Command Line Arguments in C

Command Line Arguments in C! 🚢🧭🖥️

Hello, fellow code explorers! Today, we're setting sail on a voyage to uncover the secrets of using command-line arguments in C programming. Command-line arguments are like compasses that guide your code's behavior, allowing it to adapt to different scenarios. Let's embark on this journey, demystify command-line arguments, and use a practical example to understand them better! 🚀🔍📝

Understanding Command-Line Arguments

In C programming, command-line arguments are values passed to a program when it's executed in the command line or terminal. They provide a way to customize the behavior of your program without modifying the source code.

How Command-Line Arguments Work

Command-line arguments are passed to the main function as parameters. The argc parameter holds the count of arguments, and argv is an array of strings containing the actual arguments.

Here's how the main function looks:

c
int main(int argc, char *argv[]) {
    // Your code here
    return 0;
}

Accessing Command-Line Arguments

You can access command-line arguments like elements in an array. argv[0] is the name of the program itself, while subsequent elements (argv[1], argv[2], etc.) contain the arguments.

Example: A Simple Command-Line Calculator

Let's create a simple command-line calculator that takes two numbers and an operator as arguments and performs the operation.

c
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[]) {
    if (argc != 4) {
        printf("Usage: %s num1 operator num2\n", argv[0]);
        return 1;
    }

    float num1 = atof(argv[1]);
    char operator = argv[2][0];
    float num2 = atof(argv[3]);

    float result;

    switch (operator) {
        case '+':
            result = num1 + num2;
            break;
        case '-':
            result = num1 - num2;
            break;
        case '*':
            result = num1 * num2;
            break;
        case '/':
            if (num2 != 0) {
                result = num1 / num2;
            } else {
                printf("Error: Division by zero\n");
                return 1;
            }
            break;
        default:
            printf("Error: Invalid operator '%c'\n", operator);
            return 1;
    }

    printf("Result: %.2f\n", result);

    return 0;
}

In this example, we check if the number of arguments is correct (four, including the program name). Then, we parse the arguments and perform the specified arithmetic operation.

Using the Calculator

To use the calculator, compile the program and run it from the command line with three arguments: two numbers and an operator. For example:

bash
./calculator 5 + 3

This will output:

makefile
Result: 8.00

Conclusion: Charting Your Course with Command-Line Arguments

Command-line arguments are invaluable tools in C programming. They empower your programs to adapt to different scenarios without changing the source code. By understanding how to access and use command-line arguments, you open up a world of possibilities for creating versatile and user-friendly C programs. So, set sail with confidence and explore the seas of C programming! 🚢🌊🧭