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diff --git a/APACHE_1_3_42/htdocs/manual/mod/mod_expires.html b/APACHE_1_3_42/htdocs/manual/mod/mod_expires.html new file mode 100644 index 0000000000..ce131544c9 --- /dev/null +++ b/APACHE_1_3_42/htdocs/manual/mod/mod_expires.html @@ -0,0 +1,254 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> + +<html xmlns="http://www.w3.org/1999/xhtml"> + <head> + <meta name="generator" content="HTML Tidy, see www.w3.org" /> + + <title>Apache module mod_expires</title> + </head> + <!-- Background white, links blue (unvisited), navy (visited), red (active) --> + + <body bgcolor="#FFFFFF" text="#000000" link="#0000FF" + vlink="#000080" alink="#FF0000"> + <!--#include virtual="header.html" --> + + <h1 align="CENTER">Module mod_expires</h1> + + <p>This module provides for the generation of + <code>Expires</code> HTTP headers according to user-specified + criteria.</p> + + <p><a href="module-dict.html#Status" + rel="Help"><strong>Status:</strong></a> Extension<br /> + <a href="module-dict.html#SourceFile" + rel="Help"><strong>Source File:</strong></a> + mod_expires.c<br /> + <a href="module-dict.html#ModuleIdentifier" + rel="Help"><strong>Module Identifier:</strong></a> + expires_module<br /> + <a href="module-dict.html#Compatibility" + rel="Help"><strong>Compatibility:</strong></a> Available in + Apache 1.2 and later.</p> + + <h2>Summary</h2> + + <p>This module controls the setting of the <code>Expires</code> + HTTP header in server responses. The expiration date can set to + be relative to either the time the source file was last + modified, or to the time of the client access.</p> + + <p>The <code>Expires</code> HTTP header is an instruction to + the client about the document's validity and persistence. If + cached, the document may be fetched from the cache rather than + from the source until this time has passed. After that, the + cache copy is considered "expired" and invalid, and a new copy + must be obtained from the source.</p> + + <h2>Directives</h2> + + <ul> + <li><a href="#expiresactive">ExpiresActive</a></li> + + <li><a href="#expiresbytype">ExpiresByType</a></li> + + <li><a href="#expiresdefault">ExpiresDefault</a></li> + </ul> + + <h2><a id="AltSyn" name="AltSyn">Alternate Interval + Syntax</a></h2> + + <p>The <a + href="#expiresdefault"><samp>ExpiresDefault</samp></a> and <a + href="#expiresbytype"><samp>ExpiresByType</samp></a> directives + can also be defined in a more readable syntax of the form:</p> + + <dl> + <dd><code>ExpiresDefault "<base> [plus] {<num> + <type>}*"<br /> + ExpiresByType type/encoding "<base> [plus] + {<num> <type>}*"</code></dd> + </dl> + + <p>where <base> is one of:</p> + + <ul> + <li><samp>access</samp></li> + + <li><samp>now</samp> (equivalent to + '<samp>access</samp>')</li> + + <li><samp>modification</samp></li> + </ul> + + <p>The '<samp>plus</samp>' keyword is optional. <num> + should be an integer value [acceptable to <samp>atoi()</samp>], + and <type> is one of:</p> + + <ul> + <li><samp>years</samp></li> + + <li><samp>months</samp></li> + + <li><samp>weeks</samp></li> + + <li><samp>days</samp></li> + + <li><samp>hours</samp></li> + + <li><samp>minutes</samp></li> + + <li><samp>seconds</samp></li> + </ul> + + <p>For example, any of the following directives can be used to + make documents expire 1 month after being accessed, by + default:</p> + + <dl> + <dd><code>ExpiresDefault "access plus 1 month"<br /> + ExpiresDefault "access plus 4 weeks"<br /> + ExpiresDefault "access plus 30 days"</code></dd> + </dl> + + <p>The expiry time can be fine-tuned by adding several + '<num> <type>' clauses:</p> + + <dl> + <dd><code>ExpiresByType text/html "access plus 1 month 15 + days 2 hours"<br /> + ExpiresByType image/gif "modification plus 5 hours 3 + minutes"</code></dd> + </dl> + + <p>Note that if you use a modification date based setting, the + Expires header will <strong>not</strong> be added to content + that does not come from a file on disk. This is due to the fact + that there is no modification time for such content.</p> + <hr /> + + <h2><a id="expiresactive" name="expiresactive">ExpiresActive + directive</a></h2> + + <p><a href="directive-dict.html#Syntax" + rel="Help"><strong>Syntax:</strong></a> ExpiresActive + on|off<br /> + <a href="directive-dict.html#Context" + rel="Help"><strong>Context:</strong></a> server config, virtual + host, directory, .htaccess<br /> + <a href="directive-dict.html#Override" + rel="Help"><strong>Override:</strong></a> Indexes<br /> + <a href="directive-dict.html#Status" + rel="Help"><strong>Status:</strong></a> Extension<br /> + <a href="directive-dict.html#Module" + rel="Help"><strong>Module:</strong></a> mod_expires</p> + + <p>This directive enables or disables the generation of the + <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 <a + href="#expiresbytype">ExpiresByType</a> and <a + href="#expiresdefault">ExpiresDefault</a> directives + (<em>q.v.</em>).</p> + + <p>Note that this directive does not guarantee that an + <code>Expires</code> header will be generated. If the criteria + aren't met, no header will be sent, and the effect will be as + though this directive wasn't even specified.</p> + <hr /> + + <h2><a id="expiresbytype" name="expiresbytype">ExpiresByType + directive</a></h2> + + <p><a href="directive-dict.html#Syntax" + rel="Help"><strong>Syntax:</strong></a> ExpiresByType + <em>mime-type <code>seconds</em><br /> + <a href="directive-dict.html#Context" + rel="Help"><strong>Context:</strong></a> server config, virtual + host, directory, .htaccess<br /> + <a href="directive-dict.html#Override" + rel="Help"><strong>Override:</strong></a> Indexes<br /> + <a href="directive-dict.html#Status" + rel="Help"><strong>Status:</strong></a> Extension<br /> + <a href="directive-dict.html#Module" + rel="Help"><strong>Module:</strong></a> mod_expires</p> + + <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> + + <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> + means that the file's last modification time should be used as + the base time, and <strong>A</strong> means the client's access + time should be used.</p> + + <p>The difference in effect is subtle. If <em>M</em> 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 + 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> +<pre> + ExpiresActive On # enable expirations + ExpiresByType image/gif A2592000 # expire GIF images after a month + # in the client's cache + ExpiresByType text/html M604800 # HTML documents are good for a + # week from the time they were + # changed, period + +</pre> + + <p>Note that this directive only has effect if + <code>ExpiresActive On</code> has been specified. It overrides, + for the specified MIME type <em>only</em>, any expiration date + set by the <a href="#expiresdefault">ExpiresDefault</a> + directive.</p> + + <p>You can also specify the expiration time calculation using + an <a href="#AltSyn">alternate syntax</a>, described later in + this document.</p> + <hr /> + + <h2><a id="expiresdefault" name="expiresdefault">ExpiresDefault + directive</a></h2> + + <p><a href="directive-dict.html#Syntax" + rel="Help"><strong>Syntax:</strong></a> ExpiresDefault + <em><code>seconds</em><br /> + <a href="directive-dict.html#Context" + rel="Help"><strong>Context:</strong></a> server config, virtual + host, directory, .htaccess<br /> + <a href="directive-dict.html#Override" + rel="Help"><strong>Override:</strong></a> Indexes<br /> + <a href="directive-dict.html#Status" + rel="Help"><strong>Status:</strong></a> Extension<br /> + <a href="directive-dict.html#Module" + rel="Help"><strong>Module:</strong></a> mod_expires</p> + + <p>This directive sets the default algorithm for calculating + the expiration time for all documents in the affected realm. It + can be overridden on a type-by-type basis by the <a + href="#expiresbytype">ExpiresByType</a> directive. See the + description of that directive for details about the syntax of + the argument, and the <a href="#AltSyn">alternate syntax</a> + description as well.</p> + <!--#include virtual="footer.html" --> + </body> +</html> + |