zombie.cpp

// A C program to demonstrate Orphan Process.
// Parent process finishes execution while the
// child process is running. The child process
// becomes orphan.
#include<stdio.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <thread>
#include <string>

using namespace std;

pid_t myPid;

pid_t makeZombie ()
{
    pid_t pid01 = fork();
    if (pid01 == 0)
    {
        pid_t pid02 = fork();
        if (pid02 == 0)
        {
            printf ("Zombie mit PID: %i\n", getpid());
            return (0);
        }
    }
    else
    {
//        int status = 0;
//        waitpid(pid01, &status, 0);
//        std::this_thread::sleep_until(std::chrono::time_point<std::chrono::system_clock>::max());
        return (pid01);
    }
    return 0;    
}

int main(int argc, char *argv[])
{
    uint msec = 500 * 1000;
    int zombies = 1;
    myPid = getpid();
    
    if (argc > 1) zombies = stoi (argv[1]);
    if (argc > 2)
    {
        zombies = stoi (argv[1]);
        msec = (stoi (argv[2]) * 1000); 
    }
    int i = 0;
    while (i<zombies)
    {
        pid_t pid = makeZombie();
        if (myPid != getpid()) return (0);

        while (waitpid(pid, 0, 0) != -1);
        
        usleep(msec);
        i++;
    }

    std::this_thread::sleep_until(std::chrono::time_point<std::chrono::system_clock>::max());
   
}