root: ^2.0.4

import 'package:root/root.dart';

bool _status = false;

 Future<void> checkRoot() async {
    bool result = await Root.isRooted();
    setState(() {
      _status = result;
    });
  }
  
 later you can use _status in your code to let app know the root status. 
 

bool _status = false;

 Future<void> checkRoot() async {
    bool result = await Root.isRootAvailable();
    setState(() {
      _status = result;
    });
  }
  
 later you can use _status in your code to let app know the root status. 
 

String _result;

 Future<void> setCommand() async {
    String res = await Root.exec(cmd: "cat /proc/version");
    setState(() {
      _result = res;
    });
  }
  
  later you can use the _result in your code to let know the output of the given shell command.