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 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 ‘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)