add flag handling and header guards

src/flags.cpp

@@ -0,0 +1,24 @@
+#include "const.h"
+#include <iostream>
+#include "helper_funcs.h"
+#include <cstdio>
+
+void PrintHelp() {
+    std::cout << "Usage: " << NAME << " [OPTIONS]" << "\n"
+    << "-h        Show this help menu\n"
+    << "-V        Show version\n"
+    << "-v        verbose mode\n"
+    << "-L        Force new login\n"
+    << "-S        Ignore SSL cert validity\n";
+    safe_exit(0);
+  }
+  
+void PrintVersion() {
+    std::cout << NAME" " << VERSION"\n" << "License GPLv3: GNU GPL version 3 <https://gnu.org/licenses/gpl.html>.\n";
+    safe_exit(0);
+  }
+
+void DeleteLogin(std::string savedir_path) {
+    std::remove((savedir_path + "/authfile").c_str());
+    std::remove((savedir_path + "/urlfile").c_str());
+}