The best way to do this is to have PolicyKit hadle the permissions issue (grub-reboot can only be run as root).
I filed a bug with grub to ship a PolicyKit action file to describe the action. https://savannah.gnu.org/bugs/index.php?34326 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-session in Ubuntu. https://bugs.launchpad.net/bugs/165065 Title: [wishlist] Ubuntu reboot into other OS Status in “gnome-session” package in Ubuntu: Triaged Bug description: Ubuntu (with Gnome) should can reboot directly into other Operating System listed in grub, as like as Kubuntu with KDE can do. See the screenshot to know what i am talking about. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-session/+bug/165065/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp