If you want to open some restricted graphical application with your username, you can get the following error:
vbox@core:~$ su - root -c gparted Password: (gpartedbin:27091): Gtk-WARNING **: cannot open display:
Well, there is a better and efficient way, via
gksu. They are doing practically the same thing, only the authentication is different. For
gksudo you need to be in sudoers list and you input your user's password and for
gksu you need the root password. Below you have an example with
vbox@core:~$ gksu gparted ====================== libparted : 1.8.8 ======================
That's pretty much it!