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<title>Apache mod_rewrite Flags</title>

<summary>

<p>This document discusses the flags which are available to the

<directive module="mod_rewrite">RewriteRule</directive> directive,

providing more detailed explanations and examples of each.</p>

</summary>

<seealso><a href="/mod/mod_rewrite.html">Module documentation</a></seealso>

<seealso><a href="rewrite_tech.html">Technical details</a></seealso>

<seealso><a href="rewrite_guide.html">Rewrite Guide - useful examples</a></seealso>

<seealso><a href="rewrite_guide_advanced.html">Advanced Rewrite Guide -

advanced useful examples</a></seealso>

<section id="introduction"><title>Introduction</title>

<p><directive module="mod_rewrite">RewriteRule</directive>s can have

their behavior modified by one or more flags. Flags are included in

square brackets at the end of the rule, and multiple flags are separated

by commas.</p>

<example>

RewriteRule pattern target [Flag1,Flag2,Flag3]

</example>

<p>The flags all have a short form, such as <code>CO</code>, as well as

a longer form, such as <code>cookie</code>. Some flags take one or more

arguments. Flags are not case sensitive.</p>

</section>

<section id="flags"><title>The flags</title>

<p>Each flag has a long and short form. While it is most common to use

the short form, it is recommended that you familiarize yourself with the

long form, so that you remember what each flag is supposed to do.</p>

<p>Presented here are each of the available flags, along with an example

of how you might use them.</p>

<section id="flag_c"><title>C|chain</title>

<p>The [C] or [chain] flag indicates that the <directive

module="mod_rewrite">RewriteRule</directive> is chained to the next

rule. That is, if the rule matches, then it is processed as usual and

control moves on to the next rule. However, if it does not match, then

the next rule, and any other rules that are chained together, will be

skipped.</p>

</section>

<section id="flag_co"><title>CO|cookie</title>

<p>The [CO], or [cookie] flag, allows you to set a cookie when a

particular <directive module="mod_rewrite">RewriteRule</directive>

matches. The argument consists of three required fields and two optional

fields.</p>

<p>You must declare a name and value for the cookie to be set, and the

domain for which you wish the cookie to be valid. You may optionally set

the lifetime of the cookie, and the path for which it should be

returned.</p>

<p>By default, the lifetime of the cookie is the current browser

session.</p>

<p>By default, the path for which the cookie will be valid is "/" - that

is, the entire website.</p>

<p>Several examples are offered here:</p>

<example>

RewriteEngine On<br />

RewriteRule ^/index.html - [CO=frontdoor=yes:.apache.org:1440:/]

</example>

<p>This rule doesn't rewrite the request (the "-" rewrite target tells

mod_rewrite to pass the request through unchanged) but sets a cookie

called 'frontdoor' to a value of 'yes'. The cookie is valid for any host

in the <code>.apache.org</code> domain. It will be set to expire in 1440

minutes (24 hours) and will be returned for all URIs.</p>

</section>

<section id="flag_e"><title>E|env</title>

<p>With the [E], or [env] flag, you can set the value of an environment

variable. Note that some environment variables may be set after the rule

is run, thus unsetting what you have set. See <a href="/env.html">the

Environment Variables document</a> for more details on how Environment

variables work.</p>

<p>The following example sets an evironment variable called 'image' to a

value of '1' if the requested URI is an image file. Then, that

environment variable is used to exclude those requests from the access

log.</p>

<example>

RewriteRule \.(png|gif|jpg) - [E=image:1]<br />

CustomLog logs/access_log combined env=!image

</example>

<p>Note that this same effect can be obtained using <directive

module="mod_setenvif">SetEnvIf</directive>. This technique is offered as

an example, not as a recommendation.</p>

</section>

<section id="flag_f"><title>F|forbidden</title>

<p>Using the [F] flag causes Apache to return a 403 Forbidden status

code to the client. While the same behavior can be accomplished using

the <directive module="mod_access">Deny</directive> directive, this

allows more flexibility in assigning a Forbidden status.</p>

<p>The following rule will forbid <code>.exe</code> files from being

downloaded from your server.</p>

<example>

RewriteRule \.exe - [F]

</example>

<p>This rule uses the "-" syntax for the rewrite target, which means

that the requested URI is not modified.</p>

</section>

<section id="flag_g"><title>G|gone</title>

<p>Gone flag</p>

</section>

<section id="flag_h"><title>H|handler</title>

<p>Handler flag</p>

</section>

<section id="flag_l"><title>L|last</title>

<p>Last flag</p>

</section>

<section id="flag_n"><title>N|next</title>

<p>Next round flag</p>

</section>

<section id="flag_nc"><title>NC|nocase</title>

<p>Use of the [NC] flag causes the <directive

module="mod_rewrite">RewriteRule</directive> to be matched in a

case-insensitive manner. That is, it doesn't care whether letters appear

as upper-case or lower-case in the matched URI.</p>

<p>In the example below, any request for an image file will be proxied

to your dedicated image server. The match is case-insensitive, so that

<code>.jpg</code> and <code>.JPG</code> files are both acceptable, for

example.</p>

<example>

RewriteRule (.*\.(jpg|gif|png))$ http://images.example.com$1 [P,NC]

</example>

</section>

<section id="flag_ne"><title>NE|noescape</title>

<p>No escape flag</p>

</section>

<section id="flag_ns"><title>NS|nosubreq</title>

<p>No internal subrequest flag</p>

</section>

<section id="flag_p"><title>P|proxy</title>

<p>Proxy flag</p>

</section>

<section id="flag_pt"><title>PT|passthrough</title>

<p>Passthrough flag</p>

</section>

<section id="flag_qsa"><title>QSA|qsappend</title>

<p>Query String Append flag</p>

</section>

<section id="flag_r"><title>R|redirect</title>

<p>Redirect flag</p>

</section>

<section id="flag_s"><title>S|skip</title>

<p>The [S] flag is used to skip rules that you don't want to run. This

can be thought of as a <code>goto</code> statement in your rewrite

ruleset. In the following example, we only want to run the <directive

module="mod_rewrite">RewriteRule</directive> if the requested URI

doesn't correspond with an actual file.</p>

<example>

RewriteCond %{REQUEST_FILENAME} !-f<br />

RewriteCond %{REQUEST_FILENAME} !-d<br />

RewriteRule .? - [S=2]<br />

<br />

RewriteRule (.*\.gif) images.php?$1<br />

RewriteRule (.*\.html) docs.php?$1

</example>

<p>This technique is useful because a <directive

module="mod_rewrite">RewriteCond</directive> only applies to the

<directive module="mod_rewrite">RewriteRule</directive> immediately

following it. Thus, if you want to make a <code>RewriteCond</code> apply

to several <code>RewriteRule</code>s, one possible technique is to

negate those conditions and use a [Skip] flag.</p>

</section>

<section id="flag_t"><title>T|type</title>

<p>Sets the MIME type with which the resulting response will be

sent. This has the same effect as the <directive

module="mod_mime">AddType</directive> directive.</p>

<p>For example, you might use the following technique to serve Perl

source code as plain text, if requested in a particular way:</p>

<example>

# Files with 'IMG' in the name are gif images.

RewriteRule IMG - [T=image/gif]

</example>

<p>Please note that this is a trivial example, and could be better done

using &lt;FilesMatch&gt; instead. Always consider the alternate

solutions to a problem before resorting to rewrite, which will

invariably be a less efficient solution than the alternatives.</p>

</section>

</section>

</manualpage>