first version of settings module

src/utility/settings.h

@@ -0,0 +1,132 @@
+/*
+ * settings.h
+ *
+ *  Created on: 22.11.2012
+ *      Author: Gereon Kremer
+ */
+
+#pragma once
+
+#include <iostream>
+#include <boost/program_options.hpp>
+
+namespace mrmc {
+namespace settings {
+
+	namespace bpo = boost::program_options;
+	/*!
+	 *	@brief	Simple wrapper around boost::program_options to handle configuration options.
+	 *
+	 *	This class uses boost::program_options to read options from the
+	 *	commandline and additionally load options from a file.
+	 */
+	class Settings
+	{
+		private:
+			/*!
+			 *	@brief option descriptions
+			 */
+			bpo::options_description configfile;
+			bpo::options_description generic;
+			bpo::options_description commandline;
+			
+			/*!
+			 *	@brief collecing option descriptions
+			 *
+			 *	The options for command line and config file are collected
+			 *	here
+			 */
+			bpo::options_description cli;
+			bpo::options_description conf;
+			
+			/*!
+			 *	@brief	option mapping
+			 */
+			bpo::variables_map vm;
+		
+		public:
+		
+		/*!
+		 *	@brief Constructor of Settings file
+		 *
+		 *	The constructor fills the option descriptions, parses the
+		 *	command line and the config file and puts the option values to
+		 *	our option mapping.
+		 *
+		 *	If a configfile is set in the commandline, we load this one.
+		 *	Otherwise, if filename is not NULL, we load this one. Otherwise,
+		 *	we load no config file.
+		 *
+		 *	@param argc should be argc passed to main function
+		 *	@param argv should be argv passed to main function
+		 *	@param filename	either NULL or name of config file
+		 */
+		Settings(const int argc, const char* argv[], const char* filename)
+			: configfile("Config Options"), generic("Generic Options"), commandline("Commandline Options")
+		{
+			/*
+			 *	fill option descriptions
+			 */
+			this->commandline.add_options()
+				("help", "produce help message")
+				("help-config", "produce help message about config file")
+				("configfile", bpo::value<std::string>(), "name of config file")
+			;
+			
+			/*
+			 *	construct option descriptions for commandline and config file
+			 */
+			this->cli.add(this->commandline).add(generic);
+			this->conf.add(this->configfile).add(generic);
+			
+			try
+			{
+				/*
+				 *	load command line
+				 */
+				bpo::store(bpo::parse_command_line(argc, argv, this->cli), this->vm);
+				/*
+				 *	load config file if specified
+				 */
+				if (this->vm.count("configfile"))
+				{
+					bpo::store(bpo::parse_config_file<char>(this->vm["configfile"].as<std::string>().c_str(), this->conf), this->vm, true);
+				}
+				else if (filename != NULL)
+				{
+					bpo::store(bpo::parse_config_file<char>(filename, this->conf), this->vm, true);
+				}
+			}
+			/*
+			 *	catch errors...
+			 */
+			catch (bpo::reading_file e)
+			{
+				std::cout << "Could not read config file " << filename << std::endl;
+			}
+			catch (bpo::error e)
+			{
+				std::cout << "Some error occurred: " << e.what() << std::endl;
+			}
+			bpo::notify(this->vm);
+		}
+		
+		/*!
+		 *	@brief Get option descriptions for commandline options
+		 */
+		bpo::options_description getHelpForCommandline()
+		{
+			return this->cli;
+		}
+
+		/*!
+		 *	@brief Get option descriptions for config file options
+		 */
+		bpo::options_description getHelpForConfigfile()
+		{
+			return this->conf;
+		}
+	};
+
+} // namespace parser
+} // namespace mrmc