Shell keyboard shortcuts
On Linux shell, imagine you are executing a long command and then you remember that you need to execute other command first. Just found out an awesome feature where you can put a command in buffer (Ctrl+U), execute another command and then retrieve the buffer(Ctrl+Y). Awesome! Of course, Ctrl+A (Ctrl+A+A when you are in screen) to take you to the start of the line and Crtl+E to take you to end of the line.