eval '(exit $?0)' && eval 'exec perl -S $0 ${1+"$@"}' && eval 'exec perl -S $0 $argv:q'
  if 0;
use strict;
$^W=1; # turn warning on
#
# adjust_checksum.pl
#
# Copyright (C) 2006 by Heiko Oberdiek <oberdiek@uni-freiburg.de>
#
# This work may be distributed and/or modified under the
# conditions of the LaTeX Project Public License, either
# version 1.3 of this license or (at your option) any later
# version. The latest version of this license is in
#    http://www.latex-project.org/lppl.txt
# and version 1.3 or later is part of all distributions of
# LaTeX version 2003/12/01 or later.
#
# This work has the LPPL maintenance status "maintained".
#
# This Current Maintainer of this work is Heiko Oberdiek.
#
# This work consists of this file.
#
# This file "adjust_checksum.pl" may be renamed to "adjust_checksum"
# for installation purposes.
#
my $file        = "adjust_checksum.pl";
my $program     = uc($&) if $file =~ /^\w+/;
my $version     = "1.1";
my $date        = "2006/02/12";
my $author      = "Heiko Oberdiek";
my $copyright   = "Copyright (c) 2002, 2006 by $author.";
#
# Reqirements: Perl5, Linux
# History:
#   2002/03/15 v1.0: First release.
#   2006/02/12 v1.1: Fix for \Checksum{0}.
#

my $tempdir = "tmp_\L$program\E_$$";

### program identification
my $title = "$program $version, $date - $copyright\n";

my $usage = <<"END_OF_USAGE";
${title}Syntax: \L$program\E <file.dtx>
Function: Correction of "\\Checksum{...}" entry in <file.dtx>.
END_OF_USAGE

### error strings
my $Error = "!!! Error:"; # error prefix

### parse command line arguments
@ARGV == 1 or die $usage;
my $dtxfile = $ARGV[0];

print $title;

### check dtx file
-f $dtxfile or die "$Error File not found: '$dtxfile'!\n";

### signals
$SIG{__DIE__} = \&clean;
$SIG{'HUP'}   = \&clean;
$SIG{'INT'}   = \&clean;
$SIG{'QUIT'}  = \&clean;
$SIG{'TERM'}  = \&clean;

### make temp dir
mkdir $tempdir;
-d $tempdir or die "$Error Cannot create directory '$tempdir'!\n";

### copy dtx file
my $tempdtxfile = $dtxfile;
$tempdtxfile =~ s/.*\///;
my $latexfile = $tempdtxfile;
$tempdtxfile = $tempdir . "/" . $tempdtxfile;

system("cp $dtxfile $tempdtxfile");
-f $tempdtxfile or die "$Error Cannot copy dtx file!\n";

### run latex
print "*** Running LaTeX ...\n";
system("(cd $tempdir; latex --interaction=batchmode $latexfile)");

my $logfile = $tempdtxfile;
$logfile =~ s/\.[^\.]+$//;
$logfile .= ".log";
-f $logfile or die "$Error Cannot find log file '$logfile'!\n";

### parse log file for CheckSum
print "*** Looking for checksum statement ...\n";
my $found = 0;
my $changed = 0;
my $old = 0;
my $new = 0;
open(LOG, $logfile) or die "$Error Cannot open log file '$logfile'!\n";
while (<LOG>) {
  if (/\* Checksum passed \*/) {
    $found = 1;
    $changed = 0;
    print "==> Checksum passed.\n";
    last;
  }
  if (/Checksum not passed \((\d+)<>(\d+)\)/) {
    $found = 1;
    $changed = 1;
    $old = $1;
    $new = $2;
    last;
  }
  if (/The checksum should be (\d+)!/) {
    $found = 1;
    $changed = 1;
    $old = 0;
    $new = $1;
    last;
  }
}
close(LOG);

$found or die "$Error Checksum statement not found in log file!\n";

if ($changed) {
  print "==> Checksum not passed ($old<>$new).\n";

  ### write changed dtx file
  print "*** Fixing Checksum ...\n";
  my $fixed = 0;
  open(IN, $tempdtxfile) or die "$Error Cannot open '$tempdtxfile'!\n";
  open(OUT, ">$dtxfile") or die "$Error Cannot write '$dtxfile'!\n";
  while (<IN>) {
    if (s/\\CheckSum\{\d+\}/\\CheckSum{$new}/) {
      $fixed++;
      print "==> Checksum fixed:\n$_";
    }
    print OUT;
  }
  close(IN);
  close(OUT);

  $fixed > 0 or
      die "$Error: \"\\CheckSum{...}\" not found!\n";
  $fixed == 1 or
      die "$Error: More than one \"\\CheckSum\" command found!\n";
}

### cleaning
sub clean {
  if (-d $tempdir) {
    unlink glob("$tempdir/*");
    rmdir $tempdir;
  }
}

clean();

print "*** Ready.\n";

__END__