Command line arguments allow programs to accept input from the command line.
int main(int argc, char *argv[]) { // argc: argument count // argv: argument vector (array of strings) return 0; }
#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; }
$ ./program arg1 arg2 arg3 Number of arguments: 4 Argument 0: ./program Argument 1: arg1 Argument 2: arg2 Argument 3: arg3
if (argc > 1) { if (strcmp(argv[1], "--help") == 0) { printf("Usage: %s [options]\n", argv[0]); } }