#include <iostream>
#include <stdlib.h>

using namespace std;

int main(){

  char * envVar;
  envVar = getenv ("PS1");

  cout << "PS1 value is currently: " << *envVar << endl;
  cout << "We will now use putenv to change the PS1 variable" << endl;

  putenv("PS1=<duck>");

  envVar = getenv ("PS1");
  cout << "PS1 value is currently: " << *envVar << endl;
  return 0;
}