Date: Sun, 18 Oct 2009 22:15:58 -0700 From: Gary Kline <kline@thought.org> Cc: freebsd-questions@freebsd.org Subject: Re: need C help, passing char buffer[] by-value.... Message-ID: <20091019051557.GC9657@thought.org> In-Reply-To: <20091019054344.bb4822ca.freebsd@edvax.de> References: <20091019013337.GA9522@thought.org> <72213BBF-5E05-430D-BF9A-FCD2666951C6@hiwaay.net> <20091019054344.bb4822ca.freebsd@edvax.de>
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On Mon, Oct 19, 2009 at 05:43:44AM +0200, Polytropon wrote: > On Sun, 18 Oct 2009 22:23:43 -0500, David Kelly <dkelly@hiwaay.net> wrote: > > When not using a count to indicate how much data is in a char* you > > should always test for null. Testing for null is not a sure fire way > > to prevent buffer over runs but its better than nothing. > > There are means like > > #include <assert.h> > ... > assert(s); > > to make sure s is not NULL, or testing for it explicitely like > > if(!s) > ... error handling here ... > > is possible. Furthermore, it is a proven way to give a length > argument along with the (char *) argument, such as the "new" > l-functions for strings, e. g. strlcat() and strlcpy(), do. > > char *skiptags(char *s, int l); > > You can even double-check for l begin != 0. Or you employ a > test with strlen() function-internally. > > right; i will add error checking once i've got things working. but i think i meant to say that i was calling by-reference, sing fgets was reading the file from a char buffer[256]; or whatever. so, given this, shouldn't i need to step past some N bytes of "buffer[]? i'll experiement and see, again, but in my one compile that worked, by-value, left in the <TAGS> </TAGS> gary > > -- > Polytropon > Magdeburg, Germany > Happy FreeBSD user since 4.0 > Andra moi ennepe, Mousa, ... > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org" -- Gary Kline kline@thought.org http://www.thought.org Public Service Unix http://jottings.thought.org http://transfinite.thought.org The 7.31a release of Jottings: http://jottings.thought.org/index.php
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