setup-background-screensaver.bash

#!/bin/bash
# Set your desktop background to your screen saver.
# Install and activate with:
#   curl -fsSL https://git.io/vMgM9 | bash
#
# The screen saver is visible only on desktops created before the screen saver
# was started. If you create a desktop and wish to see the screen saver on it
# immediately, just do:
#   open -a ScreenSaverEngine
# to bring it in front of the default desktop background. You can also add
# /System/Library/Frameworks/ScreenSaver.framework/Resources/ScreenSaverEngine.app
# to the Dock and click it to bring it to the front of the desktop.
#
# ScreenSaverEngine uses minimal CPU when showing screen savers without
# animations and 0.0% CPU when the display is asleep. You can test this with:
#   while true; do sleep 0.5; echo "$(date) $(pgrep ScreenSaverEngine | xargs ps -o '%cpu=' -p)"; done
#
# ScreenSaverEngine exits with exit code 0 after the screen is unlocked. The
# KeepAlive key is set to restart it in this case or if it crashes.
#
# To disable the screen saver desktop until next login:
#   launchctl unload ~/Library/LaunchAgents/com.interestinglythere.backgroundsaver.plist
# To disable the screen saver desktop indefinitely:
#   launchctl unload -wF ~/Library/LaunchAgents/com.interestinglythere.backgroundsaver.plist
# To un-disable the screen saver desktop:
#   launchctl load -wF ~/Library/LaunchAgents/com.interestinglythere.backgroundsaver.plist
# To uninstall this:
#   rm ~/Library/LaunchAgents/com.interestinglythere.backgroundsaver.plist

set -e

# Unload any previous versions of this launch agent
launchctl stop com.interestinglythere.backgroundsaver || true
launchctl unload ~/Library/LaunchAgents/com.interestinglythere.backgroundsaver.plist || true

# Write launch agent to file
cat << EOF > ~/Library/LaunchAgents/com.interestinglythere.backgroundsaver.plist
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>KeepAlive</key>
	<true/>
	<key>Label</key>
	<string>com.interestinglythere.backgroundsaver</string>
	<key>ProcessType</key>
	<string>Background</string>
	<key>ProgramArguments</key>
	<array>
		<string>/System/Library/Frameworks/ScreenSaver.framework/Resources/ScreenSaverEngine.app/Contents/MacOS/ScreenSaverEngine</string>
		<string>-background</string>
	</array>
	<key>RunAtLoad</key>
	<true/>
	<key>ThrottleInterval</key>
	<integer>0</integer>
</dict>
</plist>
EOF

# Load and start launch agent
launchctl load ~/Library/LaunchAgents/com.interestinglythere.backgroundsaver.plist