Re: [PATCH v2 1/2] system_data_types.7: Add 'error_t'

["Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>]

Hi Alex,

On 10/26/20 11:16 PM, Alejandro Colomar wrote:
> Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
> ---
>  man7/system_data_types.7 | 39 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
> 
> diff --git a/man7/system_data_types.7 b/man7/system_data_types.7
> index 49ca2d8e1..4930aac8b 100644
> --- a/man7/system_data_types.7
> +++ b/man7/system_data_types.7
> @@ -199,6 +199,45 @@ See also the
>  .I float_t
>  type in this page.
>  .RE
> +.\"------------------------------------- error_t ----------------------/
> +.TP
> +.I error_t
> +.RS
> +Include:
> +.IR <argz.h> ,
> +or
> +.IR <envz.h> .
> +Alternatively,
> +.IR <errno.h> .
> +.PP
> +An integer type
> +used for error reporting.
> +A value of 0 means success, and nonzero means failure.
> +Portable programs should use
> +.I int
> +instead.
> +.PP
> +Conforming to:
> +Present in glibc.
> +It is not standardized by the C language standard nor POSIX.
> +.PP
> +Notes:
> +C11 standardized a similar type as an optional extension:
> +.IR errno_t .
> +However,
> +.I errno_t
> +is not present in POSIX.
> +.PP
> +.I <errno.h>
> +defines this type if the macro
> +.B _GNU_SOURCE
> +is defined before including the header.
> +.PP
> +See also:
> +.BR argz_add (3),
> +.BR envz_add (3),
> +.BR feature_test_macros (7)
> +.RE
>  .\"------------------------------------- fd_set -----------------------/
>  .TP
>  .I fd_set


So, I must say that I am skeptical about adding this type to the page.
There is a trade-off between having useful info and creating a page
that becomes so large that it becomes unwieldy.

error_t is an obscure [1], nonstandard type used by two API sets
(one of which is roughly a special case of the other). I'm so far
unconvinced of the value of adding this typr to the page.

Cheers,

Michael

[1] Before Jonny Grant's mail yesterday, which I presume was 
the inspiration for this patch, I had either neither heard of
the type or at least long ago forgotten about it.

-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/