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<manualpage metafile="flags.xml.meta">
<parentdocument href="/index.html"/>
<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 %{REQUEST_URI} \.(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_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>Type flag</p>
</section>
</section>
</manualpage>