Command-Line Arguments in C

Introduction

Command-line arguments are a way to pass parameters to a C program when it's executed in a command-line environment. They allow users to customize the behavior of a program without modifying the source code. In this guide, we'll explore how to work with command-line arguments in C and provide sample code to illustrate their usage.

Command-Line Arguments

Command-line arguments are typically passed to a C program when it's run from the terminal. They are stored as strings and can be accessed from the program's main() function. The common format for running a C program with command-line arguments is:

        ./program_name arg1 arg2 arg3 ...

Accessing Command-Line Arguments

In C, the command-line arguments are passed to the main() function as parameters. The first parameter, argc, represents the number of arguments, and the second parameter, argv, is an array of strings containing the arguments. Here's how you can access them:

        int main(int argc, char *argv[]) {
            // argc is the argument count
            // argv is the argument vector (array of strings)
            
            // Access and process command-line arguments
            for (int i = 1; i < argc; i++) {
                printf("Argument %d: %s\\n", i, argv[i]);
            }
            
            return 0;
        }

Sample Code

Let's explore some examples of working with command-line arguments in C:

Printing Command-Line Arguments

        #include <stdio.h>
        int main(int argc, char *argv[]) {
            // Print all command-line arguments
            for (int i = 1; i < argc; i++) {
                printf("Argument %d: %s\\n", i, argv[i]);
            }
            return 0;
        }

Calculating the Sum of Numbers

        #include <stdio.h>
        #include <stdlib.h>
        int main(int argc, char *argv[]) {
            if (argc < 2) {
                printf("Usage: %s num1 num2 ...\\n", argv[0]);
                return 1;
            }
            int sum = 0;
            for (int i = 1; i < argc; i++) {
                sum += atoi(argv[i]);
            }
            printf("Sum of numbers: %d\\n", sum);
            return 0;
        }

Conclusion

Command-line arguments are a powerful feature in C programming, allowing users to customize program behavior without altering the source code. This guide has introduced you to the basics of working with command-line arguments in C, including accessing arguments and providing sample code for printing arguments and calculating the sum of numbers. As you continue your C programming journey, you'll find command-line arguments to be a valuable tool for creating versatile and user-friendly applications.

Command-Line Arguments in C

Command-Line Arguments in C

Introduction