Am So, 13.02.2011, 13:20 schrieb Julian H. Stacey: > Hi Hackers > Ref.: man 3 getopt > int getopt(int argc, char * const argv[], const char *optstring); > Ref.: K&R 2nd Ed P.211 last indent, 2nd sentence > The purpose of const is to announce [objects] that may be > placed in read-only memory, and perhaps to increas[e] opportunities for optimization > optstring is obviously const, > but I don't see that argv can calim to be const ?
Hi Julian, the prototype is in line with the Single Unix Specification v4 aka IEEE Std. 1003.1-2008 (sorry no URL, I have checked my local copy, check <http://www.opengroup.org/> you can access it free of charge after registering name and email address). The const basically states that the argv[] elements (i. e. the char * pointers) are const[ant], or, read another way, that getopt promises not to mess with the *pointers* but is free to modify the actual strings pointed to (with the usual constraints of not assuming they can be extended, for instance) - and I don't see the problem in that. Does that help? If not, please explain you confusion in a bit more detail. Best Matthias -- Matthias Andree _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[email protected]"
