In order to use HPCC system robustly by command lines, please read the instruction to have a SSH client and X11 server installed in your computer.
For Windows machines
We recommend installing MobaXterm Home Edition (Installer edition). This program provides both an SSH client (command line) and an X-Windows (X11 server) system for running graphical user interface (GUI) programs on HPCC. (See MoabXTerm SSH Tutorial & )
For Mac OS machines
You can use Terminal program (installed with the operation system) on the task bar (or search for terminal) as your SSH Client. However, for running graphical user interface (GUI) programs on HPCC, you will need to install the X11-server program XQuartz. See https://www.xquartz.org/ for download instructions.