Re: strerror(0) POSIX compliance

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Thu, Mar 24, 2016 at 05:09:50PM +0000, Christos Zoulas wrote:
> Actually not; syscalls set errno on error, don't clear errno on success [1].
> Thus it is incorrect code to test errno if the syscall succeeded. It shows
> nothing, try:

Actually, it is even worse. errno is essentially *undefined* after
successful calls. It only ever has a well defined value after a failing
operation. This is most noticable with things like stdio, were
intermediate failures can be handled without resetting errno.

Joerg