On Mon, Oct 19, 2009 at 05:43:44AM +0200, Polytropon wrote: > On Sun, 18 Oct 2009 22:23:43 -0500, David Kelly <[email protected]> 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 ...
You are missing my point that *s == 0 is not a good out of bounds range check. > 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. strlen() knows nothing about the buffer allocation. As I originally said, testing for null (and my example tested) is not foolproof but its better than nothing. One should *also* test for the known end of the allocated buffer. -- David Kelly N4HHE, [email protected] ======================================================================== Whom computers would destroy, they must first drive mad. _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[email protected]"
