tstop
signal(SIGTSTP, tstop);
signal(SIGSTOP, tstop);
static void tstop(int);
signal(SIGTSTP, tstop);
struct timeval tstop;
(void)gettimeofday(&tstop, NULL);
delta = ((tstop.tv_sec*10.)+(tstop.tv_usec/100000)) -