Run NSTask in background for Swift

run_bg.swift

var taskQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0)
dispatch_async(taskQueue, { () -> Void in
    let task = NSTask()
    task.launchPath = "/bin/ls"
    task.arguments = []
    let pipe = NSPipe()
    task.standardOutput = pipe
    task.launch()
    let data = pipe.fileHandleForReading.readDataToEndOfFile()
    var dataString = NSString(data: data, encoding: NSUTF8StringEncoding)
    NSLog(dataString) // TODO: write your own code
})