Re: sys_errlist deprecated? (ITS#3111)

[ando@sys-net.it]

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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