vi change Commands

Making and Undoing Changes

There are a lot of ways to change, remove or replace text in vi.  The following commands allow specific changes to be made, and perhaps most useful, undo changes that have been made.

Command	Action
x	Delete one character
r	Replace one character with the next character typed
dw	Delete from the cursor position to the end of the current word
dd	Delete the current line
D	Delete from the current character to the end of this line
cw	Same as dw then enter insert mode
cc	Clear the text on this line and enter insert mode
C	Delete from the current cursor position to the end of the current line and enter insert mode
J	Join the next line to the current line
u	Undo the last change.  Can be repeated to undo the past several changes.
.	Repeat the last edit command at the current cursor position

Like the cursor movement commands, many of these commands can be preceded with a number to repeat the given command.  Even the undo comman can be preceded by a number to undo several recent commands.

Copying and Pasting

vi offers many options for copying and pasting including the ability to copy and paste from multiple buffers (a buffer is similar to the clipboard in Windows or Mac OS), but the basic copy and paste commands will only be touched upon.  The following commands allow you to copy and paste.

Command	Action
yy	Copy the current line into the default buffer
7yy	Copy the current line plus the next six lines to the default buffer
p	Paste the contents of the default buffer below the current line
P	Paste the contents of the default buffer above the current line

If multiple lines are copied with the yy command, the number of lines does not need to be specified when pasting.  The paste commandautomatically pastes the entire contents of the default buffer.

Searching and Replacing

Searching for text and replacing text in vi can be very handy, but it is not as easy as you might think!  Here are some of the more useful search and replace commands in vi: 

Command	Action
/search text	Find and move the cursor to the next occurrence of search text
'search text	Find and move the cursor to the previous occurrence of search text
n	Repeat the last search
N	Repeat the last search but in the opposite direction (previous occurrence instead of next or next occurrence instead of previous)
:%s/search text/replace text/g	Find all occurrences of search text and replace it with replace text
:noh	Turn off highlighting of searched for text

When these commands encounter the end of the file, they wrap around to the beginning and continue searching.  If searching backwards, they wrap from the beginning to the end.  It has probably been noticed that the find and replace command is very complicated.  There are ways of making it even more complicated and having it search only specific lines, but that level of complexity is not particularly needed.

Saving and Exiting

Work should be saved often and when all is done, exit vi.  As with other things in vi, there are several ways to save and exit.  Here are a few common ones:

Command	Action
:w	Save changes
:w filename.txt	Save changes to filename.txt instead of the file opened
:q	Exit vi (changes should have already been saved)
:q!	Exit vi without saving changes
:wq	Save changes and exit vi
ZZ	Save changes and exit vi (same as :wq)
:w!	Write changes despite read-only permissions (must be file owner)

This short section is only a brief introduction to vi, but it should be enough to do basic editing and some shell scripting.  vi allows text to be manipulated in just about any way imaginable, so if there is something specific that is to be done in vi, take a look through the help documents available by entering :help within vi or in an easier-to-navigate form on the Web at http://vimdoc.sourceforge.net.