Any operating system command line causes discussions over the Internet.
It may not look like it, but it will be a great ally.
A poorly executed change in your operating systems firewall can open doors/services to the world.
It does not matter if you use Unix, Linux, or Windows here.
Almost 99% of what is done on the command line reflects in graphical mode.
Also ReadTop 5 Best iPhone Apps For Developers and Programmers.
Learn more about the command line
The Code Academy offers a free Learn the Command Line course.
The course is in English, but I think I will have no significant difficulties with a little effort.
The course is focused on Unix operating systems, Linux, and macOS.
See how to move from the command line from one of these OSes!
