How do I use the vi text editor?
The vi text editor has three modes: command mode, input mode, and ex mode.
Command mode
When starting, vi begins in command mode. If you are ever unsure which mode you're in, press Esc to return to command mode. In command mode, you can move around with the arrow keys, or by using the vi movement keys, as follows:
h left j down k upl right
Several vi commands are listed in the table below:
CommandAction Ctrl-bGo back one page Ctrl-fGo forward one page xDelete the character the cursor is on Shift-xDelete the character before the cursor ddDelete the current line Shift-dDelete everything from the cursor to the end of the line uUndelete a line you just deleted Shift-uUndo all changes to the current line Shift-z-zSave your file and exit the vi editor
Note: In command mode, you can type a number before pressing a command key to repeat the command multiple times. For example, to delete eight lines from the cursor position, you could press 8 and then type dd .
Input mode
The input mode lets you insert or append text. To insert text before the cursor's current position, in command mode, press i . Similarly, to append after the cursor, you can type a . Remember that you can't move around with the cursor keys in this mode. When you're done entering text, press Esc to go back to command mode.
Ex mode
The ex mode is an extension of command mode. To get into it, press Esc and then : (the colon). The cursor will go to the bottom of the screen at a colon prompt. Write your file by entering :w and quit by entering :q . You can combine these to save and exit by entering :wq . However, if you're finished with your file, it's generally more convenient to type Shift-z-z from command mode.
For a more thorough list of vi command keys, see
A quick reference list of vi editor commands.
Hope this works.
Thanks
Hannan Saleemi.