NSTask and NSPipe example to comunicate with the command line objective-c

Question

Can someone show a quick example on how to use NSTask and NSPipe in conjunction to do this:

Charlie AI - run through terminal to comunicate with the AI

I want to create a nice GUI for it using xcode and objective c. I want to have 2 NSTextFields for the charlie's response and user input. Then have a send button to send the user input to the command line, then get the charlie's response and post it in the NSTextField.

I can handle the GUI stuff (NSTextField, ect.) But I need help with the objective-c coding part.

Thanks!

Elijah

Answer 1

Apple has some nice sample code that shows how to do most of that.

• https://developer.apple.com/library/archive/samplecode/Moriarity/Introduction/Intro.html

TaskWrapper.m contains all the clever stuff, but since you want to be able to send data to the task, you'll need to extend it a little, like so:

[task setStandardInput: [NSPipe pipe]];

To send input to the task, you can then do:

[[[task standardInput] fileHandleForWriting] writeData: ...];

To turn the NSTextField's value into data, you can do something like this:

NSData *data = [[inputTextField stringValue] 
                dataUsingEncoding:NSUTF8StringEncoding];

...and to set the current working directory for your sub-task, use [NSTask setCurrentDirectoryPath:]

e.g.

[task setCurrentDirectoryPath: @"/blah/blah"];
[task setLaunchPath: @"/blah/blah/server.sh"];

.... (other setup code)

[task launch];