From c522196d669e45d171ee128c276053ef755c2ad3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=A1s=20A=2E=20Ortega?=
 <deathsbreed@themusicinnoise.net>
Date: Wed, 14 Dec 2016 17:52:52 +0100
Subject: [PATCH] Argument parsing!

---
 src/main.c | 65 +++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 55 insertions(+), 10 deletions(-)

diff --git a/src/main.c b/src/main.c
index 96ccdf5..4702f84 100644
--- a/src/main.c
+++ b/src/main.c
@@ -2,21 +2,58 @@
 #include <stdlib.h>
 #include <signal.h>
 #include <stdbool.h>
+#include <getopt.h>
 #include <gmp.h>
 
 #include "list.h"
 
+#define VERSION "v0.5"
+
 static bool run;
 
+void printUsage(char *progName);
 void leave();
 
-int main(void) {
-	puts("Indivisible v0.5\n");
+int main(int argc, char *argv[]) {
+	bool f_help = false, f_version = false, f_quiet = false;
+
+	int c;
+	while((c = getopt(argc, argv, "hvq")) != -1) {
+		switch(c) {
+			case 'h':
+				f_help = true;
+				break;
+			case 'v':
+				f_version = true;
+				break;
+			case 'q':
+				f_quiet = true;
+				break;
+			default:
+				printUsage(argv[0]);
+				exit(1);
+		}
+	}
+
+	if(f_help) {
+		printUsage(argv[0]);
+		puts(" -h     print this help information");
+		puts(" -v     print version number of program");
+		puts(" -q     quiet mode");
+		return 0;
+	} else if(f_version) {
+		printf("Indivisible %s\n", VERSION);
+		return 0;
+	}
 
 	// Quit on ^C by setting `run = false'
 	run = true;
 	signal(SIGINT, leave);
 
+	if(f_quiet) {
+		puts("Use Ctrl+C (SIGINT) to exit.");
+	}
+
 	// Primes we've found
 	List primes;
 	initList(&primes);
@@ -28,11 +65,13 @@ int main(void) {
 	// Add 2, a known prime to this list
 	mpz_set_ui(num, 2);
 	addToList(&primes, num);
-	if(mpz_out_str(stdout, 10, num) == 0) {
-		fprintf(stderr, "Could not print to `stdout'!\n");
-		exit(1);
+	if(!f_quiet) {
+		if(mpz_out_str(stdout, 10, num) == 0) {
+			fprintf(stderr, "Could not print to `stdout'!\n");
+			exit(1);
+		}
+		printf("\n");
 	}
-	printf("\n");
 	mpz_add_ui(num, num, 1);
 
 	// Variable for half `num'
@@ -54,11 +93,13 @@ int main(void) {
 
 		// `num' is a prime so we add it to the list and print it
 		addToList(&primes, num);
-		if(mpz_out_str(stdout, 10, num) == 0) {
-			fprintf(stderr, "Could not print to `stdout'!\n");
-			exit(1);
+		if(!f_quiet) {
+			if(mpz_out_str(stdout, 10, num) == 0) {
+				fprintf(stderr, "Could not print to `stdout'!\n");
+				exit(1);
+			}
+			printf("\n");
 		}
-		printf("\n");
 
 nextPrime:
 		// Add 2 (skip even numbers since they're all divisible by 2)
@@ -77,4 +118,8 @@ nextPrime:
 	return 0;
 }
 
+void printUsage(char *progName) {
+	printf("%s [-v | -h | -q]\n", progName);
+}
+
 void leave() { run = false; }