* Return value is still valid, caller should just check whether end[0]
* is a valid terminating char for particular case. OTOH, if caller
* requires '\0' terminated input, [s]he can just check errno == 0.
* Return value is still valid, caller should just check whether end[0]
* is a valid terminating char for particular case. OTOH, if caller
* requires '\0' terminated input, [s]he can just check errno == 0.