It is possible to run one installer by user at a time

locale/ubinstall-gtk.pot

@@ -5352,3 +5352,6 @@ msgstr ""
 
 msgid "Close installer"
 msgstr ""
+
+msgid "Application is already running"
+msgstr ""

locale/ubinstall-gtk_ru.po

@@ -5547,3 +5547,6 @@ msgstr "Снять всё"
 
 msgid "Close installer"
 msgstr "Закрыть установщик"
+
+msgid "Application is already running"
+msgstr "Приложение уже запущено"

source/ubinstall-gtk.c

@@ -1028,6 +1028,10 @@ main_window *yon_main_window_complete(){
 }
 
 int main(int argc, char *argv[]){
+    GApplication *app = (GApplication*)gtk_application_new("com.ublinux.ubinstall-gtk",G_APPLICATION_DEFAULT_FLAGS);
+    GError *err = NULL;
+    int reg = g_application_register(app,NULL,&err);
+    int remote = g_application_get_is_remote(app);
     main_config.argv=argv;
     main_config.argc = argc;
 	config_str unfound = NULL;
@@ -1037,6 +1041,25 @@ int main(int argc, char *argv[]){
     textdomain(LocaleName);
     config_init();
     gtk_init(&argc,&argv);
+
+    if (!reg||remote){
+        yon_window *window = yon_window_new();
+        gtk_widget_set_size_request(window->Window,300,125);
+        yon_gtk_window_setup(GTK_WINDOW(window->Window),NULL,WARNING_TITLE_LABEL,icon_path,NULL);
+        GtkWidget *box = gtk_box_new(GTK_ORIENTATION_HORIZONTAL,5);
+        GtkWidget *image = gtk_image_new();
+        GtkWidget *label = gtk_label_new(ALREADY_RUNNING_LABEL);
+        gtk_image_set_from_icon_name(GTK_IMAGE(image),warning_icon_path,0);
+        gtk_image_set_pixel_size(GTK_IMAGE(image),48);
+        gtk_box_pack_start(GTK_BOX(box),image,1,1,0);
+        gtk_box_pack_start(GTK_BOX(box),label,1,1,0);
+        gtk_box_pack_start(GTK_BOX(window->MainBox),box,1,1,0);
+        gtk_widget_show_all(box);
+        g_signal_connect(G_OBJECT(window->Window),"destroy",G_CALLBACK(gtk_main_quit),NULL);
+        gtk_widget_show(window->Window);
+        gtk_main();
+        exit(1);
+    }
     yon_ubl_window_init(TITLE_LABEL,"",LocaleName,CssPath,LocaleName,version_application,WIKI_LINK);
 	yon_ubl_setup_arguments(argc,argv,&unfound,&size,ADDITIONAL_ARGS);
     if (size) {

source/ubinstall-gtk.h

@@ -50,6 +50,7 @@
 #define active_icon_path "com.ublinux.libublsettingsui-gtk3.active-symbolic"
 #define inactive_icon_path "com.ublinux.libublsettingsui-gtk3.inactive-symbolic"
 #define info_icon_path "com.ublinux.libublsettingsui-gtk3.important-symbolic"
+#define warning_icon_path "com.ublinux.libublsettingsui-gtk3.warning-symbolic"
 
 #define LocalePath "/usr/share/locale"
 #define LocaleName "ubinstall-gtk"

source/ubl-strings.h

@@ -304,6 +304,7 @@ NULL)
 #define ACCESSED_LABEL _("Accessed")
 #define UNACCESSED_LABEL _("Unaccessed")
 #define INFO_LABEL _("Package information")
+#define ALREADY_RUNNING_LABEL _("Application is already running")
 
 // #define _LABEL _("Chosen size:")
 // #define _LABEL _("Overall size:")