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Diffstat (limited to 'docs/manual/mod/mod_headers.html.en')
| -rw-r--r-- | docs/manual/mod/mod_headers.html.en | 88 |
1 files changed, 56 insertions, 32 deletions
diff --git a/docs/manual/mod/mod_headers.html.en b/docs/manual/mod/mod_headers.html.en index 9a113518..a909f482 100644 --- a/docs/manual/mod/mod_headers.html.en +++ b/docs/manual/mod/mod_headers.html.en @@ -5,7 +5,7 @@ This file is generated from xml source: DO NOT EDIT XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX --> -<title>mod_headers - Apache HTTP Server</title> +<title>mod_headers - Apache HTTP Server Version 2.4</title> <link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /> <link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" /> <link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link rel="stylesheet" type="text/css" href="../style/css/prettify.css" /> @@ -89,7 +89,8 @@ RequestHeader unset MirrorID</pre> 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><Directory></code> or <code><Location></code>.</p> + <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> @@ -164,7 +165,7 @@ Header set MyHeader "%D %t mytext" env=HAVE_MyRequestHeader</pre> </li> <li> - Set the same header value under multiple non-exclusive conditions, + 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 @@ -194,6 +195,12 @@ Header merge Cache-Control no-store env=NO_STORE</pre> <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> @@ -201,14 +208,15 @@ Header merge Cache-Control no-store env=NO_STORE</pre> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configure HTTP response headers</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>Header [<var>condition</var>] add|append|echo|edit|edit*|merge|set|setifempty|unset|note -<var>header</var> [<var>value</var>] [<var>replacement</var>] -[early|env=[!]<var>variable</var>]|expr=<var>expression</var>] +<var>header</var> [[expr=]<var>value</var> [<var>replacement</var>] +[early|env=[!]<var>varname</var>|expr=<var>expression</var>]] </code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_headers</td></tr> -<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Default condition was temporarily changed to "always" in 2.3.9 and 2.3.10. SetIfEmpty available since 2.4.7.</td></tr> +<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>SetIfEmpty available in 2.4.7 and later, expr=value +available in 2.4.10 and later</td></tr> </table> <p>This directive can replace, merge or remove HTTP response headers. The header is modified just after the content handler @@ -216,22 +224,22 @@ Header merge Cache-Control no-store env=NO_STORE</pre> modified.</p> <p> The optional <var>condition</var> argument determines which internal - table of responses headers this directive will operate against. Other - components of the server may have stored their response headers in either - the table that corresponds to <code>onsuccess</code> or the table that - corresponds to <code>always</code>. "Always" in this context refers to - whether headers you add will be sent during both a successful and unsucessful - response, but if your action is a function of an existing header, you - will have to read on for further complications.</p> - - <p> The default value of <code>onsuccess</code> may need to be changed to - <code>always</code> under the circumstances similar to those listed below. + table of responses headers this directive will operate against. Despite the + name, the default value of <code>onsuccess</code> does <em>not</em> limit + an <var>action</var> to responses with a 2xx status code. Headers set under + this condition are still used when, for example, a request is <em>successfully</em> + proxied or generated by CGI, even when they have generated a failing status code.</p> + + <p>When your action is a function of an existing header, you may need to specify + a condition of <code>always</code>, depending on which internal table the + original header was set in. The table that corresponds to <code>always</code> is + used for locally generated error responses as well as successful responses. Note also that repeating this directive with both conditions makes sense in some scenarios because <code>always</code> is not a superset of <code>onsuccess</code> with respect to existing headers:</p> <ul> - <li> You're adding a header to a non-success (non-2xx) response, such + <li> You're adding a header to a locally generated non-success (non-2xx) response, such as a redirect, in which case only the table corresponding to <code>always</code> is used in the ultimate response.</li> <li> You're modifying or removing a header generated by a CGI script, @@ -242,6 +250,10 @@ Header merge Cache-Control no-store env=NO_STORE</pre> <code>onsuccess</code> condition.</li> </ul> + <p>Separately from the <var>condition</var> parameter described above, you + can limit an action based on HTTP status codes for e.g. proxied or CGI + requests. See the example that uses %{REQUEST_STATUS} in the section above.</p> + <p>The action it performs is determined by the first argument (second argument if a <var>condition</var> is specified). This can be one of the following values:</p> @@ -293,7 +305,8 @@ Header merge Cache-Control no-store env=NO_STORE</pre> <dt><code>setifempty</code></dt> <dd>The request header is set, but only if there is no previous header - with this name. Available in 2.4.7 and later.</dd> + with this name.<br /> + Available in 2.4.7 and later.</dd> <dt><code>unset</code></dt> <dd>The response header of this name is removed, if it exists. @@ -304,7 +317,8 @@ Header merge Cache-Control no-store env=NO_STORE</pre> <dd>The value of the named response <var>header</var> is copied into an internal note whose name is given by <var>value</var>. This is useful if a header sent by a CGI or proxied resource is configured to be unset - but should also be logged.</dd> + but should also be logged.<br /> + Available in 2.4.7 and later.</dd> </dl> @@ -320,9 +334,12 @@ Header merge Cache-Control no-store env=NO_STORE</pre> <code>add</code> a <var>value</var> is specified as the next argument. If <var>value</var> contains spaces, it should be surrounded by double quotes. - <var>value</var> may be a character string, a string containing format - specifiers or a combination of both. The following format specifiers - are supported in <var>value</var>:</p> + <var>value</var> may be a character string, a string containing + <code class="module"><a href="../mod/mod_headers.html">mod_headers</a></code> specific format specifiers (and character + literals), or an <a href="../expr.html">ap_expr</a> expression prefixed + with <em>expr=</em></p> + + <p> The following format specifiers are supported in <var>value</var>:</p> <table class="bordered"><tr class="header"><th>Format</th><th>Description</th></tr> <tr><td><code>%%</code></td> @@ -341,15 +358,18 @@ Header merge Cache-Control no-store env=NO_STORE</pre> designed to expose the values obtained by <code>getloadavg()</code> and this represents the current load average, the 5 minute average, and the 15 minute average. The value is preceded by <code>l=</code> with each - average separated by <code>/</code>. + average separated by <code>/</code>.<br /> + Available in 2.4.4 and later. </td></tr> <tr><td><code>%i</code></td> <td>The current idle percentage of httpd (0 to 100) based on available - processes and threads. The value is preceded by <code>i=</code>. + processes and threads. The value is preceded by <code>i=</code>.<br /> + Available in 2.4.4 and later. </td></tr> <tr class="odd"><td><code>%b</code></td> <td>The current busy percentage of httpd (0 to 100) based on available - processes and threads. The value is preceded by <code>b=</code>. + processes and threads. The value is preceded by <code>b=</code>.<br /> + Available in 2.4.4 and later. </td></tr> <tr><td><code>%{VARNAME}e</code></td> <td>The contents of the <a href="../env.html">environment @@ -390,9 +410,11 @@ Header merge Cache-Control no-store env=NO_STORE</pre> <p>Except in <a href="#early">early</a> mode, the <code class="directive">Header</code> directives are processed just - before the response is sent to the network. These means that it is - possible to set and/or override most headers, except for those headers - added by the HTTP header filter, such as Content-Type.</p> + before the response is sent to the network. This means that it is + possible to set and/or override most headers, except for some headers + added by the HTTP header filter. Prior to 2.2.12, it was not possible + to change the Content-Type header with this directive.</p> + </div> <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div> @@ -400,14 +422,15 @@ Header merge Cache-Control no-store env=NO_STORE</pre> <table class="directive"> <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configure HTTP request headers</td></tr> <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>RequestHeader add|append|edit|edit*|merge|set|setifempty|unset -<var>header</var> [<var>value</var>] [<var>replacement</var>] -[early|env=[!]<var>variable</var>]|expr=<var>expression</var>] +<var>header</var> [[expr=]<var>value</var> [<var>replacement</var>] +[early|env=[!]<var>varname</var>|expr=<var>expression</var>]] </code></td></tr> <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory, .htaccess</td></tr> <tr><th><a href="directive-dict.html#Override">Override:</a></th><td>FileInfo</td></tr> <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr> <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_headers</td></tr> -<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>SetIfEmpty available in 2.4.7 and later</td></tr> +<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>SetIfEmpty available in 2.4.7 and later, expr=value +available in 2.4.10 and later</td></tr> </table> <p>This directive can replace, merge, change or remove HTTP request headers. The header is modified just before the content handler @@ -458,7 +481,8 @@ Header merge Cache-Control no-store env=NO_STORE</pre> <dt><code>setifempty</code></dt> <dd>The request header is set, but only if there is no previous header - with this name. Available in 2.4.7 and later.</dd> + with this name.<br /> + Available in 2.4.7 and later.</dd> <dt><code>unset</code></dt> <dd>The request header of this name is removed, if it exists. If |