Simple script for manipulating the screensaver setting on macOS

screensaver.swift

import Foundation

let arguments = CommandLine.arguments
switch arguments.count {
case 1:
	let moduleDict = CFPreferencesCopyAppValue("moduleDict" as CFString, "com.apple.screensaver" as CFString)
	print(moduleDict?["moduleName"] as! String)
	print(moduleDict?["path"] as! String)
case 3:
	let moduleDict = (CFPreferencesCopyAppValue("moduleDict" as CFString, "com.apple.screensaver" as CFString) as? NSDictionary)?.mutableCopy() as? NSMutableDictionary
	moduleDict?["moduleName"] = arguments[1]
	moduleDict?["path"] = arguments[2]
	CFPreferencesSetValue("moduleDict" as CFString, moduleDict, "com.apple.screensaver" as CFString, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost)
	CFPreferencesAppSynchronize("com.apple.screensaver" as CFString)
default:
	preconditionFailure("Invalid number of arguments")
}