How to change file by command?
- If you mean how to switch/open different files in library:
There is a small page/file shape image to the left top of the page. click it then a menu with all the files will appear in this case only one will show (main.cpp) but you can add more with + sign on the top of the menu.
- If you mean how to change/edit files do the above process and once you have finished designing/developing the file type ctrl+S to save.
Michal you have to be a little more descriptive about your problems.