GDM Commands

GDM User Commands

The GDM package provides the following different commands in bindir intended to be used by the end-user:

gdmXnestchooser and gdmXnest Command Line Options

The gdmXnestchooser command automatically gets the correct display number, sets up access, and runs the nested X server command with the "-indirect localhost" argument. This provides an XDMCP chooser program. You can also supply as an argument the hostname whose chooser should be displayed, so gdmXnestchooser somehost will run the XDMCP chooser from host somehost inside a nested X server session. You can make this command do a direct query instead by passing the -d option as well. In addition to the following options, this command also supports standard GNOME options.

gdmXnestchooser Command Line Options

-x, --xnest=STRING

Nested X server command line, default is defined by the Xnest configuration option.

-o, --xnest-extra-options=OPTIONS

Extra options for nested X server, default is no options.

-n, --no-query

Just run nested X server, no query (no chooser)

-d, --direct

Do direct query instead of indirect (chooser)

-B, --broadcast

Run broadcast instead of indirect (chooser)

-b, --background

Run in background

--no-gdm-check

Don't check for running GDM

gdmflexichooser Command Line Options

The gdmflexiserver command provides three features. It can be used to run flexible (on demand) X displays, to run a flexible display via nested X server, and to send commands to the GDM daemon process.

Starting a flexible X display will normally lock the current session with a screensaver and will redisplay the GDM login screen so a second user can log in. This feature is only available on systems that support virtual terminals and have them enabled. This feature is useful if you are logged in as user A, and user B wants to log in quickly but user A does not wish to log out. The X server takes care of the virtual terminal switching so it works transparently. If there is more than one running display defined with flexible=true, then the user is shown a dialog that displays the currently running sessions. The user can then pick which session to continue and will normally have to enter the password to unlock the screen.

Nested displays works on systems that do not support virtual terminals. This option starts a flexible display in a window in the current session. This does not lock the current session, so is not as secure as a flexible server started via virtual terminals.

The gdmflexiserver --command option provides a way to send commands to the GDM daemon and can be used to debug problems or to change the GDM configuration.

In addition to the following options, gdmflexiserver also supports standard GNOME options.

gdmflexichooser Command Line Options

-c, --command=COMMAND

Send the specified protocol command to GDM

-n, --xnest

Start a flexible X display in Nested mode

-l, --no-lock

Do not lock current screen

-d, --debug

Turns on debugging output which gets sent to syslog. Same as turning on debug in the configuration file.

-a, --authenticate

Authenticate before running --command

-s, --startnew

Starts a new flexible display without displaying a dialog asking the user if they wish to continue any existing sessions.

gdmdynamic Command Line Options

gdmdynamic allows the management of displays in a dynamic fashion. It is typically used in environments where it is not possible to list the possible displays in the GDM configuration files. The gdmdynamic command can be used to create a new display on a particular display number, run all newly created displays, or remove a display. The gdmdynamic command can also be used to list all attached displays or only those attached displays that match a pattern. The -a option is used to add a display, the -r option is used to run (or release) a display, the -d option is used to delete a display, and the -l option lists existing displays. Only one of these four options can be specified at a time, so in the life cycle of a particular display, the command will be run once to add, again to release (run) the display, and finally to delete when the session is to be terminated.

This program is designed to manage multiple simultaneous requests and tries to avoid flooding the daemon with requests. If the sockets connection is busy, it will sleep and retry a certain number of times that can be tuned with the -s and -t options.

gdmdynamic Command Line Options

-a display=server

Add a new display configuration, leaving it in the DISPLAY_CONFIG state. For example, "-a 2=StandardServerTwo" "-a 3=/usr/X11R6/bin/X -dev /dev/fb2"

The display will not actually be started until the display is released by calling gdmdynamic again with the -r option.

-r

Release (run) all displays waiting in the DISPLAY_CONFIG state.

-d display

Delete a display, killing the X server and purging the display configuration. For example, "-d 3".

-l [pattern]

List displays via the ATTACHED_SERVERS gdmflexiserver command. Without a pattern lists all attached displays. With a pattern will match using glob characters '*', '?', and '[]'. For example: "-l Standard*" "-l *Xorg*"

-v

Verbose mode. Prints diagnostic messages. to GDM.

-b

Background mode. Fork child to do the work and return immediately.

-t RETRY

If the daemon socket is busy, gdmdynamic will retry to open the connection the specified RETRY number of times. Default value is 15.

-s SLEEP

If the daemon socket is busy, gdmdynamic will sleep an amount of time between retries. A random number of seconds 0-5 is added to the SLEEP value to help ensure that multiple calls to gdmdynamic do not all try to restart at the same time. A SLEEP value of zero causes the sleep time to be 1 second. Default value is 8 seconds.

gdmphotosetup Command Line Options

Allows the user to select an image that will be used as the user's photo by GDM's face browser, if enabled by GDM. The selected file is stored as ~/.face. This command accepts standard GNOME options.

gdmthemetester Command Line Options

gdmthemetester takes two parameters. The first parameter specifies the environment and the second parameter specifies the path name or the name of a theme to view. This is a tool for viewing a theme outside of GDM. It is useful for testing or viewing themes. gdmthemetester requires that the system support gdmXnest. Note that themes can display differently depending on the theme's "Show mode". gdmthemetester allows viewing the themes in different modes via the environment option. Valid environment values and their meanings follow:

console       - In console mode.
console-timed - In console non-flexi mode.
flexi         - In flexi mode.
xdmcp         - In remote (XDMCP) mode.
remote-flexi  - In remote (XDMCP) & flexi mode.

GDM Root User Commands

The GDM package provides the following different commands in sbindir intended to be used by the root user:

gdm and gdm-binary Command Line Options

The gdm command is really just a script which runs the gdm-binary, passing along any options. Before launching gdm-binary, the gdm wrapper script will source the <etc>/profile file to set the standard system environment variables. In order to better support internationalization, it will also set the LC_MESSAGES environment variable to LANG if neither LC_MESSAGES or LC_ALL are set. If you really need to set some additional environment before launching GDM, you can do so in this script.

gdm and gdm-binary Command Line Options

--help

Gives a brief overview of the command line options.

--nodaemon

If this option is specified, then GDM does not fork into the background when run. You can also use a single-dash version, "-nodaemon" for compatibility with other display managers.

--no-console

Tell the daemon that it should not run anything on the console. This means that none of the attached servers from the [servers] section will be started, and the console will not be used for communicating errors to the user. An empty [servers] section automatically implies this option.

--config=CONFIGFILE

Specify an alternative configuration file.

--preserve-ld-vars

When clearing the environment internally, preserve all variables starting with LD_. This is mostly for debugging purposes.

--version

Print the version of the GDM daemon.

--wait-for-go

If started with this option, gdm will init, but only start the first attached display and then wait for a GO message in the fifo protocol. No greeter will be shown until the GO message is sent. Also flexiserver requests will be denied and XDMCP will not be started until GO is given. This is useful for initialization scripts which wish to start X early, but where you don't yet want the user to start logging in. So the script would send the GO to the fifo once it is ready and GDM will then continue. This functionality was added in version 2.5.90.0.

gdmsetup Command Line Options

gdmsetup runs a graphical application for modifying the GDM configuration file. Normally on systems that support the PAM userhelper, this is setup such that when you run gdmsetup as an ordinary user, it will first ask you for your root password before starting. Otherwise, this application may only be run as root. This application supports standard GNOME options.

gdm-restart Command Line Options

gdm-restart stops and restarts GDM by sending the GDM daemon a HUP signal. This command will immediately terminate all sessions and log out users currently logged in with GDM.

gdm-safe-restart Command Line Options

gdm-safe-restart stops and restarts GDM by sending the GDM daemon a USR1 signal. GDM will be restarted as soon as all users log out.

gdm-stop Command Line Options

gdm-stop stops GDM by sending the GDM daemon a TERM signal.

GDM Internal Commands

The GDM package provides the following different commands in libexecdir intended to be used by the gdm daemon process.

gdmchooser and gdmlogin Command Line Options

The gdmgreeter and gdmlogin are two different login applications, either can be used by GDM. gdmgreeter is themeable with GDM themes while gdmlogin is themable with GTK+ themes. These applications are normally executed by the GDM daemon. Both commands support standard GNOME options.

gdmchooser Command Line Options

The gdmchooser is the XDMCP chooser application. The gdmchooser is normally executed by the GDM daemon. It supports the following options for XDM compatibility. This command supports standard GNOME options.

gdmchooser Command Line Options

--xdmaddress=SOCKET

Socket for XDM communication.

--clientaddress=ADDRESS

Client address to return in response to XDM. This option is for running gdmchooser with XDM, and is not used within GDM.

--connectionType=TYPE

Connection type to return in response to XDM. This option is for running gdmchooser with XDM, and is not used within GDM.

gdm-ssh-session

The gdm-ssh-session is normally executed by the GDM daemon when starting a secure remote connection through ssh. It does not take any options.