Example of crazy use of multiple calls to main() and cli args.

main.c

/*
 * Maybe this should be illegal? This is a program that RETURNS the factorial of
 * the number of cli args it receives, by recursivelly calling main.
 *
 * License: The Unlicense License
 * Original author: Gabriel G. de Brito
 */

int main(int argc, char *argv[])
{
	if (argc == 0)
		return 1;
	return argc * main(argc - 1, argv);
}