How to redirect stdout to NSScrollView in Swift 4.0 Cocoa Application?

Question

I have a simple NSButton function executing a 'ls -la' command:

@IBAction func Convert(_ sender: NSButton) {
    let path = "/bin/ls"
    let arguments = ["-la"]
    sender.isEnabled = false
    let task = Process.launchedProcess(launchPath: path, arguments: arguments)
    task.waitUntilExit()
    sender.isEnabled = true
}

I need the stdout in my NSScrollView:

@IBOutlet weak var Output: NSScrollView!

Possible duplicate of [Real time NSTask output to NSTextView with Swift](https://stackoverflow.com/questions/29548811/real-time-nstask-output-to-nstextview-with-swift) — Martin R, Dec 12 '17 at 12:58
To set the _text_, you need a `@IBOutlet` of a `NSTextView` that's supposed to be inside the scroll view. If you just added a scroll view in your interface file, you should replace that with a NSTextView (which is automatically wrapped in a scroll view). You can then use `textView.string = "..."` to replace the text with the result of the output (see answer below). — ctietze, Dec 13 '17 at 09:13

score 1 · Accepted Answer · answered Dec 12 '17 at 10:28

1

You need a Pipe and a FileHandle

let path = "/bin/ls"
let arguments = ["-la"]
// sender.isEnabled = false
let task = Process()
task.launchPath = path
task.arguments = arguments
let outputPipe = Pipe()
task.standardOutput = outputPipe
task.launch()
task.waitUntilExit()
let data = (task.standardOutput as! Pipe).fileHandleForReading.readDataToEndOfFile()
let output = String(data:data, encoding: .utf8)!
print(output)
// sender.isEnabled = true

And please conform to the naming convention that variable and function / method names start with a lowercase letter.

answered Dec 12 '17 at 10:28

vadian

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Thanks a lot for your answer. Could you please explain how to link print(output) to my NSScrollView? – Eric Melda Dec 12 '17 at 10:39
A scroll view cannot display text directly. It's a container for another view. – vadian Dec 12 '17 at 10:43
If a scroll view is not able to display the output what else can I use to display the output in my app? – Eric Melda Dec 12 '17 at 10:53
An `NSTextView`. It's one of the views a scroll view can contain. – vadian Dec 12 '17 at 10:54
Output.documentView!.insertText(output) – Eric Melda Dec 12 '17 at 11:39

How to redirect stdout to NSScrollView in Swift 4.0 Cocoa Application?

1 Answers1