extract main kakoune code to a kakoune function

src/main.cc

@@ -174,22 +174,11 @@ void signal_handler(int signal)
     abort();
 }
 
-int main(int argc, char* argv[])
+int kakoune(memoryview<String> params)
 {
-    try
+    ParametersParser parser(params, { { "c", true },
-    {
+                                      { "e", true },
-        setlocale(LC_ALL, "");
+                                      { "n", false } });
-
-        signal(SIGSEGV, signal_handler);
-        signal(SIGFPE,  signal_handler);
-        signal(SIGQUIT, signal_handler);
-        signal(SIGTERM, signal_handler);
-
-        std::vector<String> params;
-        for (size_t i = 1; i < argc; ++i)
-             params.push_back(argv[i]);
-        ParametersParser parser(params, { { "c", true }, { "e", true }, { "n", false } });
-        EventManager event_manager;
 
     String init_command;
     if (parser.has_option("e"))
@@ -197,8 +186,17 @@ int main(int argc, char* argv[])
 
     if (parser.has_option("c"))
     {
+        for (auto opt : { "n" })
+        {
+            if (parser.has_option(opt))
+            {
+                fprintf(stderr, "error: -%s makes not sense with -c", opt);
+                return -1;
+            }
+        }
         try
         {
+            EventManager event_manager;
             auto client = connect_to(parser.option_value("c"),
                                      std::unique_ptr<UserInterface>{new NCursesUI{}},
                                      init_command);
@@ -207,11 +205,14 @@ int main(int argc, char* argv[])
         }
         catch (peer_disconnected&)
         {
-                puts("disconnected");
+            fputs("disconnected from server", stderr);
+            return -1;
         }
         return 0;
     }
-
+    else
+    {
+        EventManager        event_manager;
         GlobalOptions       global_options;
         GlobalHooks         global_hooks;
         ShellManager        shell_manager;
@@ -284,6 +285,26 @@ int main(int argc, char* argv[])
             Context empty_context;
             global_hooks.run_hook("KakEnd", "", empty_context);
         }
+        return 0;
+    }
+}
+
+int main(int argc, char* argv[])
+{
+    try
+    {
+        setlocale(LC_ALL, "");
+
+        signal(SIGSEGV, signal_handler);
+        signal(SIGFPE,  signal_handler);
+        signal(SIGQUIT, signal_handler);
+        signal(SIGTERM, signal_handler);
+
+        std::vector<String> params;
+        for (size_t i = 1; i < argc; ++i)
+             params.push_back(argv[i]);
+
+        kakoune(params);
     }
     catch (Kakoune::exception& error)
     {