Re: No protocol specified error

[Felipe Borges <felipe10borges gmail com>]

On Fri, Oct 20, 2017 at 1:18 PM, Lokesh Chakka
<lvenkatakumarchakka gmail com> wrote:
> Dear Felipe,
>
> Thanks for the information.
> Is it possible to login with my credentials and execute as sudo ./a.out.
>
> Can u help me how to make it work ?

Running GUI applications as root is hardly discouraged.

What you should be going for is to develop an application which runs
as a normal user and uses PolicyKit[0] to gain administrator
privileges whenever is necessary.

[0] https://www.freedesktop.org/software/polkit/docs/latest/polkit.8.html

> Thanks & Regards
> --
> Lokesh Chakka,
> Mobile: 9731023458
>
> On Fri, Oct 20, 2017 at 4:43 PM, Felipe Borges <felipe10borges gmail com>
> wrote:
> > On Fri, Oct 20, 2017 at 1:01 PM, Lokesh Chakka
> > <lvenkatakumarchakka gmail com> wrote:
> > > Hello,
> > >
> > > I am using simple program
> > >
> > > #include <gtk/gtk.h>
> > >
> > > int main(int argc, char *argv[])
> > > {
> > >     GtkWidget *window;
> > >     gtk_init(NULL, NULL);
> > >     window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
> > >     gtk_widget_show(window);
> > >     g_signal_connect(window, "destroy", G_CALLBACK(gtk_main_quit),
> > > NULL);
> > >     gtk_main();
> > >     return 0;
> > > }
> > >
> > > I compiled it using gcc simple.c `pkg-config --cflags gtk+-3.0 --libs`
> > > if I do ./a.out, GUI is showing up.
> > >
> > > but if I do "sudo ./a.out", I am seeing the following error :
> > >
> > > ================================================
> > > $ sudo ./a.out
> > > No protocol specified
> > > Unable to init server: Could not connect: Connection refused
> > >
> > > (a.out:7961): Gtk-WARNING **: cannot open display: :0
> > > ================================================
> > >
> > > As my application back end needs root privileges, I need to open the GUI
> > > using sudo only.
> > > Can some one help in fixing this issue ?
> > >
> > > The same code was working fine in Ubuntu 17.04. But I am facing this
> > > issue
> > > after upgrading to Ubuntu 17.10.
> >
> > Ubuntu 17.10 has switched to the Wayland display server, which is
> > designed to fix the security issues existent in X.
> >
> > Wayland only allows the user who started the X server to connect clients
> > to it.
> >
> > For more info, see https://bugzilla.redhat.com/1266771
> >
> > > Thanks
> > > --
> > > Lokesh Chakka,
> > > Mobile: 9731023458
> > > _______________________________________________
> > > gtk-app-devel-list mailing list
> > > gtk-app-devel-list gnome org
> > > https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list