Create a Login Message – Mac Kung Fu, 2nd Edition

Tip 345Create a Login Message

When Macs are used in public places, such as schools, it’s often necessary to ask users to agree to an acceptable use statement before they start using the computer. Adding one of these to a Mac is very easy to do, but that’s not all this trick can be used for. You could also add messages to remind yourself of something or even add a document that you can read at leisure without having to first log into your computer.

Adding a Logon Message

Here are the steps required to add a logon message:

  1. Create a document with TextEdit, which you’ll find in the Applications list in Finder, and save it as a rich-text or plain-text file. Note that only rich-text files will retain formatting, such as colors or bold text. Make sure you use systemwide fonts rather than any fonts installed specifically for your user account (this won’t be an issue if you’ve never manually installed fonts, but be careful not to use any Microsoft Office fonts like Candara or Cambria).

  2. Save the file to the desktop, giving it the name PolicyBanner.rtf or PolicyBanner.txt, depending on whether it’s rich-text format or plain text.

  3. Open a Terminal window (open Finder, select the Applications list, and then in the list of applications double-click Terminal within the Utilities folder), and then type the following, typing your password when prompted:

    sudo mkdir /Library/Security

    Close the Terminal window.

  4. Open a Finder window, and hit Shift+Command+G. In the dialog box that appears, type /Library/Security.

  5. Click and drag the PolicyBanner file you created to the Finder window. A dialog box will appear, asking you to authenticate, which you’ll need to do, so hit the relevant button and type your login password when prompted.

From now on, you’ll see the document appear in a window when you log in. Clicking the Accept button will clear it, after which you’ll see the standard login options.

If the Mac’s disk is encrypted with FileVault, the user will see the document when they boot, after they’ve typed their username but before the desktop appears. In fact, they won’t be blocked from using the computer until they click the Accept button.

Removing the Logon Message

To permanently eradicate this new addition to the login screen, again just browse to /Library/Security and move the PolicyBanner.rtf or PolicyBanner.txt file to the trash. You’ll be asked to authenticate again.