w_stopval
#define WIFSTOPPED(x) ((x).w_stopval == WSTOPPED)
#define WIFSIGNALED(x) ((x).w_stopval != WSTOPPED && (x).w_termsig != 0)
#define WIFEXITED(x) ((x).w_stopval != WSTOPPED && (x).w_termsig == 0)
# define WIFEXITED(s) (((union wait*)&(s))->w_stopval != WSTOPPED && \