get json from preferences

prefs_to_json.swift

//
//  main.swift
//  prefs
//
//  Created by Francois Levaux on 21.03.17.
//  Copyright © 2017 Francois Levaux. All rights reserved.
//
// Similar to $ plutil -convert json /Library/Preferences/io.fti.SplashBuddy.plist -o - -r

import Foundation

let app = "io.fti.SplashBuddy"

func preferencesToDict(array: CFArray) -> [Dictionary<String, Any>] {
    return lookupPreferencesValues(array: (array as! Array<String>))
}

func lookupPreferencesValues(array: Array<String>) -> [Dictionary<String, Any>] {
    return array.map({[$0: CFPreferencesCopyAppValue($0 as CFString, app as CFString) as Any]})
}

guard let prefs = CFPreferencesCopyKeyList(app as CFString,
                                           kCFPreferencesAnyUser,
                                           kCFPreferencesAnyHost).map(preferencesToDict) else {
    print("nil")
    exit(1)
}

do {
    guard JSONSerialization.isValidJSONObject(prefs) else {
        print("Invalid object")
        exit(1)
    }
    
    let json = try JSONSerialization.data(withJSONObject: prefs as Any, options: [.prettyPrinted])
    
    if let jsonString = String(data: json, encoding: .utf8) {
        print(jsonString)
    }
    
} catch {
    dump(error)
}