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From: roy@phri.nyu.edu (Roy Smith)
Newsgroups: comp.unix.internals
Subject: Re: executing a stream / a compressed file
Message-ID: <1991Feb15.150413.14443@phri.nyu.edu>
Date: 15 Feb 91 15:04:13 GMT
References: <1991Jan15.204849@IASTATE.EDU> <118868@uunet.UU.NET> <9950@dog.ee.lbl.gov>
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Organization: Public Health Research Institute, New York City
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torek@elf.ee.lbl.gov (Chris Torek) writes:
> the kernel could run compressed binaries by uncompressing them into a
> swap image, and running the swap image (this would be easier in pure
> swapping systems) or by uncompressing them into ordinary unlinked files
> and running those.  The implementation of the latter is trivial even in
> user code.

	Gaak!  Compression does not belong in the kernel (he says with
great authority and religious overtones), unless maybe you're talking about
a driver for a DES chip.

	All you really need to implement compressed executables (as Chris
hinted) is to start the executable files with "#!/bin/uncompressexec" which
would uncompress the rest of the file, put it back in place of itself (if
you want to cache uncompressed executables, which is probably a good idea)
and then overlay itself with the new executable.  A nightly cron job could
recompress stuff that hasn't been run in a while.
--
Roy Smith, Public Health Research Institute
455 First Avenue, New York, NY 10016
roy@alanine.phri.nyu.edu -OR- {att,cmcl2,rutgers,hombre}!phri!roy
"Arcane?  Did you say arcane?  It wouldn't be Unix if it wasn't arcane!"