This is the mail archive of the libc-alpha@sourceware.org mailing list for the glibc project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH 2/3] manual: clarify errno value on success [BZ #22615]


On 12/21/2017 02:54 PM, Aurelien Jarno wrote:
> The current glibc manual is ambiguous about the errno value on success
> and suggests that it is left unchanged. Some functions might and
> sometimes do change the errno value, however they never set it to 0.
> 
> This patch clarifies this section of the manual.
> 
> Changelog:
> 	[BZ #22615]
> 	* manual/errno.texi (Checking for Errors): Explicitly say that errno
> 	might be set on success.

OK.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

> ---
>  ChangeLog         |  6 ++++++
>  manual/errno.texi | 12 ++++++------
>  2 files changed, 12 insertions(+), 6 deletions(-)
> 
> diff --git a/ChangeLog b/ChangeLog
> index cb41a07a25..7bf30d27ef 100644
> --- a/ChangeLog
> +++ b/ChangeLog
> @@ -1,3 +1,9 @@
> +2017-12-21  Aurelien Jarno  <aurelien@aurel32.net>
> +
> +	[BZ #22615]
> +	* manual/errno.texi (Checking for Errors): Explicitly say that errno
> +	might be set on success.
> +
>  2017-12-21  Aurelien Jarno  <aurelien@aurel32.net>
>  
>  	[BZ #22611]
> diff --git a/manual/errno.texi b/manual/errno.texi
> index 3e0b862c4e..eaac8e6dca 100644
> --- a/manual/errno.texi
> +++ b/manual/errno.texi
> @@ -50,12 +50,12 @@ possibility except when writing signal handlers.
>  The initial value of @code{errno} at program startup is zero.  Many
>  library functions are guaranteed to set it to certain nonzero values
>  when they encounter certain kinds of errors.  These error conditions are
> -listed for each function.  These functions do not change @code{errno}
> -when they succeed; thus, the value of @code{errno} after a successful
> -call is not necessarily zero, and you should not use @code{errno} to
> -determine @emph{whether} a call failed.  The proper way to do that is
> -documented for each function.  @emph{If} the call failed, you can
> -examine @code{errno}.
> +listed for each function.  These functions never set @code{errno} to zero
> +and might set it to a non-zero value when they succeed; thus, the value of
> +@code{errno} after a successful call is not necessarily zero, and you
> +should not use @code{errno} to determine @emph{whether} a call failed.
> +The proper way to do that is documented for each function.  @emph{If} the
> +call failed, you can examine @code{errno}.

OK.

>  
>  Many library functions can set @code{errno} to a nonzero value as a
>  result of calling other library functions which might fail.  You should
> 


-- 
Cheers,
Carlos.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]