// C version of a Prime Number Finder
// haplo@mindstab.net

#include <stdlib.h>
#include <stdio.h>
#include <math.h>

int main(int argc, char ** argv)
{
	unsigned int counter, max_test, tester;
	char isPrime;
	unsigned int MAX_NUM;
	
	if(argc < 2) {
		printf("primesc <MAX NUM>\n");
		return 1;
	} else {
		MAX_NUM = atoi(argv[1]);
	}
	if(MAX_NUM < 1)
	{
		printf("Invalid MAX_NUM specified\n");
		return 1;
	}

	for(counter =3; counter<= MAX_NUM; counter +=2)
	{
		max_test = (int) sqrt((double) counter);
		isPrime = 1;

		for(tester =3; tester <= max_test;  tester += 2)
		{
			if(! (counter % tester)) {
				isPrime = 0;
				break;
			}
		}
		if(isPrime) printf("%d\n", counter);
	}
	return 0;
}