The vi editor (short for
visual editor) is a screen editor which is available on almost all Unix
systems. Once you have learned vi, you will find that it is a fast and
powerful editor. vi has no menus but instead uses combinations of keystrokes
in order to accomplish commands. If you are just beginning to learn Unix, you
might find the Pico editor easier to use (most command options are displayed
at the bottom of the screen). If you use the Pine email application and have
composed or replied to a message you have probably already used Pico as it is
used for text entry. [For more information please refer to the PICO and PINE
To start using vi, at the
Unix prompt type vi followed by a
file name. If you wish to edit an existing file, type in its name; if you are
creating a new file, type in the name you wish to give to the new file.
Then hit Return.
You will see a screen similar to the one below which shows blank lines with
tildes and the name and status of the file.
vi's Modes and Moods
vi has two modes: the command
mode and the insert mode. It is essential that you know which mode you are in
at any given point in time. When you are in command mode, letters of the
keyboard will be interpreted as commands. When you are in insert mode the same
letters of the keyboard will type or edit text. vi always starts out in
command mode. When you wish to move between the two modes, keep these things
in mind. You can type i to enter
the insert mode. If you wish to leave insert mode and return to the command
mode, hit the ESC key. If you're
not sure where you are, hit ESC a
couple of times and that should put you back in command mode.
General Command Information
As mentioned previously, vi
uses letters as commands. It is important to note that in general vi commands:
are case sensitive - lowercase and
uppercase command letters do different things
are not displayed on the screen when
you type them
generally do not require a Return
after you type the command.
You will see some commands
which start with a colon (:).
These commands are ex commands
which are used by the ex editor. ex
is the true editor which lies underneath vi -- in other words, vi is the
interface for the ex editor.
To begin entering text in an
empty file, you must first change from the command mode to the insert mode. To
do this, type the letter i. When
you start typing, anything you type will be entered into the file. Type a few
short lines and hit Return at the
end of each of line. Unlike word processors, vi does not use word wrap. It
will break a line at the edge of the screen. If you make a mistake, you can
use the Backspace key to remove your errors. If the Backspace key doesn't work
properly on your system, try using the Ctrl h key combination.
You must be in command mode
if you wish to move the cursor to another position in your file. If you've
just finished typing text, you're still in insert mode and will need to press ESC
to return to the command mode.
Moving One Character at a Time
Try using your direction keys
to move up, down, left and right in your file. Sometimes, you may find that
the direction keys don't work. If that is the case, to move the cursor one
character at the time, you may use the h,
and l keys. These keys move you in
the following directions:
left one space l
right one space
down one space k
up one space
If you move the cursor as far
as you can in any direction, you may see a screen flash or hear a beep.
Moving among Words and Lines
While these four keys (or
your direction keys) can move you just about anywhere you want to go in your
file, there are some shortcut keys that you can use to move a little more
quickly through a document. To move more quickly among words, you might use
moves the cursor forward one word
moves the cursor backward one word (if in the middle of a
word, b will move you to the beginning of the current word).
moves to the end of a word.
To build on this further, you
can precede these commands with a number for greater movement. For example, 5w
would move you forward five words; 12b would move you backwards twelve words.
[You can also use numbers with the commands mentioned earlier. For example, 5j
would move you down 5 characters.]
Command Keys and Case
You will find when using vi
that lower case and upper case command keys are interpreted differently. For
example, when using the lower case w,
b, and e
commands, words will be defined by a space or a punctuation mark. On the other
hand, W, B,
and E commands may be used to move
between words also, but these commands ignore punctuation.
Two short cuts for moving
quickly on a line include the $
and the 0 (zero) keys. The $
key will move you to the end of a line, while the 0
will move you quickly to the beginning of a line.
To move the cursor to a line
within your current screen use the following keys:
moves the cursor to the top line of the screen.
moves the cursor to the middle line of the screen.
moves the cursor to the last line of the screen.
To scroll through the file
and see other screens use:
scrolls down one screen
scrolls up one screen
scrolls up a half a screen
scrolls down a half a screen
Two other useful commands for
moving quickly from one end to the other of a document are G
to move to the end of the file and 1G
to move to the beginning of the file. If you precede G
with a number, you can move to a specific line in the document (e.g. 15G would
move you to line 15).
Moving by Searching
One method for moving quickly
to a particular spot in your file is to search for specific text. When you are
in command mode, type a / followed
the text you wish to search for. When you press Return,
the cursor will move to the first incidence of that string of text. You can
repeat the search by typing n or
search in a backwards direction by using N.
To issue editing commands,
you must be in command mode. As mentioned before, commands will be interpreted
differently depending upon whether they are issued in lower or upper case.
Also, many of the editing commands can be preceded by a number to indicate a
repetition of the command.
Deleting (or Cutting) Characters,
Words, and Lines
To delete a character, first
place your cursor on that character. Then, you may use any of the following
deletes the character under the cursor.
deletes the character to the left of your cursor.
deletes from the character selected to the end of the word.
deletes all the current line.
deletes from the current
character to the end of the line.
Preceding the command with a
number will delete multiple characters. For example, 10x
will delete the character selected and the next 9 characters; 10X
will delete the 10 characters to the left of the currently selected character.
The command 5dw will delete 5
words, while 4dd deletes four
Pasting Text using Put
Often, when you delete or cut
text, you may wish to reinsert it in another location of the document. The Put
command will paste in the last portion of text that was deleted since deleted
text is stored in a buffer. To use this command, place the cursor where you
wish the deleted text to appear. Then use p
to reinsert the text. If you are inserting a line or paragraph use the lower
case p to insert on the line below
the cursor or upper case P to
place in on the line above the cursor.
Copying Text with Yank
If you wish to make a
duplicate copy of existing text, you may use the yank and put commands to
accomplish this function. Yank copies the selected text into a buffer and
holds it until another yank or deletion occurs. Yank is usually used in
combination with a word or line object such as the ones shown below:
copies a word into a buffer (7yw copies 7 words)
copies a line into a buffer (3yy will copy 3 lines)
Once the desired text is
yanked, place the cursor in the spot in which you wish to insert the text and
then use the put command (p for
line below or P for line above) to
insert the contents of the buffer.
Replacing or Changing Characters,
Words, and Lines
When you are using the
following commands to replace text, you will be put temporarily into insert
mode so that you can change a character, word, line, or paragraph of text.
replaces the current character with the next character you enter/type.
enter the character you are returned to command mode.
puts you in overtype mode until you hit ESC
which will then return
changes and replaces the current word with text that you type.
marks the end of the text you're changing.
Pressing ESC when you
will return you to command mode.
If you wish to insert new
text in a line, first position the cursor to the right of where you wish the
inserted text to appear. Type i to
get into insert mode and then type in the desired text (note that the text is
inserted before the cursor). Press ESC
to return to command mode.
Inserting a Blank Line
To insert a blank line below
the line your cursor is currently located on, use the o
key and then hit ESC to return to
the command mode . Use O to insert
a line above the line the cursor is located on.
You can use the append
command to add text at any place in your file. Append (a)
works very much like Insert (i)
except that it insert text after
the cursor rather than before it. Append is probably used most often for
adding text to the end of a line. Simply place your cursor where you wish to
append text and press a. Once
you've finished appending, press ESC
to go back to command mode.
Since vi does not use
automatic word wrap, it is not unusual in editing lines to end up with lines
that are too short and that might be improved if joined together. To do this,
place your cursor on the first line to be joined and type J.
As with other commands, you can precede J
with a number to join multiple lines (4J
joins 4 lines).
Be sure to remember this
command. When you make a mistake you can undo it. DO
NOT move the cursor from the line where you made the change. Then try
using one of the following two commands:
undoes the last change you made anywhere in the file.
Using u again
"undo the undo".
undoes all recent changes to the current line.
You cannot have moved
from the line to recover the original line.
Closing and Saving Files
When you edit a file in vi,
you are actually editing a copy of the file rather than the original. The
following sections describe methods you might use when closing a file,
quitting vi, or both.
Quitting and Saving a File
The command ZZ
(notice that it is in uppercase) will allow you to quit vi and save the edits
made to a file. You will then return to a Unix prompt. Note that you can also
use the following commands:
to save your file but not quit vi (this is good to do periodically in
case of machine crash!).
to quit if you haven't made any edits.
to quit and save edits (basically the same as ZZ).
Quitting without Saving Edits
Sometimes, when you create a
mess (when you first start using vi this is easy to do!) you may wish to erase
all edits made to the file and either start over or quit. To do this, you can
choose from the following two commands:
reads the original file back in so that you can start over.
wipes out all edits and allows you to exit from vi.
More about Combining Commands,
Objects, and Numbers
Now that you've learned some
basic vi commands you might wish to expand your skills by trying some fancy
combination steps. Some commands are generally used in combination with a text
object. We've already seen some examples of this. For example, when you use
the command dw to delete a word,
that combines the delete (d)
command with the word (w) text
object. When you wish to delete multiple words, you might add a number to this
combination. If you wished to delete 2 words you might use 2dw
or d2w. Either of these
combinations would work. So, as you can see, the general format for a command
(command) (text object) or
(command) (number) (text object)
You might wish to try out
some of the following combinations of commands and objects:
w (word to the left)
(word to the right or backward)
e (end of word)
(top of the screen)
(bottom of the screen)
(middle of the screen)
(zero - first character on a line)
(end of a line)
Repeating a Command
If you are doing repetitive
editing, you may wish to use the same command over and over. vi will allow you
to use the dot (.) to repeat the last basic command you issued. If for
example, you wished to deleted several lines, you could use dd
and then . (dot) in quick
succession to delete a few lines.
A Quick Word about Customizing Your
There are several options
that you can set from within vi that can affect how you use vi. For example,
one option allows you to set a right margin that will then force vi to
automatically wrap your lines as you type. To do this, you would use a
variation of the :set command. The
:set command can be used to change
various options in vi. In the example just described, you could, while still
in vi, type :set
wrapmargin=10 to specify that
you wish to have a right margin of 10. Another useful option is
:set number. This command
causes vi to display line numbers in the file you are working on.
view a listing of other options, you could type
To view only those options which are currently in effect, you can type
by itself. Options that you
set while in a vi session will apply during that session only. To make
permanent changes to your vi environment, you could edit your .exrc file.
However, you should not edit this file unless you know
what you are doing!
Useful vi Commands
one character (destructive backspace)
delete the current word (Note: ndw deletes n numbered words)
the current line (Note: ndd deletes n numbered lines)
delete all content to the right of the cursor
same as above
undo last command
paste line starting one line below/above current cursor
combine the contents of two lines
next n lines into named buffer [a-z]
place the contents of selected buffer below/above the current
Extensions to the Above Commands:
delete lines 3 through 18
move lines 16 through 25 to after line 30
copy specified lines and place after line 62
Cursor Relocation commands:
goto line [n]
g place cursor
on last line of text
move cursor left, right, down and up
move forward, backward in text, one page
move up, down one half page
move to end of line
move to beginning of line
Extensions to the Above:
backwards one word (Note: nb moves back n number of
move to end of current word
move to beginning of curent block
move to the end of current block
Searching and Substitution commands:
forward for string
backwards for string
repeat last search
repeat search in opposite direction
change the contents of the current word, (use ESC to stop
Replace all content to the right of cursor (exit replacement
mode with ESC)
Replace all content to the left of cursor (exit with ESC)
(Yow!) global replacement of string1 with string2
current character with next character type
Entering the Insert Mode:
Begin inserting text at current cursor location
Begin inserting text at the beginning of the current line
Begin appending text, one character to the right of current
Begin appending text at the end of the current line
Begin entering text one line below\above current line
Exit insertion mode and return to command mode
Exiting and Entering VI
save file and exit VI
same as above
return to last saved version of current file
quit without save, (Note :q! is required if changes have been
write without exit (:w! to force write)
write lines 1 through 10 to file newfile
>> file write
lines 340 through the end of the file and
to file newfile
temporarily to a shell
from shell to VI
execute UNIX command without leaving VI
read output of command into VI
read filename into VI
read in newfile and attach at the end of current
!sort file read
in contents of file after it has been passed
next file (works with wildcard filenames,
current line number
show line numbers
flag ("I") at bottom of screen when in insert
current values of VI variables
autoindent; after this enter the insert mode and
from this point on VI will indent each line to
location. Use ESC to stop the
set the autoindent tab one tab stop to the right
set the autoindent tab one stop to the left
default tab space to number n
contents of line one tab stop to the right
contents of line one tab stop to the left
Access this document at http://www.ccsf.org/Pub/Fac/vi.html
It was found at a website adopted by Sai Anand Balu of University of Carolina at Chapel Hill, Academic Technology and Networks.
More detailed help pages for vi editor can be found at http://www.ccsf.org/Pub/UNIXhelp/vi/ref.html