On Sat, Jun 10, 2023 at 10:15:53AM +0200, Theo Buehler wrote:
> On Sat, Jun 10, 2023 at 09:00:54AM +0200, Claudio Jeker wrote:
> > Instead of building an API for ibufs to handle dynamic strings use
> > open_memstream(3) which does the same via stdio.
> >
> > Now open_memstream() requires a bit more plumbing (one needs to close the
> > FILE stream and free the buffer) but on the plus side you can use all
> > stdio functions like fprintf() to fill this string.
> > While doing this also add error handling and check if the generated string
> > was created successfully before calling log_info().
>
> This is a lot better than the mess that was there before. One thing I'm
> not entirely sure about is whether fflush() can fail. I think it can't
> since previous writes should already have led to reallocations, so
> another ferror() after fflush() would probably be overdoing it.
Indeed, I was under the impression that fflush() would just update the
pointers but actually the fflush() call is needed to flush out the
internal stdio buffer into the open_memstream() buffer. So the fflush()
should happen before checking for errors. Another option is to use
setvbuf() with _IONBF to make the FILE stream unbuffered.
So the new pattern is:
fflush(spif);
if (ftello(spif) > 0 && !ferror(spif)) {
log_info(...
--
:wq Claudio
