Install ruby-open4 by entering the following commands in the terminal:
sudo apt update sudo apt install ruby-open4
Description:
library for managing child processes in Ruby
Open4 lets you open child process with handles on pid, stdin, stdout, and stderr: manage child processes and their I/O handles easily.
Homepage: https://github.com/ahoward/open4
Version: 1.3.4-1
Section: universe/ruby