Function vfprintf_unlocked

examples/stdlib.c:4180–4202

}

static int vfprintf_unlocked(FILE *stream, const char *format, va_list ap)
{
    va_list aq;
    va_copy(aq, ap);
    int result = vsnprintf(NULL, SIZE_MAX, format, ap);
    if (result >= 0)
    {
        ssize_t size = result+1;
        PRINTF_BUF_ALLOC(buf, size);
        if (buf != NULL)
        {
            result = vsnprintf(buf, result+1, format, aq);
            if (result >= 0)
            {
                if (fputs_unlocked(buf, stream))
                    result = -1;
            }
            PRINT_BUF_FREE(buf);
        }
    }
    va_end(aq);
    return result;
}

static int fprintf(FILE *stream, const char *format, ...)
{