A small yet handy cheat sheet for mod_rewrite. The most used items to build a mod_rewrite pattern.

Despite the tons of examples and docs, mod_rewrite is voodoo. Damned cool voodoo, but still voodoo.

Layout

RewriteRule Pattern Substituion [Flag(s)]

Example of rewriting oldfiles to new files:

RewriteRule &/oldfile\.html$ /newfile.html

Operators

.	Every char
< > =	Compare
\	Escape a char
.+	One more, more chars
.*	No chars or multiple chars
^	Start
$	End
(…)	Group
a|b	.A or B
(a|b)	.A or B group
a{5}	Exact 5 times a
a{1,5}	Between 1 and 5 times a
[a-z]*	Match chars
-d	Directory
-f	File
-l	Symbolic link

Flags

[NC]	No case sensitive
[OR]	Allows multiple lines
[R=#]	Redirect where # is number: 404.
[L]	Terminate routine

RewriteCond variables

%{HTTP_ACCEPT}	Media types accepted by the client, ?text/plain?
%{HTTP_COOKIE}	Cookies set for the client.
%{HTTP_HOST}	Domain name of the virtual host queried.
%{HTTP_REFERER}	Page with a link to this page (can be omitted).
%{HTTP_USER_AGENT}	Client, such as ?Mozilla/4.0?
%{QUERY_STRING}	Query string transferred by a GET form.
%{REMOTE_ADDR}	Client IP address.
%{REMOTE_HOST}	Domain name of client.
%{REMOTE_USER}	User name of the client.
%{REQUEST_URI}	The URI requested by the client.
%{REQUEST_FILENAME}	The corresponding file on the local file system.
%{SERVER_ADDR}	Server IP