Re: fdprintf() Anyone?

For a quick check on most newlib functions, search Cygwin compatibility pages:

	https://cygwin.org/cygwin-api/compatibility.html

bearing in mind that Cygwin may have its own variants supporting hosted features 
like multiple character sets, IPC, languages, locales, time zones, and similar.

On 2025-12-11 17:38, Joel Sherrill wrote:
> Thank you for the quick response and pointing out the POSIX standard functions!!!
> 
> I am honestly quite happy not to have to seriously add anything non-standard.
> 
> Looking at the git log, these have been in newlib a LONG time.
> 
> Thanks again.
> 
> --joel
> 
> On Thu, Dec 11, 2025 at 6:19 PM John Scott wrote:
> 
>     Joel Sherrill wrote:
>      > int fdprintf (int fd, const char *format,...)
> 
>     POSIX.1-2008 has already standardized a version of printf() for writing to
>     file descriptors, and it has the same prototype: it's called dprintf
>     (without the 'f' at the beginning). There is also a va_list variant named
>     vdprintf(). These are widely available and I think GNU folks drove their
>     specification.
> 
>     These are already included at https://sourceware.org/git/?p=newlib-
>     cygwin.git;a=blob;f=newlib/libc/stdio/dprintf.c <https://sourceware.org/
>     git/?p=newlib-cygwin.git;a=blob;f=newlib/libc/stdio/dprintf.c> however I
>     think the following text is no longer accurate:
>      > PORTABILITY
>      > This function is originally a GNU extension in glibc and is not portable.
> 
>     Post-standardization I think implementations picked this up without
>     hesitation. You probably just missed this; in fact, dprintf() returns the
>     same value as fdprintf() does to indicate success or error. I think the
>     NetBurner folks giving their function a different name was, at least in
>     hindsight, a botch.
> 
>      > But the user is using a system where they are in <fcntl.h>.
>     For compatibility with that particular application I'm sure you could make
>     fdprintf() an alias for dprintf(). If a user is wanting to use Newlib with
>     NetBurner such a shim might be welcome in a directory specific to that class
>     of systems.
> 
>      > Is there any interest in these eventually landing in newlib?
>     The equivalent standard functions are already in Newlib and my preference
>     (as someone who, to be frank, has never contributed to Newlib) is to do
>     nothing here. If your users are porting an application away, defining '-
>     Dfdprintf=dprintf' may be all they need to do.

-- 
Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retrancher  but when there is no more to cut
                                 -- Antoine de Saint-Exupéry