--- name: "xdm.options" section: "5" platform: "linux" package: "xdm" version: "1:1.1.11-6.1" release: "Debian 13 (Trixie)" platforms: ["linux"] url: "https://new.carta.tech/xdm.options" --- # xdm.options(5) configuration options for the X display manager ## 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)](/xdm/1x.md). 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)](/nologin/5.md) file exists, its contents will be displayed using [**xmessage**(1x)](/xmessage/1x.md) (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)](/sessreg/1x.md) program to register X sessions managed by **xdm** in the [**utmp**(5)](/utmp/5.md) and [**wtmp**(5)](/wtmp/5.md) 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)](/xdm/1x.md) 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)](/sessreg/1x.md), [**xmessage**(1x)](/xmessage/1x.md), [**xdm**(1x)](/xdm/1x.md), [**nologin**(5)](/nologin/5.md), [**utmp**(5)](/utmp/5.md), [**wtmp**(5)](/wtmp/5.md)