The Essential Home & Business Collection/The Essential Home & Business Collection.iso/23/1/6/LZEXE91.EXE/LZESHELL.DOC

Text File | 1990-03-14 | 6KB | 114 lines

                                 LZESHELL.EXE
                                  Version 1.0

     ┌───────────────────────────────────────────────────────────────────┐
     │  An English language shell program for running Fabrice Bellard's  │
     │   LZEXE file compression utility for EXE files.  Also runs his    │
     │      UPACKEXE program for unpacking EXE files that have been      │
     │     processed with Microsoft's EXEPACK utility, so LZEXE can      │
     │                  achieve maximum compression.                     │
     └───────────────────────────────────────────────────────────────────┘



AUTHOR:  Pete Petrakis, CIS 76555,1175


DESCRIPTION

This program is designed to work only with version 0.91 of LZEXE, a utility
that can compress EXE files substantially while leaving them executable.  The
compressions LZEXE achieves are usually in the range of 30 to 40 percent,
although they are often higher than that.  Programs compressed with LZEXE
decompress themselves when they are run.  The decompression time is negligible.
LZEXE was written by Fabrice Bellard, of Grabels, France and is still under
development.

  Version 0.91 of LZEXE overcomes version 0.90's problem of excessive load
memory size for compressed files.  The compressed files now take about the same
amount of memory to load as they did before compression.  For this reason my
previous shell program LZEFIX, which ran Microsoft's EXEMOD header utility
to reduce the excessive load sizes created by version 0.90, should not be used
with version 0.91.  It isn't needed.  In fact it could cause problems
(including having to reboot your system) if you try to use it with this newer
version of LZEXE.  Accordingly, LZESHELL makes no adjustment to the headers of
compressed EXE files.

  Unlike the previous version of LZEXE, version 0.91 prompts, in French, for
user input, depending on what it finds out about the file you have asked it
to compress.  LZESHELL translates the prompts into English (the translation
is not literal).  That's not all it does, however.

  LZESHELL also automates the use of two of Bellard's utilities:  LZEXE v0.91,
of course, and a new program he has written called UPACKEXE v1.00.  UPACKEXE
unpacks EXE files that have been compressed with Microsoft's EXEPACK utility.
Unpacking such files allows LZEXE to do an even better compression job.

  Version 0.91 of LZEXE can detect files that have been EXEPACKed.  When it
does, it tells you so and asks whether it should continue the compression or
quit so you can run UPACKEXE first.  In that situation, you would normally end
up running two programs manually.  When you use LZESHELL, however, you
don't have to quit if you want to use UPACKEXE.  LZESHELL translates the
prompt into English, and if your response is that you want to unpack the file
before compressing it, it immediately runs UPACKEXE.  Then it runs LZEXE to
complete the compression.  In other words, you don't go back to DOS until
both programs have been run.  The effect is to make these two fine utilities
act as a single program.

  Both UPACKEXE and LZEXE save source files as backups, changing their names
to *.OLD.  This can create a problem when you run UPACKEXE then run LZEXE.
The *.OLD backup file saved by UPACKEXE will be replaced by the *.OLD file
saved by LZEXE -- you end up losing the EXEPACKed *.OLD file.  LZESHELL
eliminates this problem by immediately renaming the *.OLD file produced by
UPACKEXE to *.OPK.  This leaves you with two backup files -- one for the
original EXEPACKed file (*.OPK) and one for the unpacked file (*.OLD).  The
third file will be your compressed EXE file.  If the compressed file works,
you can remove both backup files from your disk.  Otherwise, you can erase
the compressed EXE file and rename one of the backups to *.EXE (probably the
EXEPACKed one, *.OPK, since it's the original and it's smaller).

  LZESHELL also generates English prompts for another situation that LZEXE
v.0.91 detects, namely the use of overlays by the EXE file.  Here you are
given the choice of aborting the compression or continuing it (taking the
chance that the compressed file won't work).  LZEXE v0.91 also detects
"internal overlays" (I'm not sure what those are), but in that situation it
only issues a warning and requires no user choices.  LZESHELL translates the
warning into English.

  Finally, LZESHELL readjusts the timestamp on the compressed file so it's the
same as it was in the original file.  When LZEXE is run by itself it always
gives the compressed file the current date, which some people feel is a short-
coming since it obliterates a useful identifier.


RUNNING THE PROGRAM

LZESHELL (v1.0), LZEXE (v.0.91), and UPACKEXE (v1.00), or their directories,
should be on your system's path (use the DOS PATH command to do this,
preferably in an AUTOEXEC.BAT file).  This will allow you move freely from
directory to directory to compress EXE files.  You should always go to the
directory of the file you want to compress.

  To run the program type the following at the DOS prompt:

              LZESHELL [EXE file to be compressed]

  Translated warnings and prompts will appear in a box on your screen.  At the
end of the compression a "scorecard" will appear showing you the file size
before and after compression, the size reduction in bytes, and the percent
reduction.


DISTRIBUTION

LZESHELL may be freely distributed provided it's not modified and no money
is charged for it.


DISCLAIMER

Pete Petrakis accepts no responsibility or liability for any mishap
resulting from the use of LZESHELL.  To protect yourself against loss of
valuable files you are advised to keep backups in a safe place or to check
the performance of compressed files thoroughly before discarding their backups.