How to Use vi
From wikipedia: vi is a screen-oriented text editor written by Bill Joy in 1976 for an early BSD release. The name vi is derived from the shortest unambiguous abbreviation for the command visual in ex; the command in question switches the line editor ex to visual mode. Current releases of vi are free and open source software, usually released under permissive free software licenses> such as the BSD License. vi is the commandline text editor of choice (well, not if you ask the emacs crowd), but the reason for it’s widespread use is that it can fit on a floppy disk to aid system recovery. It is a power editor with many options to navigate and manipulate text and we’ll covers the basics here.
Download the Cheat Sheet: vicheatsheet.pdf (source )
Starting vi:
You may use vi to open an already existing file by typing
vi filename
where “filename” is the name of the existing file. If the file is not in your current directory, you must locate it and type the full path to that file.
Or you may create a new file by typing
vi newfilename
where “newfilename” is the name you wish to give the new file.
To open a new file called “newfilename” enter
vi newfilename
On the screen, you will see blank lines, each with a tilde (~) at the left, and a line at the bottom giving the name and status of the new file:
~
"newfilename" [New file]
vi Modes
vi has two modes:
- command mode
- insert mode
In command mode, the letters of the keyboard perform editing functions (like moving the cursor, deleting text, etc.). To enter command mode, press the escape <Esc> key.
In insert mode, the letters you type form words and sentences. Unlike many word processors, vi starts up in command mode. To enter or edit text you must be in insert-mode, and by pressing the <i> key, vi will enter into that mode.
After typing ‘i’ it may look like nothing changes, but you are in inset mode. In general, vi’s commands do not display on the screen and do not require the Return key to be pressed. Type a few short lines and press <Enter> at the end of each line. If you type a long line, you’ll notice the vi application does not use a word wrap function, it simply breaks the line at the edge of the screen. If you make a mistake, pressing <Backspace> or <Delete> may remove the error, depending on your terminal type.
Moving the Cursor
To move the cursor to another position, you have to be in the command mode. Let’s say you are finished typing text but you are still in insert mode. Go back to command mode by pressing <Esc>. If you are not sure which mode you are in, press <Esc> once or twice until you hear a beep. When you hear the beep, you are in command mode.
The cursor is controlled with four keys: h, j, k, l.
Key Cursor Movement
--- ---------------
h left one space
j down one line
k up one line
l right one space
When you have gone as far as possible in one direction, the cursor stops moving and you hear a beep. For example, you can’t use l to move right and wrap around to the next line, you must use j to move down a line. We’ll cover how to move more quickly in just a moment.
Basic Editing
To edit commands you must be in command mode. Many of the editing commands have a different function depending on whether they are typed as upper or lowercase. Often, editing commands can be preceded by a number to indicate a repetition of the command.
Deleting Characters
To delete a character from a file, move the cursor until it is on the incorrect letter, then type
x
The character under the cursor disappears. To remove five characters (the one under the cursor and the next four) type
5x
To delete the character before the cursor, press
X (uppercase)
Deleting Words
To delete a word you need to place the cursor to the first letter of the word, and type
dw
This command deletes the word and the space following it.
To delete four words type
4dw
Deleting Lines
To delete a whole line on text you need to type
dd
The cursor does not have to be at the beginning of the line. Typing dd deletes the entire line containing the cursor and places the cursor at the start of the next line. To delete three lines, type
3dd
To delete from the cursor position to the end of the line, type
D (uppercase)
Replacing Characters
To replace one character with another character:
- Move the cursor to the character to be replaced.
- Type r
- Type the character you want to replace it with.
The new character will appear, and you will still be in command mode.
Replacing Words
To replace one word with another word, move to the start of the incorrect word and type
cw
The last letter of the word to be replaced will turn into a $. You are now in insert mode and may type the replacement. The new text does not need to be the same length as the original. Press <Esc> to get back to command mode. To replace four words, type
4cw
Replacing Lines
To change text from the cursor position to the end of the line:
- Type C (uppercase).
- Type the replacement text.
- Press <Esc>.
Inserting Text
To insert text in a line:
- Position the cursor where the new text should go.
- Type i
- Enter the new text.
The text is inserted BEFORE the cursor.
4. Press <Esc> to get back to command mode.
Appending Text
To add text to the end of a line:
- Position the cursor on the last letter of the line.
- Type a
- Enter the new text.
This adds text AFTER the cursor.
4. Press <Esc> to get back to command mode.
Joining LinesTo join two lines together:
- Put the cursor on the first line to be joined.
- Type J
To join three lines together:
- Put the cursor on the first line to be joined.
- Type 3J
UndoingTo undo your most recent edit, type
u
To undo all the edits on a single line, type
U (uppercase)
Undoing all edits on a single line only works as long as the cursor stays on that line. Once you move the cursor off a line, you cannot use U to restore the line.
Moving Around in a File
There are shortcuts to move more quickly though a file. All these work in command mode.
Key Movement
--- --------
w forward word by word
b backward word by word
$ to end of line
0 (zero) to beginning of line
H to top line of screen
M to middle line of screen
L to last line of screen
G to last line of file
1G to first line of file
<Control>f scroll forward one screen
<Control>b scroll backward one screen
<Control>d scroll down one-half screen
<Control>u scroll up one-half screen
Moving by SearchingTo move quickly by searching for text, while in command mode:
- Type / (slash).
- Enter the text to search for.
- Press <Return>.
The cursor moves to the first occurrence of that text.
To repeat the search in a forward direction, type
n
To repeat the search in a backward direction, type
N
Closing and Saving a FileWith vi, you edit a copy of the file, rather than the original file. Changes are made to the original only when you save your edits.
To save the file and quit vi, type
ZZ
The vi editor editor is built on an earler Unix text editor called ex. ex commands can be used within vi. ex commands begin with a : (colon) and end with a <Return>. The command is displayed on the status line as you type. Some ex commands are useful when saving and closing files.
To save the edits you have made, but leave vi running and your file open:
- Press <Esc>.
- Type :w
- Press <Return>.
To quit vi, and discard any changes your have made since last saving:
- Press <Esc>.
- Type :q!
- Press <Return>.
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Tags: text editor, vi, vim
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