                  MakePatch 1.0 -=- by Marcus Grber 1992
                         mgroeber@compuserve.com

MakePatch (i.e. MAKEPAT.EXE) can be use to create patch files for use
with OS/2's standard patch facility: The PATCH command can be used to
change byte values in a file, either interactively (which is documented in
the online help), or using a patchfile (which isn't):

To use an automatic patch file, PATCH must be called using

  PATCH /a patchfile

The patchfile must contain the name of the file to be patched and a list
of the patches to apply to that file. Optionally, a file may also contain
verification info to make sure that the right version is patched.

MAKEPAT compares two version of a file (the old and the new one) and writes
the patchfile necessary to transform the old version into the new one to
stdout. Therefore, you can redirect the patch instructions to a data file
(using ">patchfile"), or just look at them, as a quick-and-dirty compare.

Typing just MAKEPAT will give you a description of the program usage.

Example: MAKEPAT file.old file.exe >old2new.pat

Note that you cannot create patch files for two files of different length
or with a large number of differences - the first is a limitiation of OS/2's
patch command, not only of MAKEPAT.

The filename is hardcoded in the patchfile (FILE line, using the name of the 
"new file" you specified on the command line). When applying the patch,
this file must be found by PATCH, so it's best not to specify any path and
change to the directory with the file to be patched before calling PATCH.

The patches generated contain verification data (lines starting with VER) to 
check that the locations to be patched hold the correct "old" values. If 
verification fails, the changes in the following lines (starting with CHA) 
are not applied.

Multiple patches can be put into one file (using >> to append to an existing
patch file). Verification is then done separately for each file.
