#include <iostream>
#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>
#include <signal.h>
#include <sys/ptrace.h>

using namespace std;

void TellCase(int c);

int main() {

    pid_t pid;
    cout << endl;

    pid = fork();

    if (pid == 0) {
         cout << "About to stop myself " << endl;
         cout << "kill -SIGCONT " << getpid() << endl;
         raise(SIGSTOP);
        return 0;
    } else {
       bool done{false};
       while (! done) {

           int status;
           pid_t exitPid; 

           exitPid = waitpid(0, &status, WSTOPPED| WCONTINUED);

           if (exitPid == -1) {
               perror("Wait Failed");
           } else {
               cout << "A child exited " << endl;
               cout << "\tThe PID was " << exitPid 
                     << " and the fork pid was " << pid << endl;

               if (WIFEXITED(status)) {
                  int code = static_cast<int>(WEXITSTATUS(status));
                  cout << "\t Wait returned because the child was exited"
                       << endl;
                  cout  << "\t Exit staus returned ";
                  cout << code;
                  done = true;
               } else if (WIFSIGNALED(status)) {
                  int sig = WTERMSIG(status);
                  cout << "\t Wait returned because the child was signaled" 
                       << endl;
                  cout << "\t The signal was ";
                  cout << sig << endl;
                  done = true;
               } else if (WIFSTOPPED(status)) {
                  int sig = WSTOPSIG(status);
                  cout << "\t Wait returned because the child was stopped" 
                       << endl;
                  cout << "\t The stop signal was " << sig << endl;
               } else if (WIFCONTINUED(status)) {
                  cout << "\t Wait returned because the child was continued" 
                       << endl;
               } else {
                   cout << "\t unable to determine why the wait returned" 
                        << endl;
               }
          }
       }
    }

    cout << endl << endl<< endl;

    pid = fork();
    if (pid == 0) {
        cout << "Child taking a nap" << endl;
        sleep(10);
        cout << "Child going away "<< endl;
        return(0);
    } else {
        int status;
        pid_t exitPid{0};
        exitPid = waitpid(0, &status, WNOHANG);
        while (exitPid == 0) {
            cout << "Nope, it did not exit yet" << endl;
            sleep(1);
            exitPid = waitpid(0, &status, WNOHANG);
        }
    }

    cout << endl;
    return 0;
}