How to get the console logs and display in a textview [Swift]

Question

How can I get the console logs with all the print/Nslog contents and display it on a textview? Thank you very much for your answer.

"How can I get the console logs" You can't. If you could, there would be apps that display the console logs, and there are no such apps nowadays. — matt, Aug 10 '16 at 16:19

Mikeumus · Answer 1 · 2020-08-02T06:56:52.410

To accomplish this I modified the OutputListener Class described in this article titled "Intercepting stdout in Swift" by phatblat:

func captureStandardOutputAndRouteToTextView() {
    outputPipe = Pipe()

    // Intercept STDOUT with outputPipe
    dup2(self.outputPipe.fileHandleForWriting.fileDescriptor, FileHandle.standardOutput.fileDescriptor)
    
    outputPipe.fileHandleForReading.waitForDataInBackgroundAndNotify()
    
    NotificationCenter.default.addObserver(forName: NSNotification.Name.NSFileHandleDataAvailable, object: outputPipe.fileHandleForReading , queue: nil) {
      notification in
      
      let output = self.outputPipe.fileHandleForReading.availableData
      let outputString = String(data: output, encoding: String.Encoding.utf8) ?? ""
      
      DispatchQueue.main.async(execute: {
        let previousOutput = self.outputText.string
        let nextOutput = previousOutput + outputString
        self.outputText.string = nextOutput
        
        let range = NSRange(location:nextOutput.count,length:0)
        self.outputText.scrollRangeToVisible(range)
      })
      
      self.outputPipe.fileHandleForReading.waitForDataInBackgroundAndNotify()
    }
  }
}

score 2 · Answer 2 · edited May 23 '17 at 11:46

2

If you do not want to change existing code, you can;

1 - redirect the output of print to a known file. see instructions here; How to redirect the nslog output to file instead of console ( answer 4, redirecting)

2 - monitor the file for changes and read them in to display in your textView.

edited May 23 '17 at 11:46

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answered Aug 10 '16 at 16:16

john elemans

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HI I have manage to implement this code in swift but my other NSLogs or in swift is print is not registering to my text file – user3205472 Aug 12 '16 at 13:20

score 0 · Answer 3 · answered Aug 10 '16 at 15:55

You cannot do that.

You can use some logger, witch allow you to add custom log destination. You will have to change all print/NSLog calls to e.g. Log.verbose(message).

I'm using SwiftyBeaver. It allows you to define your custom destination. You can later read it and present in some text field.

score 0 · Answer 4 · edited May 23 '17 at 11:46

0

You can totally do that! Check this out: https://stackoverflow.com/a/13303081/1491675

Basically you create an output file and pipe the stderr output to that file. Then to display in your textView, just read the file and populate your textView.

edited May 23 '17 at 11:46

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answered Mar 18 '17 at 01:37

Chris

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How to get the console logs and display in a textview [Swift]

4 Answers4