Which file used by XDM specifies the default wallpaper?

Lena V.Jan 29, 2026

The answer is A, /etc/X11/xdm/Xsetup. This is a shell script that XDM executes as root right before the login screen appears, which makes it the correct place to set display-level things like the background wallpaper using xsetroot or a similar command. The exam loves to test this because the name "Xsetup" sounds generic, but its specific role in the pre-login display setup is exactly what makes it the wallpaper hook. The other options are either invented paths or config files that handle different concerns, so if you see a question about anything that needs to run visually before the login dialog shows up, Xsetup is your answer every time.

Toby R.Jan 11, 2026

The answer is A, /etc/X11/xdm/Xsetup. That file is a shell script that XDM runs as root before the login box appears, which is exactly where you drop your xsetroot or feh command to set the wallpaper.

Devraj B.Jan 20, 2026

Going with B on this one, and here is my reasoning. XDM reads its core runtime configuration from xdm.conf, and that file is where you set global display defaults, which absolutely covers visual presentation defaults like the wallpaper. The word "Defaults" in option C sounds tempting but that file handles resource settings for the chooser and greeter widgets, not the wallpaper path itself. Xsetup in option A is a shell script that runs before the login box appears, so it can call xsetroot or feh, but XDM does not read it to "specify" a wallpaper the way a config file does. The phrasing of the question, "specifies the default wallpaper," points me toward a declarative config file, and xdm.conf is the central config for XDM, so B is my pick.