Class sigaction

sys/unix/unixmain.c:598–598

     * succeeds (or the stream returns EOF, which might not happen if
     * reading from, say, a window manager). */
    struct sigaction sact;

    (void) memset((genericptr_t) &sact, 0, sizeof sact);
    sact.sa_handler = (SIG_RET_TYPE) handler;