How can I customize the graphical login prompt with a banner/message on a Mac OS X machine? (4260701)

VGP currently does not have a setting for customizing the login GUI of a Mac OS X system.  Console messages are though configurable using "Message of the Day".

Creating a group policy script will configure the login prompt.  To create a group policy that will change the login script, either create a new group policy or edit an already existing one.  In the Group Policy Object Editor for that particular policy, go to Computer Settings -> Unix Settings -> Scripts -> Refresh Scripts.  Click "Add".  Give it any Name (title doesn't matter), no parameters or options need to be used.  Click "Add".  Select the script entry and Click "Edit Script". Use the following format for the script, save the changes and click Apply/OK:

#!/bin/sh
touch /Library/Preferences/com.apple.loginwindow.plist
defaults write /Library/Preferences/com.apple.loginwindow "LoginwindowText" -string ' your_message '

Make sure that the single quote (') is only at the start and the end of your message, and nowhere in between.
VGP (vasgp) should be running on the Mac host; once VGP has applied the policy the next login prompt will contain the new message. This can also be forced on the client side by running "/opt/quest/bin/vgptool apply" and logging in again (a reboot of the Mac may be required).

An example script that was used successfully to display a customized graphical login on a Mac OS X is given below.

#!/bin/sh
touch /Library/Preferences/com.apple.loginwindow.plist
defaults write /Library/Preferences/com.apple.loginwindow "LoginwindowText" -string 'NOTICE TO USERS      This system is for authorized use only.'

For more details on writing Apple scripts please refer to the vendor.