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From: smb@ulysses.att.com (Steven Bellovin)
Newsgroups: comp.unix.wizards
Subject: Re: more BSD strangeness -- syslogd.c
Message-ID: <13093@ulysses.att.com>
Date: 11 Jun 90 15:10:40 GMT
References: <1990Jun8.070904.7466@athena.mit.edu> <36447@sequent.UUCP> <3446@auspex.auspex.com>
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In article <3446@auspex.auspex.com>, hitz@auspex.auspex.com (Dave Hitz) writes:
} This answers the question "why close all open files", but it doesn't
} answer the question, "why open anything at all for descriptors 0, 1 and
} 2."  If it makes no reference to stdin, stdout, stderr, why must there
} be something open for them?
} 
} I can (and have) made up several answers for this.  Anyone know the real
} one?  What happens if you just leave the descriptors closed?

It probably doesn't apply to syslogd, but in general if 0,1,2 are
closed you confuse a lot of programs that you fork/open/dup/exec to.

Yes, I've seen it happen.  Many times.