Add --version flag to print out the current version of the application.

src/UpdaterOptions.cpp

@@ -19,6 +19,7 @@ long long atoll(const char* string)
 UpdaterOptions::UpdaterOptions()
 : mode(UpdateInstaller::Setup)
 , waitPid(0)
+, showVersion(false)
 {
 }
 
@@ -111,6 +112,7 @@ void UpdaterOptions::parse(int argc, char** argv)
 	parser.setOption("script");
 	parser.setOption("wait");
 	parser.setOption("mode");
+	parser.setFlag("version");
 
 	parser.processCommandArgs(argc,argv);
 
@@ -135,6 +137,8 @@ void UpdaterOptions::parse(int argc, char** argv)
 		waitPid = static_cast<PLATFORM_PID>(atoll(parser.getValue("wait")));
 	}
 
+	showVersion = parser.getFlag("version");
+		
 	if (installDir.empty())
 	{
 		// if no --install-dir argument is present, try parsing

src/UpdaterOptions.h

@@ -16,6 +16,7 @@ class UpdaterOptions
 		std::string scriptPath;
 		PLATFORM_PID waitPid;
 		std::string logFile;
+		bool showVersion;
 
 	private:
 		void parseOldFormatArgs(int argc, char** argv);

src/main.cpp

@@ -24,6 +24,8 @@
 
 #include <iostream>
 
+#define UPDATER_VERSION "0.4"
+
 void runWithUi(int argc, char** argv, UpdateInstaller* installer);
 
 void runUpdaterThread(void* arg)
@@ -58,6 +60,11 @@ int main(int argc, char** argv)
 	Log::instance()->open(AppInfo::logFilePath());
 	UpdaterOptions options;
 	options.parse(argc,argv);
+	if (options.showVersion)
+	{
+		std::cout << "Update installer version " << UPDATER_VERSION << std::endl;
+		return 0;
+	}
 
 	UpdateInstaller installer;
 	UpdateScript script;