Command-Line Arguments in C

Command-Line Arguments in C — a practical guide to C argc argv with clear examples you can reuse in real projects.

C Programming Tutorial Series (84/102). Prefer one article? Read the complete C programming tutorial.

Short description

argv[0] is the program name; validate argc before using argv[i].

argc/argv

int main(int argc, char *argv[]) {
    if (argc < 2) {
        printf("Usage: %s <file>n", argv[0]);
        return 1;
    }
    printf("File: %sn", argv[1]);
    return 0;
}