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From: earl@mips.UUCP (Earl Killian)
Newsgroups: comp.arch,comp.unix.wizards,comp.os.misc
Subject: Re: Shared libraries
Message-ID: <710@gumby.UUCP>
Date: Fri, 25-Sep-87 18:20:34 EDT
Article-I.D.: gumby.710
Posted: Fri Sep 25 18:20:34 1987
Date-Received: Sun, 27-Sep-87 10:51:35 EDT
References: <2067@sfsup.UUCP> <2903@phri.UUCP> <6461@brl-smoke.ARPA> <2906@phri.UUCP>
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In article <2906@phri.UUCP>, roy@phri.UUCP (Roy Smith) writes:
[lots of words about programming in the real world]

I agree with what Roy Smith wrote with respect to the real world.
But, shared libraries aren't bad for his world.  I think they make
life simpler.  At least if done right (I don't think System V shared
libraries qualify, but I don't know).  On Multics, it works the way
Henry Spencer expects; to fix a broken function, you simply put a
replacement in the search path, and the problem is fixed.  You don't
need to relink everything that's been worked in since the bug first
appeared (finding all the programs linked with the bad system() in
your example might be a real chore, depending on when the bug is
discovered).

Bug fixes, workarounds, and new features are major uses of Multics
dynamic linking.  Consider something trivial on Multics and impossible
on vanilla Unix.  I login to a system over the arpanet from far away.
It prints out time in the wrong time zone.  Suppose there's no option
to specify a timezone.  I just put a new binary to ascii time
conversion function in my search path, and I'm happy.  On Unix I'd
have to relink all the appropriate programs in /usr (not easy if I
don't have the source).