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Diffstat (limited to 'docs/manual/mod/mod_headers.html.en')
| -rw-r--r-- | docs/manual/mod/mod_headers.html.en | 304 |
1 files changed, 152 insertions, 152 deletions
diff --git a/docs/manual/mod/mod_headers.html.en b/docs/manual/mod/mod_headers.html.en index 54407dd4bf..7d3b7a456f 100644 --- a/docs/manual/mod/mod_headers.html.en +++ b/docs/manual/mod/mod_headers.html.en @@ -52,158 +52,6 @@ headers</td></tr> <li><img alt="" src="../images/down.gif" /> <a href="#examples">Examples</a></li> </ul><ul class="seealso"><li><a href="#comments_section">Comments</a></li></ul></div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="order" id="order">Order of Processing</a></h2> - - <p>The directives provided by <code class="module"><a href="../mod/mod_headers.html">mod_headers</a></code> can - occur almost anywhere within the server configuration, and can be - limited in scope by enclosing them in <a href="../sections.html">configuration sections</a>.</p> - - <p>Order of processing is important and is affected both by the - order in the configuration file and by placement in <a href="../sections.html#mergin">configuration sections</a>. These - two directives have a different effect if reversed:</p> - - <pre class="prettyprint lang-config">RequestHeader append MirrorID "mirror 12" -RequestHeader unset MirrorID</pre> - - - <p>This way round, the <code>MirrorID</code> header is not set. If - reversed, the MirrorID header is set to "mirror 12".</p> -</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="early" id="early">Early and Late Processing</a></h2> - <p><code class="module"><a href="../mod/mod_headers.html">mod_headers</a></code> can be applied either early or late - in the request. The normal mode is late, when <em>Request</em> Headers are - set immediately before running the content generator and <em>Response</em> - Headers just as the response is sent down the wire. Always use - Late mode in an operational server.</p> - - <p>Early mode is designed as a test/debugging aid for developers. - Directives defined using the <code>early</code> keyword are set - right at the beginning of processing the request. This means - they can be used to simulate different requests and set up test - cases, but it also means that headers may be changed at any time - by other modules before generating a Response.</p> - - <p>Because early directives are processed before the request path's - configuration is traversed, early headers can only be set in a - main server or virtual host context. Early directives cannot depend - on a request path, so they will fail in contexts such as - <code class="directive"><a href="../mod/core.html#directory"><Directory></a></code> or - <code class="directive"><a href="../mod/core.html#location"><Location></a></code>.</p> -</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> -<div class="section"> -<h2><a name="examples" id="examples">Examples</a></h2> - - <ol> - <li> - Copy all request headers that begin with "TS" to the - response headers: - - <pre class="prettyprint lang-config">Header echo ^TS</pre> - - </li> - - <li> - Add a header, <code>MyHeader</code>, to the response including a - timestamp for when the request was received and how long it - took to begin serving the request. This header can be used by - the client to intuit load on the server or in isolating - bottlenecks between the client and the server. - - <pre class="prettyprint lang-config">Header set MyHeader "%D %t"</pre> - - - <p>results in this header being added to the response:</p> - - <div class="example"><p><code> - MyHeader: D=3775428 t=991424704447256 - </code></p></div> - </li> - - <li> - Say hello to Joe - - <pre class="prettyprint lang-config">Header set MyHeader "Hello Joe. It took %D microseconds for Apache to serve this request."</pre> - - - <p>results in this header being added to the response:</p> - - <div class="example"><p><code> - MyHeader: Hello Joe. It took D=3775428 microseconds for Apache - to serve this request. - </code></p></div> - </li> - - <li> - Conditionally send <code>MyHeader</code> on the response if and - only if header <code>MyRequestHeader</code> is present on the request. - This is useful for constructing headers in response to some client - stimulus. Note that this example requires the services of the - <code class="module"><a href="../mod/mod_setenvif.html">mod_setenvif</a></code> module. - - <pre class="prettyprint lang-config">SetEnvIf MyRequestHeader myvalue HAVE_MyRequestHeader -Header set MyHeader "%D %t mytext" env=HAVE_MyRequestHeader</pre> - - - <p>If the header <code>MyRequestHeader: myvalue</code> is present on - the HTTP request, the response will contain the following header:</p> - - <div class="example"><p><code> - MyHeader: D=3775428 t=991424704447256 mytext - </code></p></div> - </li> - - <li> - Enable DAV to work with Apache running HTTP through SSL hardware - (<a href="http://svn.haxx.se/users/archive-2006-03/0549.shtml">problem - description</a>) by replacing <var>https:</var> with - <var>http:</var> in the <var>Destination</var> header: - - <pre class="prettyprint lang-config">RequestHeader edit Destination ^https: http: early</pre> - - </li> - - <li> - Set the same header value under multiple nonexclusive conditions, - but do not duplicate the value in the final header. - If all of the following conditions applied to a request (i.e., - if the <code>CGI</code>, <code>NO_CACHE</code> and - <code>NO_STORE</code> environment variables all existed for the - request): - - <pre class="prettyprint lang-config">Header merge Cache-Control no-cache env=CGI -Header merge Cache-Control no-cache env=NO_CACHE -Header merge Cache-Control no-store env=NO_STORE</pre> - - - <p>then the response would contain the following header:</p> - - <div class="example"><p><code> - Cache-Control: no-cache, no-store - </code></p></div> - - <p>If <code>append</code> was used instead of <code>merge</code>, - then the response would contain the following header:</p> - - <div class="example"><p><code> - Cache-Control: no-cache, no-cache, no-store - </code></p></div> - </li> - <li> - Set a test cookie if and only if the client didn't send us a cookie - <pre class="prettyprint lang-config">Header set Set-Cookie testcookie "expr=-z %{req:Cookie}"</pre> - - </li> - <li> - Append a Caching header for responses with a HTTP status code of 200 - <pre class="prettyprint lang-config">Header append Cache-Control s-maxage=600 "expr=%{REQUEST_STATUS} == 200"</pre> - - </li> - - </ol> -</div> -<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> <div class="directive-section"><h2><a name="Header" id="Header">Header</a> <a name="header" id="header">Directive</a></h2> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configure HTTP response headers</td></tr> @@ -544,6 +392,158 @@ available in 2.4.10 and later</td></tr> input filters to be overridden or modified.</p> </div> +<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="section"> +<h2><a name="order" id="order">Order of Processing</a></h2> + + <p>The directives provided by <code class="module"><a href="../mod/mod_headers.html">mod_headers</a></code> can + occur almost anywhere within the server configuration, and can be + limited in scope by enclosing them in <a href="../sections.html">configuration sections</a>.</p> + + <p>Order of processing is important and is affected both by the + order in the configuration file and by placement in <a href="../sections.html#mergin">configuration sections</a>. These + two directives have a different effect if reversed:</p> + + <pre class="prettyprint lang-config">RequestHeader append MirrorID "mirror 12" +RequestHeader unset MirrorID</pre> + + + <p>This way round, the <code>MirrorID</code> header is not set. If + reversed, the MirrorID header is set to "mirror 12".</p> +</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="section"> +<h2><a name="early" id="early">Early and Late Processing</a></h2> + <p><code class="module"><a href="../mod/mod_headers.html">mod_headers</a></code> can be applied either early or late + in the request. The normal mode is late, when <em>Request</em> Headers are + set immediately before running the content generator and <em>Response</em> + Headers just as the response is sent down the wire. Always use + Late mode in an operational server.</p> + + <p>Early mode is designed as a test/debugging aid for developers. + Directives defined using the <code>early</code> keyword are set + right at the beginning of processing the request. This means + they can be used to simulate different requests and set up test + cases, but it also means that headers may be changed at any time + by other modules before generating a Response.</p> + + <p>Because early directives are processed before the request path's + configuration is traversed, early headers can only be set in a + main server or virtual host context. Early directives cannot depend + on a request path, so they will fail in contexts such as + <code class="directive"><a href="../mod/core.html#directory"><Directory></a></code> or + <code class="directive"><a href="../mod/core.html#location"><Location></a></code>.</p> +</div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> +<div class="section"> +<h2><a name="examples" id="examples">Examples</a></h2> + + <ol> + <li> + Copy all request headers that begin with "TS" to the + response headers: + + <pre class="prettyprint lang-config">Header echo ^TS</pre> + + </li> + + <li> + Add a header, <code>MyHeader</code>, to the response including a + timestamp for when the request was received and how long it + took to begin serving the request. This header can be used by + the client to intuit load on the server or in isolating + bottlenecks between the client and the server. + + <pre class="prettyprint lang-config">Header set MyHeader "%D %t"</pre> + + + <p>results in this header being added to the response:</p> + + <div class="example"><p><code> + MyHeader: D=3775428 t=991424704447256 + </code></p></div> + </li> + + <li> + Say hello to Joe + + <pre class="prettyprint lang-config">Header set MyHeader "Hello Joe. It took %D microseconds for Apache to serve this request."</pre> + + + <p>results in this header being added to the response:</p> + + <div class="example"><p><code> + MyHeader: Hello Joe. It took D=3775428 microseconds for Apache + to serve this request. + </code></p></div> + </li> + + <li> + Conditionally send <code>MyHeader</code> on the response if and + only if header <code>MyRequestHeader</code> is present on the request. + This is useful for constructing headers in response to some client + stimulus. Note that this example requires the services of the + <code class="module"><a href="../mod/mod_setenvif.html">mod_setenvif</a></code> module. + + <pre class="prettyprint lang-config">SetEnvIf MyRequestHeader myvalue HAVE_MyRequestHeader +Header set MyHeader "%D %t mytext" env=HAVE_MyRequestHeader</pre> + + + <p>If the header <code>MyRequestHeader: myvalue</code> is present on + the HTTP request, the response will contain the following header:</p> + + <div class="example"><p><code> + MyHeader: D=3775428 t=991424704447256 mytext + </code></p></div> + </li> + + <li> + Enable DAV to work with Apache running HTTP through SSL hardware + (<a href="http://svn.haxx.se/users/archive-2006-03/0549.shtml">problem + description</a>) by replacing <var>https:</var> with + <var>http:</var> in the <var>Destination</var> header: + + <pre class="prettyprint lang-config">RequestHeader edit Destination ^https: http: early</pre> + + </li> + + <li> + Set the same header value under multiple nonexclusive conditions, + but do not duplicate the value in the final header. + If all of the following conditions applied to a request (i.e., + if the <code>CGI</code>, <code>NO_CACHE</code> and + <code>NO_STORE</code> environment variables all existed for the + request): + + <pre class="prettyprint lang-config">Header merge Cache-Control no-cache env=CGI +Header merge Cache-Control no-cache env=NO_CACHE +Header merge Cache-Control no-store env=NO_STORE</pre> + + + <p>then the response would contain the following header:</p> + + <div class="example"><p><code> + Cache-Control: no-cache, no-store + </code></p></div> + + <p>If <code>append</code> was used instead of <code>merge</code>, + then the response would contain the following header:</p> + + <div class="example"><p><code> + Cache-Control: no-cache, no-cache, no-store + </code></p></div> + </li> + <li> + Set a test cookie if and only if the client didn't send us a cookie + <pre class="prettyprint lang-config">Header set Set-Cookie testcookie "expr=-z %{req:Cookie}"</pre> + + </li> + <li> + Append a Caching header for responses with a HTTP status code of 200 + <pre class="prettyprint lang-config">Header append Cache-Control s-maxage=600 "expr=%{REQUEST_STATUS} == 200"</pre> + + </li> + + </ol> +</div> </div> <div class="bottomlang"> <p><span>Available Languages: </span><a href="../en/mod/mod_headers.html" title="English"> en </a> | |