Re: [PATCH v1 02/19] man/man2/access.2: HISTORY: Specify different access(2) prototypes

[Alejandro Colomar <alx@kernel.org>]

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Hi Seth,

On Mon, Jan 19, 2026 at 11:55:06AM +0000, Seth McDonald wrote:
> access(2) was specified in POSIX.1-1988 with the prototype
> int access(char *path, int amode); [1]
> 
> POSIX.1-1990 then changed the prototype to
> int access(const char *path, int amode); [2]

I suspect this is common to all APIs specified in those standards,
right?  Or is it specific to this API?

'const' was invented by ANSI C89, so I expect the change was around that
time.

On the change itself, it wasn't a breaking change: programs written
before the addition of const wouldn't notice that const has been added
to the prototype.

The change would be noticed by a program written today, but compiled in
such an old system.  However, I expect such a program to be aware that
pre-ANSI C was different, and it would have to adapt to it anyway.
const would be something that would have to be globally ignored, with
something like

	#define const

Given this should be of no importance to users, I'd prefer not
documenting this difference.

What do you think?


Cheers,
Alex

> [1] IEEE Std 1003.1-1988, Section 5.6.3 "File Accessibility".
> [2] IEEE Std 1003.1-1990, Section 5.6.3 "Check File Accessibility".
> 
> Signed-off-by: Seth McDonald <sethmcmail@pm.me>
> ---
>  man/man2/access.2 | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/man/man2/access.2 b/man/man2/access.2
> index 1ef65a982f04..c0bcf016ae5c 100644
> --- a/man/man2/access.2
> +++ b/man/man2/access.2
> @@ -342,6 +342,13 @@ .SH HISTORY
>  .TP
>  .BR faccessat2 ()
>  Linux 5.8.
> +.P
> +POSIX.1-1988 initially specified the function signature of
> +.BR access ()
> +with a non-const-qualified
> +.I path
> +parameter.
> +This was remedied in POSIX.1-1990.
>  .SH NOTES
>  .BR Warning :
>  Using these calls to check if a user is authorized to, for example,
> -- 
> 2.47.3
> 



-- 
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