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| author | Rich Bowen <rbowen@apache.org> | 2001-09-22 19:39:26 +0000 |
|---|---|---|
| committer | Rich Bowen <rbowen@apache.org> | 2001-09-22 19:39:26 +0000 |
| commit | f88b50dec40878abeccce0e1b9cfc6780a4b1465 (patch) | |
| tree | 84e6a7b926e102d9f322b96351f2346be29c2db5 /docs/manual/mod/mod_expires.html | |
| parent | 651abc3a73acadb00f390b58ed4e5b7ebb14d2b0 (diff) | |
| download | httpd-f88b50dec40878abeccce0e1b9cfc6780a4b1465.tar.gz | |
w3c tidy to convert to xhtml
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@91116 13f79535-47bb-0310-9956-ffa450edef68
Diffstat (limited to 'docs/manual/mod/mod_expires.html')
| -rw-r--r-- | docs/manual/mod/mod_expires.html | 598 |
1 files changed, 254 insertions, 344 deletions
diff --git a/docs/manual/mod/mod_expires.html b/docs/manual/mod/mod_expires.html index c80b194ae0..bae83e9873 100644 --- a/docs/manual/mod/mod_expires.html +++ b/docs/manual/mod/mod_expires.html @@ -1,350 +1,260 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> -<HTML> - <HEAD> - <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> - <P> - <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 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> - <MENU> - <LI><SAMP>access</SAMP> - </LI> - <LI><SAMP>now</SAMP> (equivalent to '<SAMP>access</SAMP>') - </LI> - <LI><SAMP>modification</SAMP> - </LI> - </MENU> - <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> - <MENU> - <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> - </MENU> - <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. - - <HR> - <H2><A NAME="expiresactive"> - ExpiresActive directive - </A></H2> - <!--%plaintext <?INDEX {\tt ExpiresActive} directive> --> - <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 NAME="expiresbytype"> - ExpiresByType directive - </A></H2> - <!--%plaintext <?INDEX {\tt ExpiresByType} directive> --> - <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> - <P> - <PRE> +<!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> + <!--%plaintext <?INDEX {\tt ExpiresActive} directive> --> + + <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> + <!--%plaintext <?INDEX {\tt ExpiresByType} directive> --> + + <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> - <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 NAME="expiresdefault"> - ExpiresDefault directive - </A></H2> - <!--%plaintext <?INDEX {\tt ExpiresDefault} directive> --> - <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> + +</pre> + <br /> + <br /> + + + <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> + <!--%plaintext <?INDEX {\tt ExpiresDefault} directive> --> + + <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> + |