>>For distribution purposes, the Win32 API has support for file decompression in the API; a whole set of calls for extracting files which are LZ compressed are available.
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>Ed,
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>As I recall, these compression functions have been available at least since Win16. I did some playing around with them because of their availability. Again, as I recall, I wasn't terribly impressed with them. I can't remember whether the reason was that they were either terribly slow and/or the compression ratio wasn't as good as PKZip.
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It uses the file format supported by the command line 'EXPAND' executable; there's no corresponding compression available in the API. A number of install products, including InstallShield and VSI have support for these functions; the biggest argument in favor of their use is that the decompression can be used with deferred file copy actions, where you can't make an immediate update of an OS component because the OS is using it, so the file is flagged for deferred copy when the system next reboots.

It's not a general replacement for Zip compression; I use WinZip (registered) for programmatic compression/decompression, since I already have WinZip and the code to use it, and it's no more expensize than DynaZip, and use the commercial version of the WinZip Self-Extractor for building app updates to send out to clients; since I install WSH as a part of my initial install, I can count on being able to have the self-extractor open itself and fire a VBScript to do the update work.

>I hadn't thought to revisit these under Win32, perhaps doing so might be in order.