/* Primes finder (primes.c) by Cobi */

/*
 * We need this library (printf?).
 */
#include <stdio.h>

/*
 * We need this library for atoi().
 */
#include <stdlib.h>

int main (int argc, char **argv) { /* Our main program. */
	/* Make sure we have the correct arguementes. */
	if (argc < 2) {
		/* We don't, complain. */
		printf ("This binary requires the start");
		printf ("and stop values as arguements 1 ");
		printf ("and 2.\nExample: %s <start> <st",argv[0]);
		printf ("op>\n");
		return 0;
	}

	/* We initialize our outer loop variables. */
	unsigned long bigcounter = atoi(argv[1]);
	unsigned long upperbound = atoi(argv[2]);

	/* Then we initialize our inner loop variables. */
	unsigned long to = 0;
	unsigned long counter = 0;
	unsigned long halfto = 0;

	/*
	 * And then we initialize our variable to
	 * hold the status of the current check.
	 */
	unsigned short found = 0;

	/*
	 * We make a big loop through each integer
	 * between argv[1] and argv[2].
	 */
	while (bigcounter <= upperbound) {
		/* Reset any variables for the inner loop. */
		counter = 2;
		to = bigcounter;
		found = 0;
		halfto = to / 2;
		/*
		 * We make an inner loop to loop through
		 * each integer between 2 and half of the
		 * integer we are checking for primality.
		 */
		while (counter < halfto) {
			/*
			 * We check to see if the counter devides
			 * evenly into the integer we are checking
			 * for primality.
			 */
			if (to % counter == 0) {
				/* It is not prime, set found = 1 */
				found = 1;
				/* and set counter so the loop exits. */
				counter = to;
			}
			/* Increment the counter. */
			counter++;
		}
		/*
		 * Check to see if the loop exited normally
		 * as opposed to prematurely.
		 */
		if (found == 0) {
			/*
			 * If it exited normally, we found
			 * ourselves a prime!  Print it out
			 * so the owner can see.
			 */
			printf("%d\n",to);
		}
		/* Increment the counter. */
		bigcounter++;
	}
	/* Exit successfully. */
	return 0;
}