Re: [libgpiod][PATCH 2/3] libgpiosim: new library for controlling the gpio-sim module

[Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>]

On Thu, Apr 29, 2021 at 03:07:49PM +0200, Bartosz Golaszewski wrote:
> On Thu, Apr 29, 2021 at 1:23 PM Andy Shevchenko
> <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> > On Thu, Apr 29, 2021 at 11:47:33AM +0200, Bartosz Golaszewski wrote:

...

> > > +/* We don't have mkdtempat()... :( */
> >
> > But we have tmpnam() / tmpnam_r(), why to reinvent it below?
> >
> 
> Because of this:
> 
> $man tmpnam_r
> ...
> The created pathname has a directory prefix P_tmpdir.
> ...
> 
> And this:
> 
> ./stdio.h:120:# define P_tmpdir "/tmp"

Still you may advance the pointer by the length of P_tmpdir + 1.

...

> > > +     for (i = 0; i < num_names; i++)
> > > +             written += snprintf(buf + written, size - written,
> > > +                                 "\"%s\", ", names[i] ?: "");
> > > +     buf[size - 2] = '\0';
> >
> > Dunno if you can use asprintf() and actually replace NULL by "" in the original
> > array. Ah, see you already using it somewhere else, why not here?
> >
> 
> Not sure what you mean, we can't use asprintf() to create a composite
> string like what is needed here. Can you give me an example?

I have got this after sending. Either you need to create a format string with
va_args, or do it manually.


-- 
With Best Regards,
Andy Shevchenko