cmdopts: Add a -?/--help option

hcore/include/opts.h

@@ -9,19 +9,19 @@
 class OptionParser
 {
 public:
-    OptionParser() : verbose(false) {}
+    OptionParser() : verbose(false), printUsage(false) {}
     ~OptionParser() = default;
 
     void parseArguments(int argc, char *argv[]);
     void dumpOptions() const;
     std::string getUsage() const;
 
-private:
+public:
     std::vector<std::string> extro;
     std::vector<std::string> intero;
     std::vector<std::string> actuator;
     std::string devFile;
-    bool verbose;
+    bool verbose, printUsage;
 
     static struct option longOptions[];
 };

hcore/opts.cpp

@@ -15,6 +15,7 @@ struct option OptionParser::longOptions[] = {
     {"devfile", required_argument, 0, 'd'},
     {"devicefile", required_argument, 0, 'd'},
     {"verbose", no_argument, 0, 'v'},
+    {"help", no_argument, 0, '?'},
     {0, 0, 0, 0}
 };
 
@@ -24,7 +25,7 @@ void OptionParser::parseArguments(int argc, char *argv[])
     int optionIndex = 0;
     optind = 1; // Reset optind to 1 before parsing
     while ((opt = getopt_long(
-        argc, argv, "e:i:a:d:v", longOptions, &optionIndex)) != -1)
+        argc, argv, "e:i:a:d:v?", longOptions, &optionIndex)) != -1)
     {
         switch (opt)
         {
@@ -43,6 +44,9 @@ void OptionParser::parseArguments(int argc, char *argv[])
         case 'v':
             verbose = true;
             break;
+        case '?':
+            printUsage = true;
+            return;
         default:
             throw std::invalid_argument("Invalid argument encountered: " + std::string(argv[optind - 1]));
         }
@@ -55,7 +59,8 @@ std::string OptionParser::getUsage() const
            "[-i|--intero|--interoceptor <sensor_dev_spec>] "
            "[-a|--act|--actuator <actuator_dev_spec>] "
            "[-d|--devfile|--devicefile <filename>] "
-           "[-v|--verbose]";
+           "[-v|--verbose] "
+           "[-?|--help]";
 }
 
 void OptionParser::dumpOptions() const

main.cpp

@@ -15,11 +15,14 @@ try {
 		options.parseArguments(argc, argv);
 	}
 	catch (const std::invalid_argument& e) {
-		std::cerr << e.what() << std::endl;
+		std::cerr << e.what() <<'\n' << options.getUsage() <<'\n';
-		std::cerr << options.getUsage() << std::endl;
 		return EXIT_FAILURE;
 	}
 
+	if (options.printUsage) {
+		std::cout << options.getUsage() << std::endl;
+		return EXIT_SUCCESS;
+	}
 	options.dumpOptions();
 }
 catch (...) {