🔴 Advanced · Lesson 44

Command Line Arguments

Command line arguments are values passed to a program when it starts. They allow the same program to work with different inputs without asking through scanf().

argc and argv

Syntax

int main(int argc, char *argv[]) {
    // argc = number of arguments
    // argv = array of argument strings
}

Print Arguments

C Language

#include <stdio.h>

int main(int argc, char *argv[]) {
    printf("Total arguments = %d\n", argc);

    for(int i = 0; i < argc; i++) {
        printf("argv[%d] = %s\n", i, argv[i]);
    }
    return 0;
}

Command: ./app hello c Total arguments = 3 argv[0] = ./app argv[1] = hello argv[2] = c

Sum Program

C Language

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

int main(int argc, char *argv[]) {
    if(argc != 3) {
        printf("Usage: ./sum num1 num2");
        return 1;
    }

    int a = atoi(argv[1]);
    int b = atoi(argv[2]);
    printf("Sum = %d", a + b);
    return 0;
}

Command: ./sum 10 20 Sum = 30

Summary

argc stores number of arguments
argv stores argument strings
argv[0] is usually program name
Use atoi() or similar functions to convert strings to numbers
Command line arguments are useful for tools and automation

Command Line Arguments

Command line arguments program start करते समय दिए जाने वाले values होते हैं। इससे program अलग-अलग input के साथ run हो सकता है।

argc और argv

C Language

int main(int argc, char *argv[]) {
    // argc = arguments की संख्या
    // argv = argument strings का array
}

Example

C Language

for(int i = 0; i < argc; i++)
    printf("%s\n", argv[i]);

Sum Program

C Language

int a = atoi(argv[1]);
int b = atoi(argv[2]);
printf("Sum = %d", a + b);

सारांश

argc arguments की संख्या बताता है
argv arguments strings का array है
argv[0] generally program name होता है
String को number में बदलने के लिए atoi use कर सकते हैं
Tools और automation में useful है

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