<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Configure HTTP response headers also for error responses</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ErrorHeader set|append|add|unset|echo <var>header</var>
-[<var>value</var> [env=[!]<var>variable</var>]]</code></td></tr>
+[<var>value</var>] [env=[!]<var>variable</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>
<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 set|append|add|unset|echo <var>header</var>
-[<var>value</var> [env=[!]<var>variable</var>]]</code></td></tr>
+[<var>value</var>] [env=[!]<var>variable</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>
<dt><code>unset</code></dt>
<dd>The response header of this name is removed, if it exists.
If there are multiple headers of the same name, all will be
- removed.</dd>
+ removed. <var>value</var> must be omitted.</dd>
<dt><code>echo</code></dt>
<dd>Request headers with this name are echoed back in the
- response headers. <var>header</var> may be a regular expression.</dd>
+ response headers. <var>header</var> may be a regular expression.
+ <var>value</var> must be omitted.</dd>
</dl>
<p>This argument is followed by a <var>header</var> name, which
specifiers or a combination of both. The following format specifiers
are supported in <var>value</var>:</p>
- <table class="bordered">
-
- <tr><td><code>%t</code></td>
+ <table class="bordered"><tr class="header"><th>Format</th><th>Description</th></tr>
+<tr><td><code>%%</code></td>
+ <td>The percent sign</td></tr>
+<tr class="odd"><td><code>%t</code></td>
<td>The time the request was received in Universal Coordinated Time
since the epoch (Jan. 1, 1970) measured in microseconds. The value
is preceded by <code>t=</code>.</td></tr>
-
- <tr><td><code>%D</code></td>
+<tr><td><code>%D</code></td>
<td>The time from when the request was received to the time the
headers are sent on the wire. This is a measure of the duration
of the request. The value is preceded by <code>D=</code>.</td></tr>
-
- <tr><td><code>%{FOOBAR}e</code></td>
+<tr class="odd"><td><code>%{FOOBAR}e</code></td>
<td>The contents of the <a href="../env.html">environment
variable</a> <code>FOOBAR</code>.</td></tr>
-
- <tr><td><code>%{FOOBAR}s</code></td>
+<tr><td><code>%{FOOBAR}s</code></td>
<td>The contents of the <a href="mod_ssl.html#envvars">SSL environment
variable</a> <code>FOOBAR</code>, if <code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code> is enabled.</td></tr>
-
- </table>
+</table>
<div class="note"><h3>Note</h3>
-
<p>The <code>%s</code> format specifier is only available in
Apache 2.1 and later; it can be used instead of <code>%e</code>
to avoid the overhead of enabling <code>SSLOptions
+StdEnvVars</code>. If <code>SSLOptions +StdEnvVars</code> must
be enabled anyway for some other reason, <code>%e</code> will be
more efficient than <code>%s</code>.</p>
-
</div>
- <p>When the <code class="directive">Header</code> directive is used with the
- <code>add</code>, <code>append</code>, or <code>set</code>
- argument, a fourth argument may be used to specify conditions
+ <p>The <code class="directive">Header</code> directive may be followed by an
+ additional argument, which may be used to specify conditions
under which the action will be taken. If the <a href="../env.html">environment variable</a> specified in the
- <code>env=...</code> argument exists (or if the environment
- variable does not exist and <code>env=!...</code> is specified)
+ <code>env=<var>...</var></code> argument exists (or if the environment
+ variable does not exist and <code>env=!<var>...</var></code> is specified)
then the action specified by the <code class="directive">Header</code> directive
will take effect. Otherwise, the directive will have no effect
on the request.</p>
<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 set|append|add|unset <var>header</var>
-[<var>value</var> [env=[!]<var>variable</var>]]</code></td></tr>
+[<var>value</var>] [env=[!]<var>variable</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>
<dt><code>unset</code></dt>
<dd>The request header of this name is removed, if it exists. If
- there are multiple headers of the same name, all will be removed.</dd>
+ there are multiple headers of the same name, all will be removed.
+ <var>value</var> must be omitted.</dd>
</dl>
<p>This argument is followed by a header name, which can
ignored. For <code>add</code>, <code>append</code> and
<code>set</code> a <var>value</var> is given as the third argument. If
<var>value</var> contains spaces, it should be surrounded by double
- quotes. For unset, no <var>value</var> should be given.</p>
-
- <p>When the <code class="directive">RequestHeader</code> directive is used with the
- <code>add</code>, <code>append</code>, or <code>set</code> argument, a
- fourth argument may be used to specify conditions under which the action
- will be taken. If the <a href="../env.html">environment variable</a>
- specified in the <code>env=...</code> argument exists (or if the environment
- variable does not exist and <code>env=!...</code> is specified) then the
- action specified by the <code class="directive">RequestHeader</code> directive will
- take effect. Otherwise, the directive will have no effect on the
- request.</p>
+ quotes. For unset, no <var>value</var> should be given.
+ <var>value</var> may be a character string, a string containing format
+ specifiers or a combination of both. The supported format specifiers
+ are the same as for the <code class="directive"><a href="#header">Header</a></code>,
+ please have a look there for details.</p>
+
+ <p>The <code class="directive">RequestHeader</code> directive may be followed by
+ an additional argument, which may be used to specify conditions under
+ which the action will be taken. If the <a href="../env.html">environment
+ variable</a> specified in the <code>env=<var>...</var></code> argument
+ exists (or if the environment variable does not exist and
+ <code>env=!<var>...</var></code> is specified) then the action specified
+ by the <code class="directive">RequestHeader</code> directive will take effect.
+ Otherwise, the directive will have no effect on the request.</p>
<p>The <code class="directive">RequestHeader</code> directive is processed
just before the request is run by its handler in the fixup phase.
<tr class="odd"><td><a href="core.html#errordocument">ErrorDocument <var>Fehlercode</var> <var>Dokument</var></a></td><td></td><td>svdh</td><td>C</td></tr><tr class="odd"><td class="descr" colspan="4">Das, was der Server im Fehlerfall an den Client
zurückgibt</td></tr>
<tr><td><a href="mod_headers.html#errorheader">ErrorHeader set|append|add|unset|echo <var>header</var>
-[<var>value</var> [env=[!]<var>variable</var>]]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP response headers also for error responses</td></tr>
+[<var>value</var>] [env=[!]<var>variable</var>]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP response headers also for error responses</td></tr>
<tr class="odd"><td><a href="core.html#errorlog"> ErrorLog <var>Dateiname</var>|syslog[:<var>facility</var>]</a></td><td> logs/error_log (Uni +</td><td>sv</td><td>C</td></tr><tr class="odd"><td class="descr" colspan="4">Ablageort, an dem der Server Fehler protokolliert</td></tr>
<tr><td><a href="mod_example.html#example">Example</a></td><td></td><td>svdh</td><td>X</td></tr><tr><td class="descr" colspan="4">Demonstration directive to illustrate the Apache module
API</td></tr>
<tr class="odd"><td><a href="mpm_common.html#group" id="G" name="G">Group <var>Unix-Gruppe</var></a></td><td> #-1 </td><td>s</td><td>M</td></tr><tr class="odd"><td class="descr" colspan="4">Benutzergruppe, unter welcher der Server Anfragen
beantwortet</td></tr>
<tr><td><a href="mod_headers.html#header" id="H" name="H">Header set|append|add|unset|echo <var>header</var>
-[<var>value</var> [env=[!]<var>variable</var>]]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP response headers</td></tr>
+[<var>value</var>] [env=[!]<var>variable</var>]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP response headers</td></tr>
<tr class="odd"><td><a href="mod_autoindex.html#headername">HeaderName <var>filename</var></a></td><td></td><td>svdh</td><td>B</td></tr><tr class="odd"><td class="descr" colspan="4">Name of the file that will be inserted at the top
of the index listing</td></tr>
<tr><td><a href="core.html#hostnamelookups">HostnameLookups On|Off|Double</a></td><td> Off </td><td>svd</td><td>C</td></tr><tr><td class="descr" colspan="4">Aktiviert DNS-Lookups auf Client-IP-Adressen</td></tr>
...</a></td><td></td><td>vdh</td><td>B</td></tr><tr class="odd"><td class="descr" colspan="4">Removes any content type associations for a set of file
extensions</td></tr>
<tr><td><a href="mod_headers.html#requestheader">RequestHeader set|append|add|unset <var>header</var>
-[<var>value</var> [env=[!]<var>variable</var>]]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP request headers</td></tr>
+[<var>value</var>] [env=[!]<var>variable</var>]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP request headers</td></tr>
<tr class="odd"><td><a href="core.html#require">Require <var>Name</var> [<var>Name</var>] ...</a></td><td></td><td>dh</td><td>C</td></tr><tr class="odd"><td class="descr" colspan="4">Wählt die authentisierten Benutzer aus, die auf eine
Ressource zugreifen können</td></tr>
<tr><td><a href="mod_rewrite.html#rewritebase">RewriteBase <em>URL-path</em></a></td><td></td><td>dh</td><td>E</td></tr><tr><td class="descr" colspan="4">Sets the base URL for per-directory rewrites</td></tr>
<tr class="odd"><td><a href="core.html#errordocument">ErrorDocument <var>error-code</var> <var>document</var></a></td><td></td><td>svdh</td><td>C</td></tr><tr class="odd"><td class="descr" colspan="4">What the server will return to the client
in case of an error</td></tr>
<tr><td><a href="mod_headers.html#errorheader">ErrorHeader set|append|add|unset|echo <var>header</var>
-[<var>value</var> [env=[!]<var>variable</var>]]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP response headers also for error responses</td></tr>
+[<var>value</var>] [env=[!]<var>variable</var>]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP response headers also for error responses</td></tr>
<tr class="odd"><td><a href="core.html#errorlog"> ErrorLog <var>file-path</var>|syslog[:<var>facility</var>]</a></td><td> logs/error_log (Uni +</td><td>sv</td><td>C</td></tr><tr class="odd"><td class="descr" colspan="4">Location where the server will log errors</td></tr>
<tr><td><a href="mod_example.html#example">Example</a></td><td></td><td>svdh</td><td>X</td></tr><tr><td class="descr" colspan="4">Demonstration directive to illustrate the Apache module
API</td></tr>
<tr class="odd"><td><a href="mpm_common.html#group" id="G" name="G">Group <var>unix-group</var></a></td><td> #-1 </td><td>s</td><td>M</td></tr><tr class="odd"><td class="descr" colspan="4">Group under which the server will answer
requests</td></tr>
<tr><td><a href="mod_headers.html#header" id="H" name="H">Header set|append|add|unset|echo <var>header</var>
-[<var>value</var> [env=[!]<var>variable</var>]]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP response headers</td></tr>
+[<var>value</var>] [env=[!]<var>variable</var>]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP response headers</td></tr>
<tr class="odd"><td><a href="mod_autoindex.html#headername">HeaderName <var>filename</var></a></td><td></td><td>svdh</td><td>B</td></tr><tr class="odd"><td class="descr" colspan="4">Name of the file that will be inserted at the top
of the index listing</td></tr>
<tr><td><a href="core.html#hostnamelookups">HostnameLookups On|Off|Double</a></td><td> Off </td><td>svd</td><td>C</td></tr><tr><td class="descr" colspan="4">Enables DNS lookups on client IP addresses</td></tr>
...</a></td><td></td><td>vdh</td><td>B</td></tr><tr class="odd"><td class="descr" colspan="4">Removes any content type associations for a set of file
extensions</td></tr>
<tr><td><a href="mod_headers.html#requestheader">RequestHeader set|append|add|unset <var>header</var>
-[<var>value</var> [env=[!]<var>variable</var>]]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP request headers</td></tr>
+[<var>value</var>] [env=[!]<var>variable</var>]</a></td><td></td><td>svdh</td><td>E</td></tr><tr><td class="descr" colspan="4">Configure HTTP request headers</td></tr>
<tr class="odd"><td><a href="core.html#require">Require <var>entity-name</var> [<var>entity-name</var>] ...</a></td><td></td><td>dh</td><td>C</td></tr><tr class="odd"><td class="descr" colspan="4">Selects which authenticated users can access
a resource</td></tr>
<tr><td><a href="mod_rewrite.html#rewritebase">RewriteBase <em>URL-path</em></a></td><td></td><td>dh</td><td>E</td></tr><tr><td class="descr" colspan="4">Sets the base URL for per-directory rewrites</td></tr>