1. :e! drop all the changes of the current file.
2. vim - we use this pattern in bash to edit the output of another command. For instance:
3. C clear text after the cursor of the current line, which equals to the c+\$. Kindly notice the difference between c+c and C, the former is to clear the whole line and enter insert mode but the latter is to remove text after the cursor and switch to insert mode.