Function freopen

examples/stdlib.c:3305–3342

}

static FILE *freopen(const char *path, const char *mode, FILE *stream)
{
    int flags = stdio_parse_mode(mode);
    if (flags < 0)
    {
        fclose(stream);
        errno = EINVAL;
        return NULL;
    }
    int fd = open(path, flags,
        S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
    if (fd < 0)
    {
        fclose(stream);
        return NULL;
    }
    int old_fd = -1;
    bool r = ((flags & O_ACCMODE) != O_WRONLY? true: false);
    bool w = ((flags & O_ACCMODE) != O_RDONLY? true: false);
    flags = (r? STDIO_FLAG_READ: 0) | (w? STDIO_FLAG_WRITE: 0);
    if (mutex_lock(&stream->mutex) < 0)
    {
        close(fd);
        return NULL;
    }
    (void)fflush_unlocked(stream);    // Ignore errors
    old_fd         = stream->fd;
    stream->fd     = fd;
    stream->flags &= ~(STDIO_FLAG_READ | STDIO_FLAG_WRITE |
                       STDIO_FLAG_READING | STDIO_FLAG_WRITING |
                       STDIO_FLAG_EOF | STDIO_FLAG_ERROR);
    stream->flags |= flags;
    stream->read_ptr = stream->read_end = NULL;
    stream->write_ptr = stream->write_end = NULL;
    mutex_unlock(&stream->mutex);
    (void)close(old_fd);                    // Ignore errors
    return stream;
}

static void clearerr_unlocked(FILE *stream)
{