#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;
    int myCase{0};

    for(myCase = 0; myCase < 13; ++myCase) {
        cout << endl;
        TellCase(myCase);

        pid = fork();

        if (pid == 0) {
            switch (myCase) {
               case 0: return(0);
               case 1: return(1);
               case 2: return(2);
               case 3: return(3);
               case 4: return(256);
               case 5: return(257);
               case 6: raise(1); break;
               case 7: raise(9); break;
               case 8: exit(2); break;
               case 9: _exit(7); break;
               case 10: abort();
               case 11:
                   cout << "Call kill -SIGCONT " << getpid() << endl;
                   raise(SIGSTOP);
                   exit(0);
            }
            return 0;
        } else {
           bool done{false};
           while(! done) {
               pid_t exitPid; 
               siginfo_t info;

               exitPid = waitid(P_PID, pid, &info, WEXITED|WSTOPPED|WCONTINUED);

               if (exitPid == -1) {
                   perror("Wait Failed");
                   done = true;
               } else {
                   cout << "A child exited " << endl;
                   cout << "\tThe PID was " << exitPid 
                         << " and the fork pid was " << pid << endl;
                   cout << "\tThe uid was " << info.si_uid << endl;
               switch(info.si_code) {
                   case CLD_EXITED: 
                       cout << "\t Wait returned because the child was exited"
                            << endl;
                       cout  << "\t Exit staus returned ";
                       cout << info.si_status << endl;
                       done = true;
                       break;
                   case CLD_KILLED:
                      cout << "\t Wait returned because the child was signaled" 
                           << endl;
                      cout << "\tThe signal was ";
                      cout << info.si_status << endl;
                      done = true;
                      break;
                  case CLD_STOPPED:
                      cout << "\t Wait returned because the child was stopped" 
                           << endl;
                      cout << "\t The stop signal was " << info.si_signo << endl;
                      break;
                  case CLD_CONTINUED:
                     cout << "\t Wait returned because the child was continued" 
                          << endl;
                      break;
                   case CLD_DUMPED:
                      cout << "\t Wait returned because the child was dumped core" 
                          << endl;
                      done = true;
                      break;

                   default:
                      cout << "\t unable to determine why the wait returned" 
                           << endl;
               }
             }
          }
        }

    }

    cout << endl;
    return 0;
}

void TellCase(int c){
   cout << endl;
   cout << "Case " << c << endl;
   switch(c) {
       
       case 0: cout << " return(0); " << endl; break;
       case 1: cout << " return(1); " << endl; break;
       case 2: cout << " return(2); " << endl; break;
       case 3: cout << " return(3); " << endl; break;
       case 4: cout << " return(256); " << endl; break;
       case 5: cout << " return(257); " << endl; break;
       case 6: cout << " raise(1); break; " << endl; break;
       case 7: cout << " raise(9); break; " << endl; break;
       case 8: cout << " exit(2); break; " << endl; break;
       case 9: cout << " _exit(7); break; " << endl; break;
       case 10: cout << " abort(); break; " << endl; break;
       case 11: cout << " sigstop " << endl; break;
       case 12: cout << " fallthrough " << endl; break;
       default: 
          cout << "Unknown case " << endl;
   }
   cout << endl;
}