The graphical interface only provides display space. Running the X server by itself only leads to an empty screen, which is why most installations use a display manager to display a user authentication screen and start the graphical desktop once the user has authenticated. The three most popular display managers in current use are gdm3 (GNOME Display Manager), kdm (KDE Display Manager) and xdm (X Display Manager). Since the Falcot Corp administrators have opted to use the GNOME desktop environment, they logically picked gdm3
as a display manager too. The /etc/gdm3/daemon.conf
configuration file has many options (the list can be found in the /usr/share/gdm/gdm.schemas
schema file) to control its behaviour while /etc/gdm3/greeter.gsettings
contains settings for the greeter “session” (more than just a login window, it's a limited desktop with power management and accessibility related tools). Note that some of the most useful settings for end-users can be tweaked with GNOME's control center.
Since each graphical desktop provides its own window manager, choosing the former usually implies software selections from the latter. GNOME uses the mutter
window manager (or metacity
when run in GNOME Classic mode), KDE uses kwin
, and Xfce (which we present later) has xfwm
. The Unix philosophy always allows using one's window manager of choice, but following the recommendations allows an administrator to best take advantage of the integration efforts led by each project.
Older computers may, however, have a hard time running heavyweight graphical desktop environments. In these cases, a lighter configuration should be used. “Light” (or small footprint) window managers include WindowMaker (in the wmaker package), Afterstep, fvwm, icewm, blackbox, fluxbox, or openbox. In these cases, the system should be configured so that the appropriate window manager gets precedence; the standard way is to change the x-window-manager
alternative with the update-alternatives --config x-window-manager
command.
现代桌面环境和许多窗口管理器提供用户应用程序菜单列表。为了保持菜单与实际的应用程序更新一致,Debian 创建中心数据库注册所有安装的应用程序。新安装的软件包会在数据库中注册,并告知系统更新相应的菜单。该结果有 menu 软件包处理。
当软件包提供的应用程序需要在系统菜单中出现时,它会在
/usr/share/menu/
目录下生成一个文件。该文件描述应用程序的特性(包括是否属于图形应用程序),和它在菜单中的位置。软件包的安装后处理脚本运行
update-menus
命令,它会更新所有需要的文件。该命令不知道安装程序的所有菜单类型。因此,要显示菜单的软件包必须提供从菜单选项唤起的可执行脚本;脚本将把文件信息转化为应用程序可用的形式。这些脚本安装在
/etc/menu-methods/
目录。
The administrator can also have a say in the process and in the resulting generated menus. First, they can delete a menu element even when the matching application is installed, by simply storing in /etc/menu/
an empty file named according to the package providing the entries to be disabled. Second, the menu can be reorganized and sections renamed or grouped. The /etc/menu-methods/translate_menus
file is where this reorganization is defined and contains commented examples. Finally, new elements can be added to the menu, for example to start programs installed outside the packaging system, or to run a particular command such as starting a web browser on a particular page. These extra elements are specified in /etc/menu/local.element
files, which have the same format as other menu files available under /usr/share/menu/
.