<modulesynopsis>
<name>mod_env</name>
- <description>Modifies the environment which is
- passed to CGI scripts and SSI pages</description>
- <status>Base</status>
- <sourcefile>mod_env.c</sourcefile>
- <identifier>env_module</identifier>
- <summary>
+<description>Modifies the environment which is passed to CGI scripts and
+SSI pages</description>
+<status>Base</status>
+<sourcefile>mod_env.c</sourcefile>
+<identifier>env_module</identifier>
+<summary>
<p>This module allows for control of the environment that will
be provided to CGI scripts and SSI pages. Environment variables
may be passed from the shell which invoked the httpd process.
Alternatively, environment variables may be set or unset within
the configuration process.</p>
- </summary>
- <seealso><a href="../env.html">Environment Variables</a></seealso>
+</summary>
+<seealso><a href="../env.html">Environment Variables</a></seealso>
- <directivesynopsis>
- <name>PassEnv</name>
- <description>Passes environment variables from the shell</description>
- <syntax>PassEnv
- <em>env-variable</em> [<em>env-variable</em>] ...</syntax>
- <contextlist>
- <context>server config</context><context>virtual host</context>
- <context>directory</context><context>.htaccess</context>
- </contextlist>
- <override>FileInfo</override>
+<directivesynopsis>
+<name>PassEnv</name>
+<description>Passes environment variables from the shell</description>
+<syntax>PassEnv <var>env-variable</var> [<var>env-variable</var>]
+...</syntax>
+<contextlist><context>server config</context><context>virtual host</context>
+<context>directory</context><context>.htaccess</context></contextlist>
+<override>FileInfo</override>
<usage>
<p>Specifies one or more environment variables to pass to CGI
scripts and SSI pages from the environment of the shell which
- invoked the httpd process. Example:</p>
-<example>
- PassEnv LD_LIBRARY_PATH
-</example>
+ invoked the httpd process.</p>
+
+ <example><title>Example</title>
+ PassEnv LD_LIBRARY_PATH
+ </example>
</usage>
</directivesynopsis>
<directivesynopsis>
<name>SetEnv</name>
<description>Sets environment variables</description>
-<syntax>SetEnv <em>env-variable value</em></syntax>
-<contextlist>
-<context>server config</context><context>virtual host</context>
-<context>directory</context><context>.htaccess</context>
-</contextlist>
+<syntax>SetEnv <var>env-variable</var> <var>value</var></syntax>
+<contextlist><context>server config</context><context>virtual host</context>
+<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>
<usage>
<p>Sets an environment variable, which is then passed on to CGI
- scripts and SSI pages. Example:</p>
-<example>
- SetEnv SPECIAL_PATH /foo/bin
-</example>
+ scripts and SSI pages.</p>
+
+ <example><title>Example</title>
+ SetEnv SPECIAL_PATH /foo/bin
+ </example>
</usage>
</directivesynopsis>
<directivesynopsis>
<name>UnsetEnv</name>
<description>Removes variables from the environment</description>
-<syntax>UnsetEnv <em>env-variable</em> [<em>env-variable</em>] ...</syntax>
-<contextlist>
-<context>server config</context><context>virtual host</context>
-<context>directory</context><context>.htaccess</context>
-</contextlist>
+<syntax>UnsetEnv <var>env-variable</var> [<var>env-variable</var>]
+...</syntax>
+<contextlist><context>server config</context><context>virtual host</context>
+<context>directory</context><context>.htaccess</context></contextlist>
<override>FileInfo</override>
<usage>
<p>Removes one or more environment variables from those passed
- on to CGI scripts and SSI pages. Example:</p>
-<example>
- UnsetEnv LD_LIBRARY_PATH
-</example>
+ on to CGI scripts and SSI pages.</p>
+
+ <example><title>Example</title>
+ UnsetEnv LD_LIBRARY_PATH
+ </example>
</usage>
</directivesynopsis>
<modulesynopsis>
<name>mod_expires</name>
-<description>Generation of
- <code>Expires</code> HTTP headers according to user-specified
- criteria</description>
+<description>Generation of <code>Expires</code> HTTP headers according to
+user-specified criteria</description>
<status>Extension</status>
<sourcefile>mod_expires.c</sourcefile>
<identifier>expires_module</identifier>
must be obtained from the source.</p>
</summary>
-<section id="AltSyn"><title>Alternate Interval
- Syntax</title>
-
- <p>The <directive module="mod_expires">ExpiresDefault</directive> and
+<section id="AltSyn"><title>Alternate Interval Syntax</title>
+ <p>The <directive module="mod_expires">ExpiresDefault</directive> and
<directive module="mod_expires">ExpiresByType</directive> directives
can also be defined in a more readable syntax of the form:</p>
-<example>
- ExpiresDefault "<base> [plus] {<num>
+ <example>
+ ExpiresDefault "<base> [plus] {<num>
<type>}*"<br />
- ExpiresByType type/encoding "<base> [plus]
+ ExpiresByType type/encoding "<base> [plus]
{<num> <type>}*"
-</example>
+ </example>
<p>where <base> is one of:</p>
<li><code>modification</code></li>
</ul>
- <p>The '<code>plus</code>' keyword is optional. <num>
+ <p>The <code>plus</code> keyword is optional. <num>
should be an integer value [acceptable to <code>atoi()</code>],
and <type> is one of:</p>
<ul>
<li><code>years</code></li>
-
<li><code>months</code></li>
-
<li><code>weeks</code></li>
-
<li><code>days</code></li>
-
<li><code>hours</code></li>
-
<li><code>minutes</code></li>
-
<li><code>seconds</code></li>
</ul>
make documents expire 1 month after being accessed, by
default:</p>
-<example>
- ExpiresDefault "access plus 1 month"<br />
- ExpiresDefault "access plus 4 weeks"<br />
- ExpiresDefault "access plus 30 days"
-</example>
+ <example>
+ ExpiresDefault "access plus 1 month"<br />
+ ExpiresDefault "access plus 4 weeks"<br />
+ ExpiresDefault "access plus 30 days"
+ </example>
<p>The expiry time can be fine-tuned by adding several
'<num> <type>' clauses:</p>
-<example>
-ExpiresByType text/html "access plus 1 month 15
+ <example>
+ ExpiresByType text/html "access plus 1 month 15
days 2 hours"<br />
- ExpiresByType image/gif "modification plus 5 hours 3
+ ExpiresByType image/gif "modification plus 5 hours 3
minutes"
-</example>
+ </example>
<p>Note that if you use a modification date based setting, the
Expires header will <strong>not</strong> be added to content
<directivesynopsis>
<name>ExpiresActive</name>
-<description>Enables generation of <code>Expires</code> headers</description>
+<description>Enables generation of <code>Expires</code>
+headers</description>
<syntax>ExpiresActive On|Off</syntax>
<contextlist><context>server config</context>
<context>virtual host</context><context>directory</context>
<code>Expires</code> header for the document realm in question.
(That is, if found in an <code>.htaccess</code> file, for
instance, it applies only to documents generated from that
- directory.) If set to <em><code>Off</code></em>, no
- <code>Expires</code> header will be generated for any document
- in the realm (unless overridden at a lower level, such as an
- <code>.htaccess</code> file overriding a server config file).
- If set to <em><code>On</code></em>, the header will be added to
- served documents according to the criteria defined by the
+ directory.) If set to <code>Off</code>, no <code>Expires</code> header
+ will be generated for any document in the realm (unless overridden at
+ a lower level, such as an <code>.htaccess</code> file overriding a
+ server config file). If set to <code>On</code>, the header will be
+ added to served documents according to the criteria defined by the
<directive module="mod_expires">ExpiresByType</directive> and
<directive module="mod_expires">ExpiresDefault</directive> directives
(<em>q.v.</em>).</p>
<name>ExpiresByType</name>
<description>Value of the <code>Expires</code> header configured
by MIME type</description>
-<syntax>ExpiresByType
- <em>MIME-type <code>seconds</em></syntax>
-<contextlist><context>server config</context>
-<context>virtual host</context><context>directory</context>
-<context>.htaccess</context></contextlist>
+<syntax>ExpiresByType <var>MIME-type</var>
+<var><code>seconds</var></syntax>
+<contextlist><context>server config</context><context>virtual host</context>
+<context>directory</context><context>.htaccess</context></contextlist>
<override>Indexes</override>
<usage>
<p>This directive defines the value of the <code>Expires</code>
- header generated for documents of the specified type
- (<em>e.g.</em>, <code>text/html</code>). The second argument
- sets the number of seconds that will be added to a base time to
- construct the expiration date.</p>
+ header generated for documents of the specified type (<em>e.g.</em>,
+ <code>text/html</code>). The second argument sets the number of
+ seconds that will be added to a base time to construct the expiration
+ date.</p>
<p>The base time is either the last modification time of the
file, or the time of the client's access to the document. Which
should be used is specified by the
- <code><em><code></em></code> field; <strong>M</strong>
+ <code><var><code></var></code> field; <code>M</code>
means that the file's last modification time should be used as
- the base time, and <strong>A</strong> means the client's access
+ the base time, and <code>A</code> means the client's access
time should be used.</p>
- <p>The difference in effect is subtle. If <em>M</em> is used,
+ <p>The difference in effect is subtle. If <code>M</code> is used,
all current copies of the document in all caches will expire at
the same time, which can be good for something like a weekly
- notice that's always found at the same URL. If <em>A</em> is
+ notice that's always found at the same URL. If <code>A</code> is
used, the date of expiration is different for each client; this
can be good for image files that don't change very often,
particularly for a set of related documents that all refer to
the same images (<em>i.e.</em>, the images will be accessed
repeatedly within a relatively short timespan).</p>
- <p><strong>Example:</strong></p>
-<example>
-# enable expirations<br />
-ExpiresActive On<br />
-# expire GIF images after a month in the client's cache<br />
-ExpiresByType image/gif A2592000<br />
-# HTML documents are good for a week from the time they were changed<br />
-ExpiresByType text/html M604800
-</example>
+ <example><title>Example:</title>
+ # enable expirations<br />
+ ExpiresActive On<br />
+ # expire GIF images after a month in the client's cache<br />
+ ExpiresByType image/gif A2592000<br />
+ # HTML documents are good for a week from the<br />
+ # time they were changed<br />
+ ExpiresByType text/html M604800
+ </example>
<p>Note that this directive only has effect if
<code>ExpiresActive On</code> has been specified. It overrides,
<directivesynopsis>
<name>ExpiresDefault</name>
<description>Default algorithm for calculating expiration time</description>
-<syntax>ExpiresDefault <em><code>seconds</em></syntax>
-<contextlist><context>server config</context>
-<context>virtual host</context><context>directory</context>
-<context>.htaccess</context></contextlist>
+<syntax>ExpiresDefault <var><code>seconds</var></syntax>
+<contextlist><context>server config</context><context>virtual host</context>
+<context>directory</context><context>.htaccess</context></contextlist>
<override>Indexes</override>
<usage>