https://www.control-escape.com/linux/editing-vim.html
The thing you have to understand about vi and its work-alike editors is modality. Most programs have just one mode, accepting input and placing it at the cursor. This is what you probably expect from a program. But vi has other modes. When you start vi, you’ll be in “Normal” mode, which is really command mode. When you are in Normal mode, whatever you type is considered not to be input, but commands that vi will try to execute.
This may sound a little crazy, but it is actually a very powerful way to edit documents. Even if you hate it, the ubiquity of vi means that you’re going to need to learn the basics, because sometimes you just have to use it. On the other hand, if you enjoy working at a command line, then you may end uploving vi.
Lesson 1: How to Quit vi
Since vi is the default editor, there’s a good chance you got dropped into it without knowing it. This can be extremely frustrating if you don’t know your way around the program.
To exit vi without saving changes, hit Escape a couple of times to ensure you are in Normal mode, and then type:
Lesson 2: Editing with vi
Start vi and press i. The cursor may change shape, and INSERT is displayed at the bottom of the screen (in most vi clones). You are now in insert mode — all your keystrokes are entered into the current buffer and are displayed to the screen.
Hit the Escape key. The cursor changes shape again, and INSERT has disappeared. You are back in Normal mode. Hitting Escape a few times will pretty much always cancel whatever you are doing and return you to Normal mode.
Command mode is also where you move around in the file. On most systems, you can use the arrow keys to move the cursor. If that fails, cursor movement can be accomplished with the hjkl keys:
h move left one character
j move down one character
k move up one character
l move right one character
vi has its own command line, which you access by typing a colon. Commands typed at the command line will not be executed until you hit Enter, just like in the shell.
Many of the commands that you will use in command mode begin with a colon. For example, the command to quit is :q, as we learned in Lesson 1 above. Actually, in Lesson 1 we added !, which tells vi to “force” the operation. If you have edited the file, typing :q will not immediately exit the program, but instead produce this error message:
E37: No write since last change (add ! to override)
To save your changes, use the :w command (“Write”). You can save and quit all in one go by typing both commands together:
Of course, if you started vi without giving a file name, you’ll need to provide one. For example, to save your working file as test.txt, you would type:
Try editing some text now.
- Start vi
- Hit i to go to Insert mode.
- Type some text.
- Hit Escape to return to Normal mode.
- Type :w test.txt to save your work
- Type :q to quit
vi Quick Reference
Movement
- h, j, k, l
- left, down, up, right
- $
- To the end of the line
- ^
- To the beginning of the line
- G
- To the end of the file
- :1
- To the beginning of the file
- :47
- To line 47
Editing
- dd
- Remove a line
- 5dd
- Removing five lines
- r
- Replace a character
- x
- Delete a character
- 5x
- Delete 5 characters
- u
- Undo last action
- J
- Join current and next lines (Note the capital — hold the Shift key)
Saving and Quitting
- :q
- Quit
- :q!
- Quit without saving
- :wq
- Write and quit
- :w
- Write (without quitting)
- :e!
- Reload currently open file from disk
- :w test.txt
- Write buffer to file
test.txt
- :e test2.txt
- Open file
test2.txt
1GB RAM
30GB SSD
2GB Swap