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uxlaunch

NAME

uxlaunch - program to start the X desktop

SYNOPSIS

uxlaunch [OPTIONS] [-- SESSION]

DESCRIPTION

uxlaunch is a program that initiates the X server and desktop environment. It starts the main component of the desktop up as soon as the X server is ready and relies on autostart .desktop files for other applications to be started. uxlaunch Was designed to start the Moblin desktop but can launch Gnome, Xfce and other desktop sessions as well.

uxlaunch Works as a generic session launcher and prepares dbus, ssh-agent and ConsoleKit for the user session, launches the Xorg server, and then hands over session management to a session process (usually a main component such as mutter, the window mananger or something like xfce4-session. uxlaunch Also initializes the environment variables as close as it can to what a normal shell login would set.

After starting the session process, user startup applications are processed following the freedesktop.org Desktop File standard, starting up applications one by one.

Finally, uxlaunch cleans up the session if any of the session process, or X server process dies, and attempts to clean up all that was started properly. uxlaunch Does not restart itself for a new session, it relies on an external watchdog or baby sitter process to relaunch itself, such ash sysvinit or upstart.

OPTIONS

-u [USERNAME], --user=[USERNAME]

specify an alternative user to start the desktop session as. By default, uxlaunch will use the first user accound found through various tests, or the user "meego" if none valid is found.

-s [SESSION], --session=[SESSION]

specify an alternative session to start. This overrides the default session (Moblin) and attempts to start [SESSION] instead.

-t [TTY], --tty=[TTY]

Specify to use tty [TTY] instead of tty2 to run the X server on.

-v, --verbose

Display more information on stderr. All messages go to the logfile (/var/log/uxlaunch.log) in any case.

-h, --help

 Display terse usage information.
 show the help message.

 

INVOCATION

uxlaunch Is designed to be started from /etc/inittab. Normally, uxlaunch should be added as a runlevel 5 task, started as root, and restarted when needed. This can be achieved by adding the following line to /etc/inttab:

    x:5:respawn:/usr/sbin/uxlaunch

CONFIGURATION

uxlaunch configuration is done through /etc/sysconfig/uxlaunch. The file closely matches the command line options and allows you to specify most of the same parameters. The format of this file is simple "key=value" pairs:

user=[USERNAME]

session=[SESSION]

tty=[TTY]

See OPTIONS for a description of these settings.

dpi=[auto|DPI VALUE]

This option allows the user to override the default (120) dpi value used by uxlaunch. Either a numeric value (e.g. 96) or the special word "auto" can be used. If "auto" is specified, uxlaunch will defer the dpi setting to the XOrg server, which will attempt to autodetect your display size from the monitor and set an appropriate dpi value.

 

APPLICATION STARTUP

uxlaunch Supports desktop session startup by processing the files relevant to the freedesktop.org Desktop File Standard. uxlaunch Tries to honor the settings in XDG_CONFIG_HOME and XDG_CONFIG_DIRS and will retreive values from the users shell settings. After this and the session executable startup, uxlaunch will process autostart xdg files in the appropriate locations, prioritizing the users's override locations over default system wide startup file locations.

DESKTOP FILE EXTENSIONS

uxlaunch Supports a few extended key/value pairs in desktop autostart files to enhance the desktop startup process:

X-MeeGo-Priority=[Highest|High|Low|Late]

Prioritize startup of this application to be immediate (Highest), or in subsequent lower priority brackets (High, Low, Late). Each application in a bracket is only started after all the applications in the previous bracket are started, and a certain timeout has been waited. The time between applications becomes larger for lower priorities, and can be up to minutes for applications in the "late" bracket.

X-Meego-Watchdog=[Halt|Restart|Fail]

Attach a watchdog to the application. The watchdog can perform several actions based on the exit conditions of the application. Normally when an application exits, nothing happens. If "restart" is set, the application is restarted no matter what exit condition happened. If "fail" is set, the application is restarted if it returned an exit condition (non-0 exit code). If "halt" is set, the session is shut down if the application exits. This allows a critical application to generate a session restart or shutdown condition.

X-MeesGo-OnlyStartIfFileExists=[path]

X-MeesGo-DontStartIfFileExists=[path]

Make the startup of the application conditional on whether a file exists (OnlyStartIf...) or conditional on whether a file does not exist (DontStart...).

 

ENVIRONMENT

uxlaunch Copies the user's shell environment over to the session it starts by starting a subshell for the user and preserving the environment variables. Several variables influence how uxlaunch works:

XDG_CONFIG_HOME

XDG_CONFIG_DIRS

See the freedesktop.org standard for how these variables influence application startup.

X_DESKTOP_SESSION

Records the session name used in the current session. For use in programs that need to determine what session is running through this method.

LANG

SYSFONT

These two variables are set by reading /etc/sysconfig/i18n and parsing the content.

BUGS

Send bug reports to <meego-dev@meego.com>

SEE ALSO

The program is more fully described at http://meego.com/

AUTHOR

uxlaunch was written by Arjan van de Ven <arjan@linux.intel.com>, and Auke Kok <auke@linux.intel.com>.