Index: LeahiRt/main.cpp
===================================================================
diff -u -r6f9f24886c73d92b380e4c3afd82c0b19559d42d -r0359f9239be3218d0b972a54d444e253cc3fc5d9
--- LeahiRt/main.cpp	(.../main.cpp)	(revision 6f9f24886c73d92b380e4c3afd82c0b19559d42d)
+++ LeahiRt/main.cpp	(.../main.cpp)	(revision 0359f9239be3218d0b972a54d444e253cc3fc5d9)
@@ -1,41 +1,71 @@
-#include <iostream>
+#include <signal.h>
+#include <sys/signalfd.h>
+#include <unistd.h>
+
+#include <QCommandLineOption>
+#include <QCommandLineParser>
 #include <QCoreApplication>
 #include <QDebug>
-#include <QThread>
-#include <signal.h>
+#include <QDir>
+#include <QSocketNotifier>
 
 #include "LeahiRtController.h"
 
 #define log qDebug().noquote()
 
-/*!
- * \brief       signalHandler
- * \details     When application terminates it quits gracefully.
- * \param[in]   sig - The Linux signal causes the termination.
- */
-void signalHandler(int sig)
-{
-    if (sig == SIGINT) {
-        log << "Application terminated by SIGINT";
-        qApp->quit();
-    }
-    else if (sig == SIGTERM) {
-        log << "Application terminated by SIGTERM";
-        qApp->quit();
-    }
-}
-
 int main(int argc, char *argv[])
 {
-    signal(SIGINT , signalHandler);
-    signal(SIGTERM, signalHandler);
+    // Block SIGINT and SIGTERM from normal delivery; redirect them to a fd.
+    sigset_t mask;
+    sigemptyset(&mask);
+    sigaddset(&mask, SIGINT);
+    sigaddset(&mask, SIGTERM);
+    sigprocmask(SIG_BLOCK, &mask, nullptr);
 
+    const int sfd = signalfd(-1, &mask, SFD_CLOEXEC);
+    if (sfd == -1) {
+        qCritical("Failed to create signalfd");
+        return 1;
+    }
+
     QCoreApplication app(argc, argv);
     app.setApplicationName("LeahiRt");
     app.setApplicationVersion("1.0");
 
-    LeahiRtController rtController;
-    rtController.openSocket("localhost", 80);
+    // Notifier runs on the main thread inside the event loop — safe to call quit().
+    QSocketNotifier notifier(sfd, QSocketNotifier::Read);
+    QObject::connect(&notifier, &QSocketNotifier::activated, [&](int fd) {
+        struct signalfd_siginfo info{};
+        (void)read(fd, &info, sizeof(info));
+        if (info.ssi_signo == SIGINT) {
+            log << "Application terminated by SIGINT";
+        }
+        else if (info.ssi_signo == SIGTERM) {
+            log << "Application terminated by SIGTERM";
+        }
+        app.quit();
+    });
 
+    QCommandLineParser parser;
+    parser.setApplicationDescription("Leahi Real-time Cloud Data Transmission daemon.");
+    parser.addHelpOption();
+    parser.addVersionOption();
+
+    QCommandLineOption configOption(
+        {"c", "config"}, "Path to the configuration INI file.", "config",
+        QDir(app.applicationDirPath()).filePath("config/LeahiRt.ini")
+    );
+    QCommandLineOption msgHandlingOption(
+        {"m", "msg_handling"}, "Path to the message handling INI file.", "msg_handling",
+        QDir(app.applicationDirPath()).filePath("config/LeahiRtMsgHandling.ini")
+    );
+    parser.addOption(configOption);
+    parser.addOption(msgHandlingOption);
+    parser.process(app);
+
+    LeahiRtController rtController(parser.value(configOption),
+                                   parser.value(msgHandlingOption));
+    rtController.connectToAgent();
+
     return app.exec();
 }