Path: utzoo!attcan!uunet!cs.utexas.edu!samsung!think!snorkelwacker!spdcc!ima!haddock!karl
From: karl@haddock.ima.isc.com (Karl Heuer)
Newsgroups: comp.lang.c
Subject: Re: Is "if (!pointer)" as portable as "if (pointer == NULL)" ???
Keywords: portability, pointers, NULL
Message-ID: <16438@haddock.ima.isc.com>
Date: 11 Apr 90 16:42:24 GMT
References: <656@hades.OZ> <1461@tkou02.enet.dec.com> <717@ssp11.idca.tds.philips.nl>
Reply-To: karl@haddock.ima.isc.com (Karl Heuer)
Organization: Interactive Systems, Cambridge, MA 02138-5302
Lines: 10

In article <717@ssp11.idca.tds.philips.nl> dolf@idca.tds.PHILIPS.nl (Dolf Grunbauer) writes:
>How about [skipping the test for NULL and writing just]
>	free(buffer)
>The manual pages I know allow a NULL pointer and doing nothing in this case.
>Is this generally true ?

It's a new feature of the ANSI C library.  It should be avoided if you need
to retain portability to old implementations.

Karl W. Z. Heuer (karl@ima.ima.isc.com or harvard!ima!karl), The Walking Lint