Hi, I am not using any API's such as NSTask or anything from Swift-I made the app in Script Editor, using purely AppleScript. I preform the shell commands using AppleScript's "do shell script" command (see https://developer.apple.com/library/archive/technotes/tn2065/_index.html for how that command works). The problem with how I implement the progress bar is that there is no Stop button handler-that functionality is built-in to AppleScript. How do I make the program register the Stop button's click even while the script is on another task and the UI is unresponsive?

Hi, That would be a good solution, but I need the stderr of the command to handle it. My app is a network troubleshooting app, and it uses commands to attempt to access websites. If a (network) error is thrown by a command, my app needs that error immediately to handle it. If I use background commands, I will not be able to tell if a command failed or succeeded. I also can't access /dev/null, as my app is sandboxed. My app has it's own "trash bin" called "Tests.log" that is never referenced. Could I use that? (But the main question is about the stderr).

I've fixed it!

What's an ID? I'm new to UserDefaults.