gistfile1.txt

## Block the user from being able to see our trickery
## Define the name and path to the LaunchAgent plist
PLIST="/Library/LaunchAgents/com.LockLoginScreen.plist"

## set the icon
swuIcon="<set to your ICON for use on lock screen if you want>"

## Define the text for the xml plist file
LAgentCore="<?xml version=\"1.0\" encoding=\"UTF-8\"?>
<!DOCTYPE plist PUBLIC \"-//Apple Computer//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\">
<plist version=\"1.0\">
<dict>
	<key>Label</key>
	<string>com.LockLoginScreen</string>
	<key>RunAtLoad</key>
	<true/>
	<key>LimitLoadToSessionType</key>
	<string>LoginWindow</string>
	<key>ProgramArguments</key>
	<array>
		<string>/System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/MacOS/LockScreen</string>
		<string>-session</string>
		<string>256</string>
	</array>
</dict>
</plist>"

## Create the LaunchAgent file
echo "Creating the LockLoginScreen LaunchAgent..."
echo "$LAgentCore" > "$PLIST"

## Set the owner, group and permissions on the LaunchAgent plist
echo "Setting proper ownership and permissions on the LaunchAgent..."
chown root:wheel "$PLIST"
chmod 644 "$PLIST"

## Use SIPS to copy and convert the SWU icon to use as the LockScreen icon

## First, back up the original Lock.jpg image
echo "Backing up Lock.jpg image..."
mv /System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Lock.jpg \
/System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Lock.jpg.bak

## Now, copy and convert the SWU icns file into a new Lock.jpg file
## Note: We are converting it to a png to preserve transparency, but saving it with the .jpg extension so LockScreen.app will recognize it.
## Also resize the image to 400 x 400 pixels so its not so honkin' huge!
##echo "Creating SoftwareUpdate icon as png and converting to Lock.jpg..."
##sips -s format png "$swuIcon" --out /System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Lock.jpg \
##--resampleWidth 400 --resampleHeight 400

cp $swuIcon /System/Library/CoreServices/RemoteManagement/AppleVNCServer.bundle/Contents/Support/LockScreen.app/Contents/Resources/Lock.jpg

## Now, kill/restart the loginwindow process to load the LaunchAgent
echo "Ready to lock screen. Restarting loginwindow process..."
kill -9 $(ps axc | awk '/loginwindow/{print $1}')