sigv
struct sigvec sigv;
(void) sigvec(SIGINT, (struct sigvec *)0, &sv.sigv);
(void) sigvec(SIGINT, &sv.sigv, (struct sigvec *)0);
sigv(cmd, sig, *argv);
sigv(argv[0], SIGSTOP, "0");
sigv(cmd, SIGSTOP, *argv);
const char *sigv = 0;
sigv = &sig->signature[0];
printf("%02x",0xff&sigv[u]);