THE VI EDITOR

THE VI EDITOR

vi has 2 modes:command mode (initial or "default" mode) insert mode

[Esc] is used to switch to command mode. In general, vi commands:

are case-sensitive are not shown on the screen when you

type themdo not require an [Enter] after the

command.

OPEN A FILE vi is working on a copy of your file in the

buffer: your edits will not affect your original file until you save the buffer.

$ vi [filename] If the filename is omitted, vi will open an

unnamed buffer. A filename

must be unique inside its directory. can include any ASCII character except a

slash $ vi practice

$ vi letter

SAVING/LOADING FILE First check that you are in command mode

by pressing [ESC] To save file and quit the vi:

ZZ :wq

To safe file without quitting vi::w <filename> (write to specified file):w (write again):w! <filename> (to override existing file)

To load existing file::r <filename>

To edit new file::e <filename>

QUITTING VI

To return to the last saved version of the file::e! [Enter] :q! [Enter] (with quitting from vi)

vi normally won't let you throw away your edits. The exclamation point added to the :e or :q command causes vi to override this prohibition.

To quit vi if no changes were made:q

MOVING THE CURSOR

up k down j left h right l

<number><direction>: 4l moves the cursor four spaces to the

right, just as if you had typed l four times (llll)

A line is any text entered between newlines. beginning of the current line 0 end of the current line $ :set nu (to display line numbers)

MOVING THE CURSOR BY BLOCKS To the next word

w (symbols and punctuation as equivalent to words)W

To the previous wordb (symbols and punctuation as equivalent to words)B

Movement commands take numeric arguments 4w, or 5B

To the line number nn:nnnnGFor example, :4 or 4G (goes to the 4th line)

To the last line:$

INSERTING TEXT i inserts text before cursor. a appends text after cursor. A appends text to the end of current line. I inserts text at the beginning of line. With numeric prefixes, you might insert a row of underlines or

alternating characters: 50i*[ESC] inserts 50 asterisks

o opens blank line below cursor for text. O opens blank line above cursor for text. All of these commands leave you in insert mode. After inserting

text, press [ESC] to escape back to command mode. J joins two consecutive lines. Using a numeric argument with J joins that number of

consecutive lines: 3J.

CHANGING TEXT Command c replaces any text in your file specified by movement

command: cw to the end of the current word c2b back two words c$ to the end of line c0 to the beginning of line

c, like i and a, leaves you in insert mode until you press the [ESC]. General format of commands:

(command)(number)(movement command) (number)(command)(movement command)

Lines shortcuts cc changes an entire line. C is shortcut for c$.

r replaces a single character with another single character. No [ESC].

R overstrikes existing characters with new characters.

s (S) deletes character at cursor (line) and substitute text. ~ changes a case of letter. No number prefix or movement .

DELETING TEXT Command d deletes any text in your file. d is combined with a movement command to specify what to delete:

dw the current word d2b back two words d$ to the end of line d0 to the beginning of line

Lines shortcuts dd deletes an entire line (2dd) D is shortcut for d$.

x deletes a single character before the cursor. 5x deletes 5 characters before the cursor

:<range>d deletes lines in the range. Examples of the range are 1,$ 1,. .,$ 5,12 .,.+2

MOVING TEXT "cut and paste“ paradigm p puts the text in the buffer after the cursor

position. P puts the text before the cursor.

:nn , [Enter], p – to puts the text after nn position Once you delete text, you must restore it before

the next change command or delete command; otherwise, deleted text will be lost.

Transposing Two Letters : xp (delete character and put after cursor

command) transposes two letters. There is no command to transpose words.

COPYING TEXT

A yank command (y) copies the selected text into a buffer.

You can then place this copy elsewhere in the file with the p command.

y can be combined with any movement command (yw, y$, 4yy).

The shortcut yy, Y operates on an entire line.

:<range>y yanks lines in the range. Yanking uses the same buffer as deleting.

Each new deletion or yank replaces the previous contents of the yank buffer.

REPEATING OR UNDOING YOUR LAST COMMAND . (period) repeats last editing command.

Position the cursor where you want to repeat the editing command, and type a period.

Occasionally, vi has problems repeating a command.

u undoes your last command .The cursor need not be on the line where the original edit was made.

U undoes all edits on a single line, as long as the cursor remains on that line. Once you move off a line, you can no longer use U.

pu uu

SCROLLING

Ctrl+D down half screen Ctrl+U up half screen Ctrl+F forward one screen Ctrl+B back one screen Ctrl+L refresh screen (useful in telnet) z[Enter] moves current line to top of

thescreen and scroll. z understands a numeric prefix as a line

number that it will use in place of the current line.

SEARCHING

The search command is the special character / (slash):

/pattern[Enter] A pattern can be any sequence of characters. vi begins the search at the cursor and searches

forward, wrapping around to the start of the file if necessary.

To begin a search backward:

?pattern[Enter] n repeats search in the same direction. N Repeat search in opposite direction. / [Enter] repeats search forward. ? [Enter] repeats search backward.

SEARCHING/REPLACING :<range>s/string to change/desired string substitutes first occurence :<range>s/string to change/desired string/g substitutes all occurences in the range You can also use % instead of 1,$ to specify

every line in a file. If you'd like to confirm each replacement before it

is made, add the c option (for confirm) at the end of the substitute command:

:<range>s/string to change/desired string/gc

If you want to make the replacement, you must enter y (for yes) and press [Enter]; otherwise, simply press [Enter].