xdm.options(5)							File Formats Manual						    xdm.options(5)

NAME

       xdm.options - configuration options for the X display manager

DESCRIPTION

       /etc/X11/xdm/xdm.options  contains  a  set  of  flags  that determine some of the behavior of the X display manager xdm(1x).  Most of xdm's
       behavior is customized through other files; consult the xdm manual page if this manual page does not describe  the  behavior  you  want	to
       alter.

       /etc/X11/xdm/xdm.options  may contain comments, which begin with a hash mark ('#') and end at the next newline, just like comments in shell
       scripts.  The rest of the file consists of options which are expressed as words separated by  hyphens,  with  only  one	option	per  line.
       Options are enabled by simply placing them in the file; they are disabled by prefixing the option name with 'no-'.

       Available options are:

       ignore-nologin
	      Normally,  if the nologin(5) file exists, its contents will be displayed using xmessage(1x) (if xmessage is available), and the user
	      will be returned to the xdm login screen after xmessage is dismissed instead of starting the X session.  If this option is  enabled,
	      xdm starts a session as usual (after xmessage is dismissed, if xmessage is available and the nologin file exists).  This behavior is
	      disabled by default: nologin is heeded, not ignored.

       restart-on-upgrade
	      Enable this option with caution on 'production' machines; it causes the daemon to be stopped and restarted on upgrade, even  if  the
	      process has children (which means it is managing X sessions).  Typically when a package that contains a daemon is being installed or
	      upgraded, its maintainer scripts stop a running daemon process before installing the new binary, and restart it after the new binary
	      is  installed.   Stopping xdm causes immediate termination of any sessions it manages; in some situations this could be an unwelcome
	      surprise (for instance, for remote xdm users who had no idea the administrator was performing system  maintenance).   On	the  other
	      hand,  for  machines that stay up for long periods of time, leaving the old daemon running can be a bad idea if the new version has,
	      for instance, a fix for a security vulnerability (overwriting xdm's executable on the file system has no effect on the copy  of  xdm
	      in memory).  The xdm package's pre-removal script checks to see if the xdm process has any children; if it does, it is possible that
	      someone's session would be killed by stopping xdm, so a warning is issued and an opportunity to abort the upgrade  of  xdm  is  pro-
	      vided.   Furthermore,  restarting xdm on upgrade can be surprising, because a locally-managed X server can change the active VT even
	      while other packages are continuing to upgrade.  If, by intent or accident, the X server does not honor the key sequence	to  switch
	      VTs back to a virtual console, this can be undesirable.  This behavior is disabled by default: xdm will be not be stopped or started
	      during an upgrade of its package; the administrator will have to do so by hand (with invoke-rc.d xdm restart  or	by  rebooting  the
	      system) before the newly installed xdm binary is used.

       start-on-install
	      Enable  this  option with caution; it causes the xdm daemon to be started immediately after the package is installed.  See the above
	      entry regarding restart-on-upgrade for other caveats regarding the consequences of starting the xdm daemon  during  package  manage-
	      ment.   This behavior is disabled by default: xdm will not be started when it is installed.  Changing this setting can affect future
	      installs if the package is removed, but not purged (which removes 'conffiles', including xdm.options).

       use-sessreg
	      This option causes the /etc/X11/xdm/Xreset script to call the sessreg(1x) program to register X  sessions  managed  by  xdm  in  the
	      utmp(5)  and  wtmp(5)  files.   If  it  is  disabled, the utmp and wtmp files will have no record of xdm sessions.  This behavior is
	      enabled by default; sessreg will be used.

       Users of older versions of the Debian system should note that  the  'run-xconsole'  option  has	been  removed.	 The  shell  script  named
       /etc/X11/xdm/Xreset can be edited to disable or modify the running of xconsole on the xdm greeter screen; see xdm(1x) for more information.

AUTHORS

       Stephen Early, Mark Eichin, and Branden Robinson customized xdm's startup and reset scripts and package maintainer scripts to implement the
       functionality described above.  This manual page was written by Branden Robinson.

SEE ALSO

       sessreg(1x), xmessage(1x), xdm(1x), nologin(5), utmp(5), wtmp(5)

Debian Project							    2004-10-31							    xdm.options(5)