Command-Line Arguments

main can receive the program's command-line arguments directly:

int main(int argc, char *argv[]) {
    printf("Program name: %s\n", argv[0]);
    printf("Argument count: %d\n", argc);

    for (int i = 1; i < argc; i++) {
        printf("Arg %d: %s\n", i, argv[i]);
    }
    return 0;
}

./myprogram hello world

Program name: ./myprogram
Argument count: 3
Arg 1: hello
Arg 2: world

argc counts the arguments (including the program name itself at argv[0]); argv is an array of char * strings.