#include <stdio.h>
#include <unistd.h> // fork, sleep
#include <stdlib.h> // exit
#include <sys/wait.h> // wait

int main(){
    int status;
    int pid;

    if ((pid = fork()) == 0) {
        printf("I'm the son and going to sleep for 30s.\n");
        sleep(30);
        exit(3);
    } 
    else if (pid == -1) {
        printf("fork() failed");
        exit(2);
    }

    wait(&status);

    printf("wait status 0x%x | 0x%x | 0x%x\n", status, (status>>8) & 0xff, status & 0xff);
    return 0;
}