mac geekery

It used to be that if you changed the file at /Library/Desktop Pictures/Aqua Blue.jpg then loginwindow would display that picture as the background instead. In fact, while it’s still the case, you can also set a key to explicitly define which file should be used as the desktop picture. My personal preference is to alter a setting over moving around system files (no matter how inert).

In this example, I’m going to change the background to use the Nature/Stones.jpg file instead of Aqua Blue.jpg.

$ sudo defaults write /Library/Preferences/com.apple.loginwindow DesktopPicture -string "/Library/Desktop Pictures/Nature/Stones.jpg"

Now you can logout to get the login window to show up and your change should be noted. If not, either reboot or kill loginwindow.

If you’d rather not use the Terminal for this (blasphemy) you can use a gooey tool called Login Window Manager that lets you do this and some other fun things with loginwindow.