#!/usr/bin/perl -w
#
# usojpg.pl version 0.03 - usojpeg-encryption/decryption program
# copyright (c) 2003 hanawa <y@hnw.jp>

$VERSION="0.03";

use Getopt::Long;

%opt = (
  'help|h'             => \$opt_help,
  'version|v'          => \$opt_version,
  );

Getopt::Long::Configure("bundling", "no_ignore_case");

&GetOptions(%opt);

if ($opt_help) {
  &show_help();
} elsif ($opt_version) {
  &show_version();
}

unless (@ARGV) {
  &show_help();
} else {
  binmode(STDOUT);
  foreach (@ARGV) {
    my($str,$head);
    $size = -s $_;
    if (! -f _) {
      print STDERR "$_ is not a regular file. Ignored.\n";
      next;
    }
    if ($size < 32) {
      print STDERR "$_ is too small. Ignored.\n";
      next;
    }
    open(FH, $_) or next;
    binmode(FH);    
    read(FH, $head, 32);
    if ($head =~ /\xff\xd8\xff\xe0\x00\x10JFIF.{10}2\.reVGEPJOSU/) {
      read(FH, $str, $size-32);
      print scalar(reverse($str));
    } elsif ($head =~ /\xff\xd8\xff\xe0\x00\x10JFIF.{10}USOJPEGVer\.2/) {
      read(FH, $str, $size-32);
      print scalar($str);
    } else {
      print STDERR "$_ is not usojpeg file. Ignored.\n";
    }
    close(FH);
  }
}

sub show_help {
  print STDERR "usage: $0 [file]... \n";
  exit;
}
sub show_version {
  print STDERR "usojpeg.pl version $VERSION\n";
  print STDERR "copyright (c) 2003 hanawa <y\@hnw.jp>\n";
  exit;
}