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vi Editor and Commands

The default editor that comes with the UNIX operating system is called vi (visual editor). The vi editor is a full screen editor and has two modes of operation:

1. Command mode: commands which cause action to be taken on the file
2. Insert mode: in which entered text is inserted into the file

In command mode, every character typed is a command that does something to the text file being edited. In insert mode, every character typed is added to the text in the file; pressing the <Esc> (Escape) key turns off the Insert mode.

Start vi

vi your-filename    edit your-filename starting at line 1
vi -r your-filename     recover your-filename that was being edited when system crashed

Exit vi

The cursor moves to bottom of screen when a colon (:) is typed. The command is completed by hitting the <Enter> key.

:x<Enter>     quit vi, writing out modified file to file named in original invocation
:wq<Enter>     quit vi, writing out modified file to file named in original invocation
:q<Enter>     quit (or exit) vi
:q!<Enter>     quit vi even though latest changes have not been saved

Moving the Cursor

The mouse does not move the cursor within the vi editor. You must use the key commands listed below. On some UNIX platforms, the arrow keys may be used as well; however, since vi was designed with the Qwerty keyboard (containing no arrow keys) in mind, the arrow keys sometimes produce strange effects in vi and should be avoided.

Note: The symbol ^ before a letter means that the <Ctrl> key should be held down while the letter key is pressed.

j or <Enter> [or down-arrow]     move cursor down one line
k [or up-arrow] move cursor up one line
h or <Backspace> [or left-arrow]     move cursor left one character
l or <Space> [or right-arrow]     move cursor right one character
0 (zero)     move cursor to start of current line
$     move cursor to end of current line
w     move cursor to beginning of next word
b     move cursor back to beginning of preceding word
:0<Enter> or 1G     move cursor to first line in file
:n<Enter> or nG     move cursor to line n
:$<Enter> or G     move cursor to last line in file

Screen Manipulation

The following commands allow the vi editor screen to move up or down several lines and to be refreshed.

^f     move forward one screen
^b     move backward one screen
^d     move down (forward) one half screen
^u     move up (back) one half screen
^l     redraws the screen
^r     redraws the screen, removing deleted lines

Inserting or Adding Text

The following commands allow you to insert and add text. Each of these commands puts the vi editor into insert mode; thus, the <Esc> key must be pressed to terminate the entry of text and to put the vi editor back into command mode.

i     insert text before cursor, until <Esc> hit
I     insert text at beginning of current line, until <Esc> hit
a     append text after cursor, until <Esc> hit
A     append text to end of current line, until <Esc> hit
o     open and put text in a new line below current line, until <Esc> hit
O     open and put text in a new line above current line, until <Esc> hit

Undo and Redo

You cannot replace or delete text by highlighting it with the mouse.

u     UNDO WHATEVER YOU JUST DID
This command acts like a toggle, undoing and redoing most recent action. So cannot go back more than one step.

Changing Text

The following commands allow you to modify text.

r     replace single character under cursor (no <Esc> needed)
R     replace characters, starting with current cursor position, until <Esc> hit
cw     change the current word with new text, starting with the character under cursor, until <Esc> hit
cNw     change N words beginning with character under cursor, until <Esc> hit;
e.g., c5w changes 5 words
C     change (replace) the characters in the current line, until <Esc> hit
cc     change (replace) the entire current line, stopping when <Esc> is hit
Ncc or cNc     change (replace) the next N lines, starting with the current line, stopping when <Esc> is hit

Deleting Text

x     delete single character under cursor
Nx     delete N characters, starting with character under cursor
dw     delete the single word beginning with character under cursor
dNw     delete N words beginning with character under cursor;
e.g., d5w deletes 5 words
D     delete the remainder of the line, starting with current cursor position
dd     delete entire current line
Ndd or dNd     delete N lines, beginning with the current line;
e.g., 5dd deletes 5 lines

Cutting and Pasting Text

yy     copy (yank, cut) the current line into the buffer
Nyy or yNy     copy (yank, cut) the next N lines, including the current line, into the buffer
p     put (paste) the line(s) in the buffer into the text after the current line

Searching Text

/string     search forward for occurrence of string in text
?string     search backward for occurrence of string in text
n     move to next occurrence of search string
N     move to next occurrence of search string in opposite direction

Determining Line Numbers

:.=     returns line number of current line at bottom of screen
:=     returns the total number of lines at bottom of screen
^g     provides the current line number, along with the total number of lines, in the file at the bottom of the screen

Saving and Reading Files

These commands permit you to input and output files other than the named file with which you are currently working.

:r your-filename<Enter>     read file named your-filename and insert after current line
:w<Enter>     write current contents to file named in original vi call
:w newfile<Enter>     write current contents to a new file named newfile
:12,35w smallfile<Enter>     write the contents of the lines numbered 12 through 35 to a new file named smallfile
:w! prevfile<Enter>     write current contents over a pre-existing file named prevfile