added config class

src/Makefile

@@ -18,10 +18,12 @@ OBJS=\
 	cmd-frontend.o \
 	coap-frontend.o \
 	avahi-service.o \
+	config.o \
 	
 TARGETS=\
 	desk-main \
-	avahi-test \
+	config-test \
+	#avahi-test \
 
 all: $(TARGETS)
 

src/config-test.cpp

+/*
+ * config-test.cpp
+ *
+ *  Created on: 11.10.2017
+ *      Author: geith
+ */
+
+
+#include "config.h"
+
+#include <iostream>
+#include <unistd.h>
+
+using namespace std;
+using namespace desk;
+
+int main(int argc, char** argv){
+	Config conf("test.conf");
+
+	try{
+		cout << "key_1 -> " << conf.get("key_1") << endl;
+	} catch(ConfigException& e){
+		cout << e.what() << endl;
+	}
+	cout << "key_2 -> " << conf.get("key_2", "default_value") << endl;
+	cout << "key_3 -> " << conf.get("key_3", "default_value") << endl;
+	cout << "key_4 -> " << conf.get("key_4", "default_value") << endl;
+
+	conf.set("key_4", "val_4");
+
+	return 0;
+}

src/config.cpp

+/*
+ * config.cpp
+ *
+ *  Created on: 11.10.2017
+ *      Author: geith
+ */
+
+#include "config.h"
+
+#include <fstream>
+#include <iostream>
+#include <sstream>
+
+using namespace std;
+using namespace desk;
+
+Config::Config(const string file):
+		m_configFile(file)
+{
+	readFile();
+}
+
+void
+Config::readFile()
+{
+	ifstream in(m_configFile);
+	if(in.fail()){
+		// could not open config file
+		return;
+	}
+
+	string line;
+
+	while(!in.eof() && !in.fail()){
+		getline(in, line);
+
+		cout << __func__ << ": got line \"" << line << "\"" << endl;
+
+		if(line.empty()){
+			continue;
+		}
+
+		istringstream l_in(line);
+		string key;
+		string value;
+
+		l_in >> key >> value;
+
+		cout << __func__ << ": key=" << key << ", value=" << value << endl;
+		m_config[key] = value;
+	}
+
+	in.close();
+}
+
+
+void
+Config::writeFile() throw(ConfigException)
+{
+	ofstream out(m_configFile);
+	if(out.fail()){
+		// could not open config file
+		throw ConfigException("could not write file");
+	}
+
+	for(auto c: m_config){
+		out << c.first << " " << c.second << endl;
+	}
+
+	out.close();
+}
+
+std::string
+Config::get(const std::string& key) throw(ConfigException)
+{
+	try{
+		return m_config.at(key);
+	} catch(out_of_range& e){
+		throw ConfigException("key \"" + key + "\" not found");
+	}
+}
+
+std::string
+Config::get(const std::string& key, const std::string& default_value)
+{
+	try{
+		return m_config.at(key);
+	} catch(out_of_range& e){
+		return default_value;
+	}
+}
+
+void
+Config::set(const std::string& key, const std::string& value)
+{
+	m_config[key] = value;
+	writeFile();
+}

src/config.h

+/*
+ * config.h
+ *
+ *  Created on: 11.10.2017
+ *      Author: geith
+ */
+
+#ifndef CONFIG_H_
+#define CONFIG_H_
+
+#include <string>
+#include <map>
+
+namespace desk{
+
+class ConfigException: public std::exception{
+public:
+	ConfigException(std::string msg) _GLIBCXX_USE_NOEXCEPT
+			: m_msg(msg){ }
+
+		virtual const char* what()
+			const  _GLIBCXX_USE_NOEXCEPT{
+
+		return m_msg.c_str();
+	}
+
+protected:
+	std::string m_msg;
+};
+
+class Config{
+public:
+	Config(const std::string file);
+
+	std::string get(const std::string& key) throw(ConfigException);
+	std::string get(const std::string& key, const std::string& default_value);
+
+	void set(const std::string& key, const std::string& value);
+
+protected:
+	void readFile();
+	void writeFile() throw(ConfigException);
+
+	const std::string m_configFile;
+	std::map<std::string,std::string> m_config;
+};
+
+}
+
+#endif /* CONFIG_H_ */