MacOS上でFlutterアプリからシェルコマンドを実行するためのMethodChannelを実装する

AppDelegate.swift

import Cocoa
import FlutterMacOS

@NSApplicationMain
class AppDelegate: FlutterAppDelegate {
    override func applicationDidFinishLaunching(_ notification: Notification) {
        let controller : FlutterViewController = mainFlutterWindow?.contentViewController as! FlutterViewController
        let shellChannel = FlutterMethodChannel(name: "shell_executor",
                                                binaryMessenger: controller.engine.binaryMessenger)
        shellChannel.setMethodCallHandler({
          (call: FlutterMethodCall, result: @escaping FlutterResult) -> Void in
          if call.method == "executeCommand" {
              self.executeShellCommand(command: call.arguments as! String, result: result)
          } else {
              result(FlutterMethodNotImplemented)
          }
        })
        super.applicationDidFinishLaunching(notification)
    }

    private func executeShellCommand(command: String, result: FlutterResult) {
        let process = Process()
        process.launchPath = "/bin/bash"
        process.arguments = ["-c", command]
        let pipe = Pipe()
        process.standardOutput = pipe
        process.launch()
        process.waitUntilExit()

        let data = pipe.fileHandleForReading.readDataToEndOfFile()
        let output = String(data: data, encoding: .utf8)
        result(output)
    }
}