AW: gamma(3)

[Walter Harms <wharms@bfs.de>]

So we have agreed that existing functions should be documented.
and so far i understand we are taking about the  _r only.

the whole patch is the function definition. What could be done more is to mark the function as obsolete/compatibility only.

The explanation for signgam should  be copied to lgamma().

________________________________________
Von: Alejandro Colomar (man-pages) <alx.manpages@gmail.com>
Gesendet: Freitag, 21. Mai 2021 16:47:29
An: Walter Harms
Cc: linux-man@vger.kernel.org; Michael Kerrisk (man-pages)
Betreff: Re: gamma(3)

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On 5/21/21 4:08 PM, Walter Harms wrote:
> (before we misunderstand each other i do not insists on that patch)

No problem about it.  You could insist on if you wanted to :p

I'm not sure yet about what we should do.

>
> The function is available and that should be documented.

I tend to agree with that.

> They seem available for some time, but glibc says: These functions
> exist for compatibility reasons.

Exactly.  But that means it exists for old code to still work.  New code
should not use these.  So the manual page should serve 2 purposes:

*) discourage its use
*) help migrating from gamma(3) to lgamma(3)

The first one is already clear.  For the second one, I think that the
SYNOPSIS and ATTRIBUTES is enough.

>
> What is about a merger with lgamma() ?

I like it separated (as is).  It serves the purpose of redirecting to
either lgamma or tgamma depending on what the reader wants.

>
> adding to the notes section something like that:
>     glibc version
>         Glibc  has  a  gamma() function (and _r) that is equivalent to
>         lgamma(3) and computes the natural logarithm of the Gamma function.
>         That function is deprecated and should not be used in newer programs.
>
>
> re,
>   wh

I think that to document those, but keep it to a minimum, I'd add the
functions to the sections NAME and SYNOPSIS, and nothing more.  The rest
is very generic and mainly says "don't use this".  The only thing that
would maybe need an update is the ATTRIBUTES section, but I wouldn't
mind if we left it as is.


What do you think?

Cheers,

Alex


--
Alejandro Colomar
Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/
http://www.alejandro-colomar.es/