rem: for (i=0;i<num_pids;i++) { if (all_pids[i] != getpid()) kill(all_pids[i], sig);
add: for (i = 0; i < num_pids; i++) {  pid_t p = all_pids[i];  if (p == getpid()) continue; if (p <= 0) continue;  kill(p, sig);
context: void kill_all(int sig){	int i;	for (i=0;i<num_pids;i++) {		if (all_pids[i] != getpid())			kill(all_pids[i], sig);	}}