🚀 go-pugleaf

In article <1992Jul30.152020.8261@menudo.uh.edu> cosc16to@menudo.uh.edu (Andy Hakim) writes:
>In article <1992Jul29.125540.7401@hou.amoco.com> jim@n5ial.chi.il.us writes:
>>
>>I've seen lots of programs (usually shareware types) that allow you to
>>make configuration changes, insert registration info, etc., directly into
>>the compiled exe file.  

>To figure out the offset:  (DEFAULT_OFFSET in example)  compile the
>program, then use a program such as LIST to scan for a sequence of
>matching bytes ( 100 118 138 )  The HEX DUMP mode of LIST is handy.
>Next, go back to your source file, and update the correct offset.
>An alternative way to figure out the offset is to use info from .map files.

Those are both quite dangerous.  Plenty of people use PKLITE or LZEXE or
another .EXE compressor to modify .EXE files; if you blindly go reading
and writing at a specific location, you'll mess up badly.  A better
solution is to append the data to the .EXE file; the unbuggy compressors will
think it's an overlay, and leave it alone, or refuse to work.  You
should also be sure to put a signature in the record, so you can double
check that whatever calculation you end up with is correct.

If you want to be really nice to your users, you'll give them the option
of reading the config info from a config file, too.  That way it's easy
to maintain multiple different configurations.

A nice way to do this (both ways) is using a Turbo Vision resource file,
if you're using Borland's Pascal or C++.  It's very easy to use a config
file if present or your .EXE if not, and all the signature checking is
built in.

Duncan Murdoch
dmurdoch@mast.queensu.ca