Google Chrome OS is an open source project and it is fast, simple, and more secure computer operating system based on Linux. Linux allows you to access the command line and Google chrome operating system also allows advanced users to access command line. if you want to open the command line in chrome OS please follow below steps to open command line in chrome operating system.
Step 1 : Click on CTRL+ALT+T on Keyboard
Step 2 : Now you will get crosh prompt. Type in shell and click Enter
Step 3: use sudo and the password chronos to get root access to Chrome OS.
You are done it. Now you can easily switch between command line interface and graphical interface by using ALT+TAB keyboard combination