On Fri, Aug 14, 2026 at 12:36:36PM +0200, Ingo Schwarze wrote:
> Hi Avon,
>
> Avon Robertson wrote on Fri, Aug 14, 2026 at 08:52:33PM +1200:
>
> > I will see if what I need can be found in xrandr.c.
>
> In addition to that, also look at
>
> $ man 3 Xrandr
>
> which is the API that xrandr(1) uses to dig up the information
> it prints. Unfortunately, that manual page appears to be
> incomplete. For example, the function XRRGetOutputInfo(3)
> appears to be relevant to your purpose. That function is
> declared in <X11/extensions/Xrandr.h>, but not documented,
> which is kind of typical in X11 - much of the documentation
> is missing, and what is available is often outdated and/or vague.
>
> Either way, X11 programming is not exactly for the faint-hearted.
> You will likely not get around without digging through some
> source code, as it appears Thomas already correctly suggested
> (though i do not see any posting on his part saying that publicly,
> sorry if i missed it).
>
> In general, when people want to write C programs, OpenBSD
> developers encourage reading the docs in /usr/share/man/
> and the source code in /usr/src/. With /usr/X11R6/man/
> and /usr/xenocara/, the same exercise furthers your education
> significantly less while inducing significantly more pain,
> but that doesn't mean it is impossible.
>
> Have fun in Xrandr.h (however doubtful that may seem 8-),
> Ingo
Thank you for the information Ingo. My day has just begun and when
I have dealt to my mail I will look at xrandr{x,h}.
In my reply to Thomas, I did not include Thomas' post (as it
appeared to be MIME encoded).
--
aer
