gnome-session-save --logout

另外,看一下–help输出,也许你想使用–force-logout选项.

Usage:
  gnome-session-save [OPTION...]

Help Options:
  -h,--help               Show help options
  --help-all               Show all help options
  --help-gtk               Show GTK+ Options

Application Options:
  --logout                 Log out
  --force-logout           Log out,ignoring any existing inhibitors
  --logout-dialog          Show logout dialog
  --shutdown-dialog        Show shutdown dialog
  --gui                    Use dialog Boxes for errors
  --display=DISPLAY        X display to use