small swift 3 tool to convert an apple plist to json

plist-to-json.swift

//
//  main.swift
//  plist-to-json
//
//  Created by Dominik Pich on 20.07.17.
//  Copyright © 2017 Dominik Pich. All rights reserved.
//

import Foundation

//get arg
guard ProcessInfo.processInfo.arguments.count >= 2 else {
    print("usage: plist-to-json %input-plist--to-convert% [%optional-output-path%]")
    exit(-1)
}
let inputPath = (ProcessInfo.processInfo.arguments[1] as NSString).expandingTildeInPath
let inputURL = URL(fileURLWithPath: inputPath)

//read plist
var inputData: Data!
do {
    inputData = try Data(contentsOf:inputURL)
} catch {
    print("error reading data from file: \(error)")
    exit(-1)
}

var inputDict: [String:Any]!
do {
    inputDict = try PropertyListSerialization.propertyList(from: inputData, options: [], format: nil) as! [String:Any]
    // do something with the dictionary
} catch {
    print("error parsing data as plist: \(error)")
    exit(-1)
}

//write json
var jsonData : Data!
do {
    jsonData = try JSONSerialization.data(
        withJSONObject: inputDict,
        options: .prettyPrinted)
}
catch {
    print("error generating json data: \(error)")
    exit(-1)
}

//output (write or print)
if ProcessInfo.processInfo.arguments.count > 2 {
    let outputPath = (ProcessInfo.processInfo.arguments[2] as NSString).expandingTildeInPath
    let outputURL = URL(fileURLWithPath: outputPath)
    
    do {
        try jsonData.write(to: outputURL)
    }
    catch {
        print("error writing json data to disk: \(error)")
        exit(-1)
    }
}
else {
    guard let jsonString = String(data: jsonData, encoding: .utf8) else {
        print("error generating json output")
        exit(-1)
    }
    print(jsonString)
}