LX lite - a compressor for OS/2 executables

Name LX lite - a compressor for OS/2 executables
Version 1.3.2
Author Andrew Zabolotny
(see EMail Addresses)
Distrib. Freeware
Type EXE program
Price -
Source Internet
Name: LXLT132.*

This is a fantastic program to pack OS/2 executables in Linear Executable (LX) format. OS/2 uses the LX format for .EXE, .DLL, .PDR, .QPR, .DRV, .FON and .SYS files. Virtual Device Drivers (VDDs) for DOS sessions are also in LX format. You can even compress the OS/2 kernel (os2krnl)!
LX compresses the files in the same way as LINK386 does. The decompression algorithm is part of the OS/2 WARP program loader. So files compressed with LX are "simple" OS/2 executables. There's no additional stub program necessary to uncompress the compressed files.

The only drawback of this tool:

You cannot execute compressed executables under OS/2 prior to WARP because the decompression code was first introduced in WARP. But that's no great problem because LxLite can also decompress compressed files again.

Conclusion:

LxLite is one of the most useful tools for OS/2 I've seen so far.

(see Using REXX if booted from diskette for one use of LxLite)

Another useful tool contained in this package is UNLOCK.EXE:

"unLock is a simple utility which allows to 'unlock' application executables which are currently in use. Normally when an executable is loaded by OS/2 its file is open with a deny-write sharing mode. This is done because LX format structure is designed not to swap out unused pages in executables each time when they aren't needed anymore, but rather to discard them. When a discarded page is needed OS/2 simply reads it again from the executable.
However, there is still a way to replace executables 'on-the-fly' even if they are currently running. There is an so-called 'well-known-undocumented' function (which in fact means that it won't be neccesarily supported in future versions of OS/2) which allow to disable sharing protection on such files. Before doing that OS/2 reads entire executable in swap file, then page swapping is done as with usual memory. If you'll 'unlock' many running executables at the same time you can notice an increase in swap file size.
So, this is just an temporary workaround, you have better to reboot after doing all neccesary things on former locked files. The command-line format of unLock is much like lxLite's, except that it have much less options :-)"


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