C++ Run External Programs

To run already existing programs on your computer header cstdlib (C Standard General Utilities Library) must be imported:

#include <iostream>
#include <cstdlib>

 Now it's easy to run, for example Windows calculator using system() function. This function help us to execute system commands:

system("calc");

And this is full source:

#include <iostream>
#include <cstdlib>

using namespace std;

int main() {

    system("calc");

    return 0;

}

Result:

It's easy to execute multiple programs with C++. Run this code and play around with other apps you have on windows.

#include <iostream>
#include <cstdlib>

using namespace std;

int main() {

    system("calc");
    system("notepad");
    system("calc");

    return 0;

}

Run External Programs with Switch Statement 

In this simple example we have information what end users need to type:

int menu = 0;

cout<< "0 for string, 1 for calc, 2 for notepad" << endl;
cout << "Please enter option: " << endl;

Then we get value with cin: 

cin >> menu;

Then switch statement with 3 options and default one:

 switch(menu) {
        case 0:
            cout << "This is just a string" << endl;
            break;
        case 1:
            system("calc");
            break;
        case 2:
            system("notepad");
            break;
        default:
            cout << "Check your input" << endl;
            break;
    }

This is full working source: 

#include <iostream>
#include <cstdlib>

using namespace std;

int main() {

    int menu = 0;

    cout<< "0 for string, 1 for calc, 2 for notepad" << endl;
    cout << "Please enter option: " << endl;
    cin >> menu;

    switch(menu) {
        case 0:
            cout << "This is just a string" << endl;
            break;
        case 1:
            system("calc");
            break;
        case 2:
            system("notepad");
            break;
        default:
            cout << "Check your input" << endl;
            break;
    }

    return 0;

}

Result when input value is 0:

0 for string, 1 for calc, 2 for notepad
Please enter option:
0
This is just a string

Process returned 0 (0x0)   execution time : 5.448 s
Press any key to continue.

Simple as that.

Now you know a lot of useful things in C++, but we will learn a lot more.