Make the update viewer command configurable Make the update viewer command configurable at copile time through the UPDATE_VIEWER_COMMAND macro. Make the update viewer command configurable at run time through the -c/--command command line option. Treat the update viewer command as a shell command and parse it via g_shell_parse_argv(), this allows for running the update viewer via xdg-su, gnomesu, pkexec etc. Disable install action in the notification and on the status icon in case no update viewer command has been provided.