How to Parse Command Line Arguments in C++?

In C++, command line arguments are parameters that are passed to a program when it is invoked via command line or terminal. In this article, we will learn how to parse command line arguments in C++.

Parse Command Line Arguments in C++

In C++, we can parse the command-line arguments using the argc and argv[] parameters that are passed to the main function.

• argc represents the number of command line arguments passed to the program,
• argv is an array of C-style strings (character arrays) containing the actual arguments.

We can use loops to iterate and parse the command line arguments stored inside the argv array.

C++ Program to Parse Command Line Arguments

C++

// C++ Program to illustrate how to Parse Command Line
// Arguments
#include <iostream>
using namespace std;

int main(int argc, char* argv[])
{
    cout << "You have entered " << argc
         << " arguments:" << endl;

    // Using a while loop to iterate through arguments
    int i = 0;
    while (i < argc) {
        cout << "Argument " << i + 1 << ": " << argv[i]
             << endl;
        i++;
    }

    return 0;
}

Input:

./program1 this is something

Output:

You have entered 4 arguments:
Argument 1: ./program1.out
Argument 2: this
Argument 3: is
Argument 4: something