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 ((oq#(cq) 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 (oqno-(cq.
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 (oqproduction(cq 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 provided.
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 management.
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 (oqconffiles(cq, including
xdm.options ).
use-sessreg
This option causes the
/etc/X11/xdm/Xsetup and
/etc/X11/xdm/Xreset scripts 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
(oqrun-xconsole(cq option has been removed.
Shell scripts named
/etc/X11/xdm/Xsetup and
/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.
