Timing the time spend on executing through NSTask

TimingCommandExecution.swift

//#!/usr/bin/swift
import Foundation
import QuartzCore

//let task = Process()
//task.launchPath = "/usr/bin/defaults"
//task.arguments = ["write","com.apple.dock","persistent-apps","-array-add","{\"tile-type\"=\"spacer-tile\";}"]
//let pipe = Pipe()
//task.standardOutput = pipe
//task.standardError = pipe
//task.launch()
//task.waitUntilExit()

//let task2 = Process()
//task2.launchPath = "/usr/bin/killall"
//task2.arguments = ["Dock"]
//let pipe2 = Pipe()
//task2.standardOutput = pipe2
//task2.standardError = pipe2
//task2.launch()
//task2.waitUntilExit()

func executionTimeInterval( block: () -> () ) -> CFTimeInterval {
    let start = CACurrentMediaTime()
    block();
    let end = CACurrentMediaTime()
    return end - start
}

let test = executionTimeInterval {
    let task = Process()
//    task.launchPath = "/usr/sbin/lsof"
    task.launchPath = "/bin/ls"
    task.arguments = ["-lAh"]
    let pipe = Pipe()
    task.standardOutput = pipe
    task.standardError = pipe
    task.launch()
    task.waitUntilExit()
    
    let data = pipe.fileHandleForReading.readDataToEndOfFile()
    let output: String = NSString( data: data, encoding: String.Encoding.utf8.rawValue )! as String
    print( output )
}

print( test )