How to use strerror_l with current locale?

Question

I'm fixing some Linux code which used strerror (not thread-safe) for multi-threading. I found that strerror_r and strerror_l are both thread-safe. Due to different definitions for strerror_r (depending on _GNU_SOURCE it is differently defined) I'd like to use the newer strerror_l function, but how am I supposed to obtain a locale_t object for the current locale? I'm not using iconv or anything, just plain libc, and I don't see how I can obtain a "default locale" object (I don't care in what language the error is printed, I just want a human readable string.)

Answer 1

You could use POSIX uselocale:

strerror_l(errno, uselocale((locate_t)0));

Answer 2

If you pass "" to the locale parameter newlocale will allocate a locale object set to the current native locale[1]

[1]http://pubs.opengroup.org/onlinepubs/9699919799/functions/newlocale.html

static  locale_t locale;

bool MyStrerrorInit(void)
{
    locale = newlocale(LC_CTYPE_MASK|LC_NUMERIC_MASK|LC_TIME_MASK|LC_COLLATE_MASK|
                       LC_MONETARY_MASK|LC_MESSAGES_MASK,"",(locale_t)0);

    if (locale == (locale_t)0) {
       return false;
    }

    return true;
}

char * MyStrerror(int error)
{
    return strerror_l(error, locale);
}