Roland Mainz wrote: >Ian Collins wrote: > > >>Roland Mainz wrote: >> >It can't fail directly but you can hit the end of the stack. However for >|libc::wordexp()| there is enougth room (for the SMF process (the only >comsumer of |libc::wordexp()| in OS/Net (and I strongly doubt that other >consumers are low on stack memory)) multiple megabytes are still >available). For other applications it is usefull to have a macro which >uses C99 variable length arrays up to a fixed limit and then switches >over to use |malloc()| beyond that size (and sets the size of the vla >buffer to zero). > > I assume you have a matching macro to call free in the case where malloc is used?
> > >>>>Speaking of which, where does "140" come from in the dynamic array >>>>definition? It would be better not to have a magic number like that. >>>> >>>> >>>It's no magic number, it is the maximum size the consumers of the buffer >>>will use in any case. >>> >>> >>But it (140) is still a magic number, maybe make it a const size_t? >> >> > >Uhm... AFAIK this is just a question of style, right ? |size_t >sizeofbuffer=140+string_length ; char buffer[sizeofbuffer]| or |char >buffer[140+string_length]| are pretty much equivalent... but it may be a >good idea to add a comment how the value "140" was calculated. > > > It's more than style, good practice and most C coding standards state that magic number in code are bad. Consider something like char buffer[max_consumer_size+string_length]; Give the constant for 140 a descriptive and and save yourself a comment. Ian
