Programmatically check whether my machine has internet access or not

Question

How can I programmatically check whether my machine has internet access or not using C/C++, is it just a matter of pinging an IP? How does NIC do it ? I mean something like

Answer 1

The following code will work, if you're on windows:

#include 
#include 

int main(){

  if (system("ping www.google.com")){
          std::cout<<"\nNot connnected to the internet\n\n";
  }
  else{
          std::cout<<"\nConnected to the internet\n\n";

  }
  system("pause");
  return 0;
}