#include<sys/types.h>
#include<iostream>
#include<unistd.h>
#include<wait.h>

int main(){

  pid_t pid;

  /* fork a child process */
  pid = fork();

  if (pid < 0){  // error
    cerr << "Fork failed\n";
    exit(-1);
  }
  else if (pid == 0){ // child process
    // cout << "Child process\n";
    execlp("/bin/ls","ls",NULL);
    cout << "Child process\n";
  }
  else{ // parent process
    // parent will wait for child to complete
    wait(NULL);
    //   cout << "Child Complete\n";
    execlp("/bin/ls","ls",NULL);
    cout << "done!\n";
    exit(0);
  }
}