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Date: Mon, 8 Dec 1997 02:42:42 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199712071542.CAA04419@godzilla.zeta.org.au>
To: brian@awfulhak.org, evanc@synapse.net
Subject: Re: _POSIX_SAVED_IDS
Cc: freebsd-current@FreeBSD.ORG
Sender: owner-freebsd-current@FreeBSD.ORG
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>Here's a problem for you: on systems where I have a saved-set seteuid(), I
>would prefer to use it instead of a setreuid() swap.  How do I tell if I
>have a saved-set seteuid() if _POSIX_SAVED_IDS is not defined (besides
>running a setuid test program -- I'd prefer something that autoconf could
>figure out on its own)?

Same as if _POSIX_SAVED_IDS is defined - it has nothing to do with seteuid(),
since setreuid() is not in POSIX.

If you can't run a setuid program, then you'll have to read all the man
pages, and maybe the system sources, and maybe the kernel binary - a
difficult task for autoconf :-).  I think you should depend on running
a setuid test program.  If the program can be trusted at runtime, it
can probably be trusted at build time.

Bruce