Re: sys_errlist deprecated? (ITS#3111)

[Kurt@OpenLDAP.org]

I think I'd like to commit a macro (and autodetection)
which follows the following prototype:
        const char * STRERROR_R(n,b,s)

Will use strerror_r (either version) if available in normal
libc (e.g, will ignore strerror_r only in threading libraries)
and its flavor detectable.  Otherwise, will use sys_errlist
if available.  Otherwise, strerror.

Kurt

At 08:19 AM 4/24/2004, ando@sys-net.it wrote:
>Kurt D. Zeilenga wrote:
>
>>Note that strerror_r() is not terrible portable.
>>The POSIX defn is:
>>  int strerror_r(int errnum, char *strerrbuf, size_t buflen);
>>
>This is the cleanest: only look at the buffer
>
>>
>>while some systems (like Linux) use:
>> char *strerror_r(int errnum, char *buf, size_t buflen);
>>
>This should be the most efficient, because it writes the buffer
>only if required
>
>>
>>and other systems one just uses strerrror() (which on these
>>systems uses a thread specific buffer unknown error numbers).
>>
>This is mostly what Howard suggested: strerror is likely to return
>a constant string, or "unknown error %d" in a static buffer; so if
>we don't mind about %d (because we already log it before the message)
>all we need to do is:
>    char *s0 = strerror(-1), *s = strerror(e);
>    if (s == s0)
>        return "Unknown error";
>    return s;
>
>However, we cannot count over this behavior forever.  I have already
>reworked things to use strerror_r "consistently"; I also cleaned up things
>by not using STRERROR() at all where its result is simply ignored.
>If it is acceptable, I can commit it (and undergo review and further 
>cleanup,
>of course).
>
>p.
>
>
>
>
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