[Gambas-user] Stopping a CLI program

[John Rose]

I want  to be able to stop a CLI program (started by an Exec statement) 
as though the user was keying in a special character from the keyboard. 
Specifically, I want to stop ffmpeg recording to disk when grabbing 
streaming video using x11grab. The recording is stopped by the user 
entering q if the program is started by entering ffmpeg (followed by its 
parameters) in a Terminal. How is this done in Gambas3?