wrapper.c

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <inttypes.h>

extern uint64_t collatz(uint64_t);

int main(int argc, char* argv[]) {
	if(argc < 2) {
		fputs("Not enough arguments!\n", stderr);
		return EXIT_FAILURE;
	}

	char* test = NULL;
	uint64_t val = strtoull(argv[1], &test, 10);
	if(*test) {
		fprintf(stderr,"Invalid Argument: %s\n", argv[1]);
		return EXIT_FAILURE;
	}

	uint64_t res = collatz(val);
	printf("collatz(%"PRIu64") = %"PRIu64"\n", val, res);

	return EXIT_SUCCESS;
}