config file usage

main.cpp

@@ -26,8 +26,15 @@ inline std::ostream& operator<< (std::ostream &out, const app_options &opts) {
     return out << "Options: { "
                << "config-file: " <<  opts.config_file << ", "
                << "initial-pin-state: " <<  opts.initial_pin_state << " }";
+}
 
-    
+inline std::ostream& operator<< (std::ostream &out, const std::ifstream &input) {
+    std::string line;
+    while (std::getline(const_cast<std::ifstream &>(input), line).good()) {
+        out << line << std::endl;
+    }
+
+    return out;
 }
 
 int main(int argc, char** argv) {
@@ -36,13 +43,21 @@ int main(int argc, char** argv) {
     el::Loggers::addFlag(el::LoggingFlag::ColoredTerminalOutput);
 
     app_options opts = parse_opts(argc, argv);
+    LOG(INFO) << opts;
+
     if(opts.config_file.empty()) {
         LOG(WARNING) << "Config file is not set! So we use hardcoded configuration:" << std::endl
                      << schedule.str();
+    } else {
+        std::ifstream input{opts.config_file};
+        LOG(INFO) << "Config file:" << std::endl << input;
     }
 
-    LOG(INFO) << opts;
-    TaskManager manager{schedule, digitalWrite};
+    std::ifstream input{opts.config_file};
+    std::istream &stream = 
+        !opts.config_file.empty() && input.is_open() ? 
+            static_cast<std::istream&>(input) : static_cast<std::istream&>(schedule);
+    TaskManager manager{stream, digitalWrite};
     
     wiringPiSetup ();
     pinMode (PIN, OUTPUT);