Add quit and daemon quit commands

Add default keys CTRL+q to post a "quit" command and listen for the
command in the Game::respond function. When the SHIFT key is also
pressed on Linux, run a system command that stops the daemon configured
at "daemon service name". This is made for arcade cabinet builds which
have a daemon service managing the game.

src/Configuration.cpp

@@ -29,7 +29,8 @@ void Configuration::set_defaults()
         {"down", "down"},
         {"left", "left"},
         {"fullscreen", {"ALT", "enter"}},
-        {"reset", {"CTRL", "r"}}
+        {"reset", {"CTRL", "r"}},
+        {"quit", {"CTRL", "q"}}
     };
     config["input"] = {
         {"suppress any key on mods", true},
@@ -43,7 +44,7 @@ void Configuration::set_defaults()
         {"max framerate", -1},
         {"vsync", false},
         {"sdl delay", 6},
-        {"title", "play your next game at dank.game 🪐💫💫💫📦"},
+        {"title", "🚬 dank🦄game 🚬"},
         {"debug", false},
         {"show cursor", false},
         {"render-test-spacing", 2},
@@ -104,13 +105,14 @@ void Configuration::set_defaults()
     config["configuration"] = {
         {"auto refresh", false},
         {"auto refresh interval", 5.0},
-        {"android config path", "config_android.json"},
-        {"wasm config path", "config_wasm.json"},
         {"search path", {"config.json", "config"}}
     };
     config["storage"] = {
         {"preferences file", "storage/preferences.json"}
     };
+    config["system"] = {
+        {"daemon service name", ""}
+    };
 }
 
 nlohmann::json& Configuration::operator[](const std::string& key)

src/Game.cpp

@@ -656,6 +656,63 @@ std::shared_ptr<TTF_Font> sb::Game::font(
 
 void Game::respond(SDL_Event& event)
 {
+    /* Game will quit after current frame */
+    if (_delegate.compare(event, "quit"))
+    {
+        flag_to_end();
+
+#if defined(__LINUX__)
+        /* If the shift button is being held and the game is configured to have a systemd service file path, add a
+         * system call to stop the service. This prevents the service from automatically relaunching the game after
+         * it quits. */
+        std::string daemon_name { configuration()("system", "daemon service name") };
+        if (!daemon_name.empty() && SDL_GetModState() & KMOD_SHIFT)
+        {
+            /* Make sure the service name has no special characters. This prevents system commands from being inserted
+             * through the configuration. */
+            std::string invalid_characters { " ~`!@#$%^;\"'<>,.?{}[]|\\&*()+=" };
+            if (strcspn(daemon_name.c_str(), invalid_characters.c_str()) == daemon_name.size())
+            {
+                /* Check if a command processor exists */
+                if (std::system(nullptr) > 0)
+                {
+
+                    /* Build systemctl command */
+                    std::ostringstream command;
+                    command << "systemctl --user stop " << daemon_name;
+
+                    /* To run successfully, this requires a systemd service to be running. */
+                    int status = std::system(command.str().c_str());
+                    sb::Log::Multi() << "Stopping systemd service " << daemon_name << sb::Log::end;
+                    if (WIFEXITED(status) == 0)
+                    {
+                        if (WIFSIGNALED(status) == 0)
+                        {
+                            if (WIFSTOPPED(status) > 0)
+                            {
+                                sb::Log::Multi() << "Daemon stopped with signal " << WTERMSIG(status) << sb::Log::end;
+                            }
+                        }
+                        else
+                        {
+                            sb::Log::Multi() << "Daemon terminated with signal " << WTERMSIG(status) << sb::Log::end;
+                        }
+                    }
+                    else
+                    {
+                        sb::Log::Multi() << "Daemon exit status is " << WEXITSTATUS(status) << sb::Log::end;
+                    }
+                }
+            }
+            else
+            {
+                sb::Log::Multi() << "Daemon name " << daemon_name << " contains invalid characters." << sb::Log::end;
+            }
+        }
+    }
+#endif
+
+    /* Controls for the recorder object */
     if (configuration()("recording", "enabled"))
     {
         if (_delegate.compare(event, "screenshot"))

src/Game.hpp

@@ -20,6 +20,12 @@
 #include <functional>
 #include <optional>
 
+/* Needed to make system calls and check exit status of Linux processes */
+#if defined(__LINUX__)
+#include <sys/wait.h>
+#include <string.h>
+#endif
+
 #include "SDL.h"
 #include "SDL_mixer.h"
 #include "SDL_ttf.h"

src/Input.cpp

@@ -106,7 +106,10 @@ void Input::respond(SDL_Event &event)
         {
             for (KeyCombination& combination : key_map)
             {
-                if (sym == combination.key && (!combination.ctrl || ctrl) && (!combination.shift || shift) && (!combination.alt || alt))
+                if (sym == combination.key &&
+                    (!combination.ctrl || ctrl) &&
+                    (!combination.shift || shift) &&
+                    (!combination.alt || alt))
                 {
                     sb::Delegate::post(combination.command, cancel);
                     if (!sb::contains(system_any_key_ignore, combination.command) && !found_command &&