C Command Line Arguments

Command line arguments allow programs to accept input from the command line.

1. main Function with Arguments

int main(int argc, char *argv[]) {
    // argc: argument count
    // argv: argument vector (array of strings)
    return 0;
}

2. Basic Usage

#include <stdio.h>

int main(int argc, char *argv[]) {
    printf("Number of arguments: %d\n", argc);
    
    for (int i = 0; i < argc; i++) {
        printf("Argument %d: %s\n", i, argv[i]);
    }
    
    return 0;
}

3. Example Usage

$ ./program arg1 arg2 arg3
Number of arguments: 4
Argument 0: ./program
Argument 1: arg1
Argument 2: arg2
Argument 3: arg3

4. Parsing Arguments

if (argc > 1) {
    if (strcmp(argv[1], "--help") == 0) {
        printf("Usage: %s [options]\n", argv[0]);
    }
}