Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!utgpu!water!watmath!clyde!ima!haddock!karl From: karl@haddock.UUCP Newsgroups: comp.lang.c Subject: return values and errno Message-ID: <1853@haddock.ISC.COM> Date: Thu, 3-Dec-87 15:42:25 EST Article-I.D.: haddock.1853 Posted: Thu Dec 3 15:42:25 1987 Date-Received: Sun, 6-Dec-87 16:52:36 EST References: <10224@brl-adm.ARPA> <9272@mimsy.UUCP> <1804@geac.UUCP> <1761@haddock.ISC.COM> <244@papaya.bbn.com> Reply-To: karl@haddock.ima.isc.com (Karl Heuer) Organization: Interactive Systems, Boston Lines: 10 I wrote: > errno = 0; > unlink(fname); > if (errno != 0) abort(); and was informed that this is unportable usage because the POSIX spec doesn't guarantee that functions will preserve errno on success. Tell me then, o POSIX gurus, whether there are still functions that can return -1 on success (e.g. ptrace() and possibly nice())? If so, does POSIX specify what these functions are allowed to do with errno in such a case?