vim: Search & Replace

The vim search and replace command is of the form:

:range s[ubstitute]/pattern/string/cgiI

The command for each line in the range replaces a match of the pattern with the string.

Where range can be:

number	an absolute line number
.	the current line
$	the last line in the file
%	the whole file. The same as 1,$
't	position of mark "t"
/pattern[/]	the next line where text "pattern" matches.
?pattern[?]	the previous line where text "pattern" matches
\/	the next line where the previously used search pattern matches ("\" "/")
\?	the previous line where the previously used search pattern matches
\&	the next line where the previously used substitute pattern matches

Please note:

• You can mark your current position in the text by typing "mt", where "t" can be any letter, and use it as a mark later defining the line address.
• If no line range is specified the command will operate on the current line only.

And where pattern consists of anchors, metacharacters and quantifiers:
Anchors:

\<>	Word boundary de-limiters
^	Beginning of the line
$	End of the line

Metacharacters:

.	any character except new line
\s	whitespace character	\S	non-whitespace character
\d	digit	\D	non-digit
\x	hex digit	\X	non-hex digit
\o	octal digit	\O	non-octal digit
\h	head of word character (a,b,c...z,A,B,C...Z and _)	\H	non-head of word character
\p	printable character	\P	like \p, but excluding digits
\w	word character	\W	non-word character
\a	alphabetic character	\A	non-alphabetic character
\l	lowercase character	\L	non-lowercase character
\u	uppercase character	\U	non-uppercase character

Quantifiers may be greedy or non-greedy.

Here are the greedy ones: (here n and m are positive integers)

*	matches 0 or more of the preceding characters, ranges or metacharacters .* matches everything including empty line
\+	matches 1 or more of the preceding characters...
\=	matches 0 or 1 more of the preceding characters...
\{n,m}	matches from n to m of the preceding characters...
\{n}	matches exactly n times of the preceding characters...
\{,m}	matches at most m (from 0 to m) of the preceding characters...
\{n,}	matches at least n of of the preceding characters...

and here are the non-greedy quantifiers:

\{-}	matches 0 or more of the preceding atom, as few as possible
\{-n,m}	matches 1 or more of the preceding characters...
\{-n,}	matches at least 1 or more of the preceding characters...
\{-,m}	matches 1 or more of the preceding characters...

Finally the "search and replace command" may be followed by:

c	Confirm each substitution
g	Replace all occurrences in the line (without g - only first).
i	Ignore case for the pattern.
I	Don't ignore case for the pattern.

This is just an extract from:
http://larc.ee.nthu.edu.tw/~cthuang/vim/files/vim-regex/vim-regex.htm
For detailed usage visit the link.