My VI cheat sheet

The VI editor is an indispensable tool for any UNIX system administrator. In this post I'd like to share some of the common vi commands & options that I use or try to use on a routine basis.


Leaving vi:

shift +zz -> write & quit.
wq -> write & save
q! -> quit without saving.
:w filename -> save ac copy of the currently open file with a new name.

vi modes:

command mode -> aAiIoOc -> inset mode
command mode  <- ESC <- insert mode
command mode -> : ! / ? -> promtpt/ex mode
command mode <- press enter <- promtpt/ex mode


Copying command sequences:

Copy an example command sequence: jhhkkkkll
The commands get copied to OSs' clipboard
Open a file in vi & while in command mode right click to paste the copied command sequence.
The result is that vi executes the command sequence.

Open multiple files for editing in a single vi command:

:n -> go to next file
:N -> go to previous file
:rew -> rewind to first file.
:r -> read a file into current file.



Basic cursor movement:

h -> move cursor left
l -> move cursor right
j -> down 1 line from current character
k -> up 1 line from current character

Moving around b/w text:

w -> forward a word
b -> backward a word
e -> forward to end of current word
) -> forward a sentence
( -> backward a sentence
} -> forward a paragraph
{ -> backward a paragraph

Note:
vi assumes end of sentences by . & paragraph changes by blank lines.
You can prefix a number before the movement commands


Moving by lines:

^ -> move cursor to beginning of current line
0 -> move cursor to beginning of current line
$ -> move cursor to end of current line
1G -> move to first line
G -> move to end of file
nG -> move to nth line of file
% -> matching paren/braces
ctrl+g -> display file status & line number


Scrolling:

ctrl+d -> scroll down half a screen
ctrl+u -> scroll up half a screen
ctrl+f -> scroll forward by a screen
ctrl+b -> scroll backward by a screen


Inserting text:

i -> insert before cursor
I -> insert at beginning of line
a -> append after cursor
A -> append at the end of line
o -> open a new line below current line
O -> open a new line above current line

File Management:

:w -> write without quitting
:q -> quit without writing.
:q! -> quit without saving changes.


Deleting text:

x -> delete current character
dd -> delete current line
dw -> delete current word
d^ -> delete to beginning of line
d$ -> delete to end of line

Note:
You can prefix a number before the deletion commands


Changing text:

r -> r followed by character replaces current character with the character typed with r
R -> override mode i.e the characters you type replace the characters already present on the cursor prompt.
~ -> changes case of current characters on the cursor


Undo, redo & repeat:

u -> undoes last change
ctrl+r -> redoes last change (undoes undo)
U -> undoes all changes on current line
. -> repeats last change


Delete, yank & put:

dd -> delete (cut) the line
yy -> copy the line
dx -> delete an amount
yx -> copy an amount
y$ -> copy from cursor position to end of the line
y^ -> copy from cursor position to beginning of the line
p -> put after cursor
P -> put before cursor

Note:
delete & yank go into vi's buffers & the buffer holds only the most recent yank/delete
As with delete, y can use a number or movement command


Searching text:

/ -> search for a pattern

Using regex in search patterns:

. -> a search for a.c yields abc or aec i.e. the . (dot) replaces exactly one character.
\ -> the backslash is used to remove special meaning of special characters like ., $ & ^
^string -> search for lines beginning with the searched string.
$string -> search for lines ending with the searched string.
[] -> matches a character set. The expression in the brackets stands for a single character in the set.


Search & replace:

:%s/old/new/g -> replaces every occurance of old with new in the entire file.
:%s/the[ym]/(&)/g -> enclose the search results in parenthesis throughout the file.
:%s/\(he\) \(is\)/\2 \1/ -> replace all occurances of 'he is' with 'is he'.

Indenting:

>> -> incdents current line (inserts a tab)
<< -> outdents current line (removes a tab)

Note:
Both >> & << can use a number prefix to indent/outdent multiple lines.


Filtering through shell commands:

!! ->  filters current line through shell command
n!! -> filters n lines
!% -> filters to matching pattern
!{ -> filters previous paragraph
!} -> filters next paragraph

Although this is a cheat sheet but I feel the need to elaborate on filtering. Vi allows the usage to any shell command that accepts some type of text as input, manipulate the text & provide output.
This way we can use the text manipulation capabilities of awk, sed & tr from within vi.

Using lines & line ranges in colon commands:

: line [,line] command -> performs commands on lines specified.
n -> line number
. -> current line
$ -> last line of file
/regex/ -> regular expression
% -. all lines.


Here are a couple of examples:

:%>> -> indent all lines.
:.,$ ! tr a-z A-Z -> change all lines between current line & last line of the file to upper case.
: /the/, /end/ d -> delete everything between the strings 'the' & 'end'