--- loncom/interface/printout.pl	2006/04/24 21:30:06	1.98
+++ loncom/interface/printout.pl	2006/06/12 18:05:02	1.101
@@ -161,7 +161,8 @@ END
 }
  &Apache::lonlocal::get_language_handle();
  &Apache::loncommon::content_type(undef,'text/html');
- print(&Apache::loncommon::start_page('Creating PDF'));
+
+  print(&Apache::loncommon::start_page('Creating PDF'));
 
   my $identifier = $ENV{'QUERY_STRING'};
   my $texfile = $env{'cgi.'.$identifier.'.file'};
@@ -475,6 +476,7 @@ foreach $texfile (@texfile) {
 			     "for $status_statement now Converting to PS",
 			     \%prog_state,$new_name_file);
 	  if (-e $new_name_file) {
+	      &repaginate_postscript($new_name_file);
 	      print "<h1>PDF output file (see link below)</h1>\n";
 	      $new_name_file =~ m/^(.*)\./;
 	      my $ps_file = my $tempo_file = $1.'temporar.ps';
@@ -549,6 +551,7 @@ foreach $texfile (@texfile) {
 			     "for $status_statement now Converting to PS",
 			     \%prog_state,$new_name_file);
 	  if (-e $new_name_file) {
+	      &repaginate_postscript($new_name_file);
 	      print "<br />";
 	      $new_name_file =~ m/^(.*)\./;
 	      my $ps_file = my $tempo_file = $1.'temporar.ps';
@@ -638,6 +641,7 @@ sub busy_wait_command {
     
     $SIG{CHLD} = \&REAPER;
     $done=0;
+    print("<p> Doing : <tt>$command</tt>");
     my $pid=open(CMD,"$command |");
     if ($advanced_role) {
 	&Apache::lonhtmlcommon::Update_PrgWin('',$progress_win,$message);
@@ -657,7 +661,129 @@ sub busy_wait_command {
     $SIG{CHLD}='IGNORE';
     close(CMD);
 }
+    print("<p> End</p>");
 
+#  Repagninate a postscript file.
+#  What we need to do:
+#   - Count the number of pages in each student.
+#   - Add pages between each student so that each student's output is
+#     the maximum number of pages.
+#   
+sub repaginate_postscript {
+
+    # We will try to do this in 2 passes through the postscript since
+    # the postscript is potentially large, to do 2 passes, the first pass
+    # must be able to calculate the total number of document pages so that
+    # at the beginning of the second pass we already know how to replace
+    #  %%Pages:
+
+    #  Figure out
+    #    1. Number of pages in the document
+    #    2. Maximum number of pages in a student
+    #    3. Number of pages in each student.
+
+    my ($postscript_filename) = @_;
+    open(PSFILE, "<$postscript_filename");
+    my $line;
+    my $total_pages;		# Total pages in document.
+    my $seen_pages        = 0;	# There are several %%Pages only the first is useful
+    my $student_number    = 0;	# Index of student we're working on.
+    my @pages_in_student;	# For each student his/her initial page count.
+    my $max_pages = 0;		# Pages in 'longest' student.
+    while ($line = <PSFILE>) {
+	my $page_number = 0;
+	
+	# Check for total pages (%%Pages:)
+
+	if (($line =~ /^%%Pages:/) && (!$seen_pages)) {
+	    my @pageinfo = split(/ /,$line);
+	    $total_pages = $pageinfo[1];
+	    $seen_pages  = 1;
+	}
+	#  Check for %%Page: n m  $page_number will be the
+	#  biggest of these until we see an endofstudent.
+	#  Note that minipages generate spurious %Page: 1 1's so
+	#  we only are looking for the largest n (n is page number at the
+	#  bottom of the page, m the page number within the document.
+	#
+	if ($line =~ /^%%Page:/) {
+	    my @pageinfo = split(/ /, $line);
+	    if ($page_number < $pageinfo[1]) {
+		$page_number = $pageinfo[1];
+	    }
+	}
+	#  ENDOFSTUDENTSTAMP - save the page_number, reset and, if necessary
+	#                      udpate max_pages.
+	#
+	if ($line =~ /ENDOFSTUDENTSTAMP/) {
+	    $pages_in_student[$student_number] = $page_number;
+	    $student_number++;
+
+	    if ($page_number > $max_pages) {
+		$max_pages = $page_number;
+	    }
+	    $page_number = 0;
+	 
+	}
 
+	
+    }
+    close(PSFILE);
+    
+    #   Figure out how many total pages we need to add and adjust the
+    #   $total_pages accordingly:
+    #
+    my $add_pages  = 0;
+    for (my $i =0; $i < $student_number; $i++) {
+	$add_pages += ($max_pages - $pages_in_student[$i]);
+    }    
+    #  If we don't need to add any pages, we're done!
+    #  You  might think that we don't need to do anything if 
+    #  there are no pages to add, however we still need to at least strip out
+    #   the ENDOFSTUDENTSTAMP stamps...as they are not postscript comments!!
 
+  
+    #  Now pass 2; we're going to write the new. ps file:
+    #  -  Modify its first %%Pages: line so that it has the new correct number of
+    #     pages
+    #  -  For each student, insert as many blank pages as needed (and
+    #     associated structured comments) to expand a  student out to
+    #     max_pages pages.
+    #  -  Remove the ENDOFSTUDENTSTAMP lines.
+    #
+
+    $total_pages += $add_pages;
+    $student_number = 0;
+ 
+    open(PSFILE, "<$postscript_filename");
+    open(PSOFILE,">$postscript_filename"."repaginating"); # unique if original fname is.
+    $seen_pages = 0;		# Reset seen %%Pages flag...
+    while ($line = <PSFILE>) {
+	if (($line =~ /^%%Pages:/) && (!$seen_pages)) {
+	    $line = "%%Pages: $total_pages\n";
+	    $seen_pages = 1;
+	}
+	if ($line =~ /ENDOFSTUDENTSTAMP/) {
+	    $add_pages = ($max_pages - $pages_in_student[$student_number]);
+	    $line = "\n";
+	    my $last_student_page = $pages_in_student[$student_number];
+	    my $last_total_page   = $student_number*$max_pages + $last_student_page;
+	    while ($add_pages) {
+		$line .= "%Page: $last_student_page $last_total_page\n";
+		my $bop = $last_total_page-1;
+		$line .= "TeXDict begin $last_student_page $bop bop eop end\n";
+		$last_student_page++;
+		$last_total_page++;
+		$add_pages--;
+	    }
+	    $student_number++;
+	}
+	print PSOFILE ($line);
+    }
+    close(PSOFILE);
+    close(PSFILE);
+
+    rename($postscript_filename."repaginating", $postscript_filename);
+
+}