Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!samsung!uunet!mtxinu!ed
From: ed@mtxinu.COM (Ed Gould)
Newsgroups: comp.os.mach
Subject: Re: seekdir & telldir in 2.5 libc source
Message-ID: <1991May7.040225.429@mtxinu.COM>
Date: 7 May 91 04:02:25 GMT
References: <3047@fai.UUCP>
Reply-To: ed@mtxinu.COM (Ed Gould)
Organization: mt Xinu, Berkeley
Lines: 27

>We are working on porting Mach 2.5 to new Fujitsu hardware.  In the libc
>source that is distributed with Mach 2.5, if "CMU" is defined, there is
>code purposely inserted to make "seekdir" and "telldir" not work and
>huge warnings of the form "Don't use telldir under MACH !!!".

That code is there because there are filesystems for which seekdir
and telldir cannot be made to work, notably AFS.  Even under the
standard UFS, they are not absolutely guaranteed.  The CMU environment
includes AFS, hence the use of that code.

The Mach distribution from mt Xinu contains a complete adaptation
of the BSD code to this environment, including, e.g., a tar that
doesn't need seekdir.

Arguably, that code shouldn't be conditional on CMU being defined,
but it would have taken lots longer than 18 months to clean out
all of those inconsistencies.  We decided to leave "CMU" defined
by default, but to remove the really CMU-specific (or at least the
Computer Science specific) to be contitional on CMUCS.  We were
supposed to get that all done in 12 months, but there was just too
much.

-- 
Ed Gould			No longer formally affiliated with,
ed@mtxinu.COM			and certainly not speaking for, mt Xinu.

"I'll fight them as a woman, not a lady.  I'll fight them as an engineer."