertotal; $pagenumbernow++)
 {
  $fs .= $nl. '(*-*(page' . $pagenumbernow . ')*-*) 0 R';
 }
$fs .= $nl. ']';
$fs .= $nl. '/Count ' . $pagenumbertotal;
$fs .= $nl. '>>';
$fs .= $nl. 'endobj';
$fs .= $nl;


# create the data blocks which correspond to the individual pages: # # # # # # # # # # # # # # # # # # # #
for($pagenumbernow=1; $pagenumbernow<=$pagenumbertotal; $pagenumbernow++)
 {
  $nn = 'page'.$pagenumbernow; # # # # # # # # # # # # # # # # # # # #
  &nnsub;
  #
  $fs .= $nl. '<< /Type /Page';
  $fs .= $nl. '/Parent (*-*(pages)*-*) 0 R';
  $fs .= $nl. '/Contents [';
  $fs .= $nl. '(*-*(box)*-*) 0 R';
  if($pagenumbernow == 1)
   {
    $fs .= $nl. '(*-*(outsidetitle)*-*) 0 R';
    $fs .= $nl. '(*-*(spiral)*-*) 0 R';
   }
  if($pagenumbernow == 2)
   {
    $fs .= $nl. '(*-*(biblioinfo)*-*) 0 R';
   }
  if($pagenumbernow == 3)
   {
    $fs .= $nl. '(*-*(insidetitle)*-*) 0 R';
    $fs .= $nl. '(*-*(spiral)*-*) 0 R';
   }
  if($pagenumbernow == 4)
   {
    $fs .= $nl. '(*-*(introduction)*-*) 0 R';
   }
  if($pagenumbernow == 5)
   {
    if("$volnow" eq "1")
     {
      $fs .= $nl. '(*-*(topfirst)*-*) 0 R';
     }
    else
     {
      $fs .= $nl. '(*-*(topcontinue)*-*) 0 R';
     }
   }
  if( ($pagenumbernow >= 6) and ($pagenumbernow <= 404) )
   {
    $fs .= $nl. '(*-*(topzeros)*-*) 0 R';
   }
  if( ($pagenumbernow >= 5) and ($pagenumbernow <= 404) )
   {
    $fs .= $nl. '(*-*(manyzeros)*-*) 0 R';
   }
  if($pagenumbernow == 404)
   {
    if("$volnow" eq "$voltotal")
     {
      $fs .= $nl. '(*-*(bottomlast)*-*) 0 R';
     }
    else
     {
      $fs .= $nl. '(*-*(bottomcontinue)*-*) 0 R';
     }
   }
  if($pagenumbernow == 405)
   {
    $fs .= $nl. '(*-*(leftblank)*-*) 0 R';
   }
  $fs .= $nl. '(*-*(lowerlabel)*-*) 0 R';
  $fs .= $nl. '(*-*(pagelabel' . $pagenumbernow . ')*-*) 0 R';
  $fs .= $nl. ']';
  if($pagenumbernow == 2)
   {
    $fs .= $nl. '/Annots [ (*-*(weblink2)*-*) 0 R ]';
   }
  if($pagenumbernow == 4)
   {
    $fs .= $nl. '/Annots [ (*-*(weblink4)*-*) 0 R ]';
   }
  $fs .= $nl. '>>';
  $fs .= $nl. 'endobj';
  $fs .= $nl;
 }


###################################################
#                                                 #
# S T A R T   B O T T O M   O F   P D F   F I L E #
#                                                 #
###################################################


# add the bottom stuff (like xref table and trailer) to the PDF file:
$fs .= $nl;
$startxref = length($fs);
$fs .=  'xref';
##
$fs .= $nl. "0 " . (1 + $ic);
$fs .= $nl. $xs;
$fs .= $nl;
$fs .= $nl. 'trailer';
$fs .= $nl. '<<';
$fs .= $nl. '/Size ' . (1 + $ic);
$fs .= $nl. '/Root (*-*(catalog)*-*) 0 R';
$fs .= $nl. '/Info (*-*(info)*-*) 0 R';
$fs .= $nl. '>>';
$fs .= $nl. 'startxref';
$fs .= $nl. $startxref;
$fs .= $nl. '%%EOF';

# replace the placeholder words like (*-*(exampledata)*-*) by the respective numbers:
for (keys %rh)
 {
  $nowkey = $_;
  $referenceasname = '(*-*(' . $nowkey . ')*-*)';
  $referencewantformat = '% ' . length($referenceasname) . 's';
  $referenceasname =~ s/([^a-zA-Z0-9_])/\\$1/g;
  $referenceasnumber = sprintf($referencewantformat, $rh{$nowkey});
  $fs =~ s/$referenceasname/$referenceasnumber/g;
 }


#############################################################
#############################################################
##                                                         ##
## N O W   T H E   P D F   F I L E   I S   P R O D U C E D ##
## A N D   W E   W A N T   T O   S H O W   I T .           ##
##                                                         ##
#############################################################
#############################################################


print "Content-type: application/pdf\n";
print 'Link: <http://www.GoogolplexWrittenOut.com/volume'.$volnow.'.pdf>; rel="canonical"'."\n";
print "\n";
print $fs;
exit;


################################################
################################################
##                                            ##
## E N D   O F   M A I N   P R O G R A M      ##
## S T A R T   O F   S U B - P R O G R A M S  ##
##                                            ##
################################################
################################################


# This is the sup-program which we always call immediately
# after assigning a new value to $nn. It will then add the
# corresponding data of the form (after final replacement)
# 123 0 obj
# to the file string $fs,
# and also the line of the form
# 0000032323 00000 n
# to $xs for the xref table.
sub nnsub
 {
  $fs .= $nl;
  $xs .= $nl. sprintf('%010s', length($fs)) .' 00000 n';
  $fs .=  ++$ic ." 0 obj";
  $fs .= $nl. '% ' . $nn . ' = ' . "(*-*($nn)*-*)" .' = ' . $ic;
  $fs .= $nl. '% --------------------';
  $rh{$nn} = $ic;
  $nn = '';
 }


# This is the sub-program which we call whenever $stream
# contains the data which we want to add now to
# to the file string $fs
# as a stream.
# Usually the $stream which we give to this sub-program
# will neither start nor end with a line-break, and this
# sub-program will add all required additional linebreaks.
sub streamsub
 {
  $stream .= $nl;
  $fs .= $nl. '<< /Length ' . length($stream) . ' >>';
  $fs .= $nl. 'stream';
  $fs .= $nl. $stream;
  $fs .=      'endstream';
  $fs .= $nl. 'endobj';
  $fs .= $nl;
  $stream = '';
 }


#################################
#################################
##                             ##
## E N D   O F   P R O G R A M ##
##                             ##
#################################
#################################