pkgbuilds/ips.pl/ips.txt

   1 #!/usr/bin/perl
   2
   3 # ips.pl
   4 # version 0.01
   5 #
   6 # This is a quick hack to apply IPS patches. It is distributed under
   7 # the terms of the GNU General Public License.
   8
   9 if (@ARGV != 2)
  10 {
  11 print STDERR <<EOF;
  12 Usage:
  13
  14 $0 datafile ipsfile
  15
  16 There are no options. Your original datafile is modified.
  17 EOF
  18 exit;
  19 }
  20
  21 open PAT, "$ARGV[1]" or die "Can't open $ARGV[1]";
  22 open DAT, "+<$ARGV[0]" or die "Can't open $ARGV[0]";
  23
  24 read PAT, $data, 5;
  25 die "Bad magic bytes in $ARGV[1]" if $data ne "PATCH";
  26 while(1)
  27 {
  28 read PAT, $data, 3 or die "Read error";
  29 if ($data eq "EOF")
  30 {
  31 print STDERR "Done!n";
  32 exit;
  33 }
  34 # This is ugly, but unpack doesn't have anything that's
  35 # very helpful for THREE-byte numbers.
  36 $address = ord(substr($data,0,1))*256*256 +
  37 ord(substr($data,1,1))*256 +
  38 ord(substr($data,2,1));
  39 print STDERR "At address $address, ";
  40 seek DAT, $address, SEEK_SET or die "Failed seek";
  41
  42 read PAT, $data, 2 or die "Read error";
  43 $length = ord(substr($data,0,1))*256 + ord(substr($data,1,1));
  44 if ($length)
  45 {
  46 print STDERR "Writing $length bytes, ";
  47 read(PAT, $data, $length) == $length or die "Read error";
  48 print DAT $data;
  49 }
  50 else # RLE mode
  51 {
  52 read PAT, $data, 2 or die "Read error";
  53 $length = ord(substr($data,0,1))*256 + ord(substr($data,1,1));
  54 print STDERR "Writing $length bytes of RLE, ";
  55 read PAT, $byte, 1 or die "Read error";
  56 print DAT ($byte)x$length;
  57 }
  58 print STDERR "donen";
  59 }