Re: [PATCH] scanf.3: Do not mention the ERANGE error

[Alejandro Colomar <alx.manpages@gmail.com>]

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Hi Ian,

On 12/8/22 13:34, Ian Abbott wrote:
> The `scanf()` function does not intentionally set `errno` to `ERANGE`.
> That is just a side effect of the code that it uses to perform
> conversions.  It also does not work as reliably as indicated in the
> 'man' page when the target integer type is narrower than `long`.
> Typically (at least in glibc) for target integer types narrower than
> `long`, the number has to exceed the range of `long` (for signed
> conversions) or `unsigned long` (for unsigned conversions) for `errno`
> to be set to `ERANGE`.
> 
> Documenting `ERANGE` in the ERRORS section kind of implies that
> `scanf()` should return `EOF` when an integer overflow is encountered,
> which it doesn't (and doing so would violate the C standard).
> 
> Just remove any mention of the `ERANGE` error to avoid confusion.
> 
> Fixes: 646af540e467 ("Add an ERRORS section documenting at least some of the errors that may occur for scanf().")
> Cc: Michael Kerrisk <mtk.manpages@gmail.com>
> Signed-off-by: Ian Abbott <abbotti@mev.co.uk>

I see.  How about saying something like "it may also fail for any of any errors 
that functions used to perform the conversions may fail"?

Cheers,

Alex

> ---
>   man3/scanf.3 | 7 -------
>   1 file changed, 7 deletions(-)
> 
> diff --git a/man3/scanf.3 b/man3/scanf.3
> index ba470a5c1..c5ff59f45 100644
> --- a/man3/scanf.3
> +++ b/man3/scanf.3
> @@ -576,10 +576,6 @@ is NULL.
>   .TP
>   .B ENOMEM
>   Out of memory.
> -.TP
> -.B ERANGE
> -The result of an integer conversion would exceed the size
> -that can be stored in the corresponding integer type.
>   .SH ATTRIBUTES
>   For an explanation of the terms used in this section, see
>   .BR attributes (7).
> @@ -609,9 +605,6 @@ The functions
>   and
>   .BR sscanf ()
>   conform to C89 and C99 and POSIX.1-2001.
> -These standards do not specify the
> -.B ERANGE
> -error.
>   .PP
>   The
>   .B q

-- 
<http://www.alejandro-colomar.es/>

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