unix_path

static VALUE
addrinfo_unix_path(VALUE self)
{
    rb_addrinfo_t *rai = get_addrinfo(self);
    int family = ai_get_afamily(rai);
    struct sockaddr_un *addr;
    char *s, *e;

    if (family != AF_UNIX)
        rb_raise(rb_eSocket, "need AF_UNIX address");

    addr = &rai->addr.un;

    s = addr->sun_path;
    e = (char*)addr + rai->sockaddr_len;
    if (e < s)
        rb_raise(rb_eSocket, "too short AF_UNIX address: %"PRIuSIZE" bytes given for minimum %"PRIuSIZE" bytes.",
            (size_t)rai->sockaddr_len, (size_t)(s - (char *)addr));
    if (addr->sun_path + sizeof(addr->sun_path) < e)
        rb_raise(rb_eSocket,
            "too long AF_UNIX path (%"PRIuSIZE" bytes given but %"PRIuSIZE" bytes max)",
            (size_t)(e - addr->sun_path), sizeof(addr->sun_path));
    while (s < e && *(e-1) == '\0')
        e--;
    return rb_str_new(s, e-s);
}