#include <unistd.h>
#include <stdio.h>
#include <sys/wait.h>
#include <string>
#include <iostream>
using namespace std;

int main(){
  while(1){ // loop until return
    cout << "Command (one word only)> " << flush;
    string command;
    cin >> command;
    if(command == "exit"){
      return 0;
    } else {
      pid_t returnedValue = fork();
      if(returnedValue < 0){
        perror("error forking");
        return -1;
      } else if (returnedValue == 0){
        execlp(command.c_str(), command.c_str(), NULL);
        perror(command.c_str());
        return -1;
      } else {
        if(waitpid(returnedValue, 0, 0) < 0){
          perror("error waiting for child");
          return -1;
        }
      }
    }
  }
}