Android Question Execute the (getevent -l) command at the root

Hello.
Forgive my weakness in English.

How to use the getevent -l command in your program?

getevent is for listening to Android events.

My device is rooted.

I used this method, it does not answer, it has an error.
See the link : https://www.b4x.com/android/forum/threads/superuser-acquiring-root-permissions-the-easy-way.43322/

How can I listen to getevent -l events in the app and get output?

Thanks in advance for your answers.