A little refactoring of the mod_setenvif docs. In particular, consolidate the

<status>Base</status>

<sourcefile>mod_setenvif.c</sourcefile>

<identifier>setenvif_module</identifier>

<compatibility>Available in Apache 1.3 and later</compatibility>

<summary>

<name>BrowserMatch</name>

<description>Sets environment variables conditional on HTTP User-Agent

</description>

<syntax>BrowserMatch <em>regex env-variable</em>[=<em>value</em>]

[<em>env-variable</em>[=<em>value</em>]] ...</syntax>

<syntax>BrowserMatch <em>regex [!]env-variable</em>[=<em>value</em>]

[[!]<em>env-variable</em>[=<em>value</em>]] ...</syntax>

<contextlist><context>server config</context>

<context>virtual host</context><context>directory</context>

<context>.htaccess</context></contextlist>

<override>FileInfo</override>

<compatibility>Apache 1.2 and

    above (in Apache 1.2 this directive was found in the

    now-obsolete mod_browser module)</compatibility>

<usage>

    <p>The <directive>BrowserMatch</directive> directive defines

    environment variables based on the <code>User-Agent</code> HTTP

    request header field.  The first argument should be a POSIX.2

    extended regular expression (similar to an

    <code>egrep</code>-style regex). The rest of the arguments give

    the names of variables to set, and optionally values to which they

    should be set. These take the form of</p>

    <ol>

      <li><code><em>varname</em></code>, or</li>

      <li><code>!<em>varname</em></code>, or</li>

      <li><code><em>varname</em>=<em>value</em></code></li>

    </ol>

    <p>In the first form, the value will be set to "1". The second

    will remove the given variable if already defined, and the

    third will set the variable to the value given by

    <code><em>value</em></code>. If a <code>User-Agent</code>

    string matches more than one entry, they will be merged.

    Entries are processed in the order in which they appear, and

    later entries can override earlier ones.</p>

  <p>The <directive>BrowserMatch</directive> is a special cases of the

  <directive module="mod_setenvif">SetEnvIf</directive> directive that

  sets environment variables conditional on the

  <code>User-Agent</code> HTTP request header.  The following two

  lines have the same effect:</p>

<example>

   BrowserMatchNoCase Robot is_a_robot<br /> 

   SetEnvIfNoCase User-Agent Robot is_a_robot<br /> 

</example>

    <p>For example:</p>

    <p>Some additional examples:</p>

<example>

    BrowserMatch ^Mozilla forms jpeg=yes browser=netscape<br />

    BrowserMatch "^Mozilla/[2-3]" tables agif frames javascript<br />

    BrowserMatch MSIE !javascript<br />

</example>

    <p>Note that the regular expression string is

    <strong>case-sensitive</strong>. For case-INsensitive matching,

    see the <directive

    module="mod_setenvif">BrowserMatchNoCase</directive>

    directive.</p>

    <p>The <directive>BrowserMatch</directive> and

    <directive>BrowserMatchNoCase</directive> directives are special cases of

    the <directive module="mod_setenvif">SetEnvIf</directive> and <directive

    module="mod_setenvif">SetEnvIfNoCase</directive>

    directives. The following two lines have the same effect:</p>

<example>

   BrowserMatchNoCase Robot is_a_robot<br />

   SetEnvIfNoCase User-Agent Robot is_a_robot<br />

</example>

</usage>

</directivesynopsis>

<name>BrowserMatchNoCase</name>

<description>Sets environment variables conditional on User-Agent without

respect to case</description>

<syntax>BrowserMatchNoCase  <em>regex env-variable</em>[=<em>value</em>]

    [<em>env-variable</em>[=<em>value</em>]] ...</syntax>

<syntax>BrowserMatchNoCase  <em>regex [!]env-variable</em>[=<em>value</em>]

    [[!]<em>env-variable</em>[=<em>value</em>]] ...</syntax>

<contextlist><context>server config</context>

<context>virtual host</context><context>directory</context>

<context>.htaccess</context></contextlist>

<description>Sets environment variables based on attributes of the request

</description>

<syntax>SetEnvIf <em>attribute

    regex env-variable</em>[=<em>value</em>]

    [<em>env-variable</em>[=<em>value</em>]] ...</syntax>

    regex [!]env-variable</em>[=<em>value</em>]

    [[!]<em>env-variable</em>[=<em>value</em>]] ...</syntax>

<contextlist><context>server config</context>

<context>virtual host</context><context>directory</context>

<context>.htaccess</context></contextlist>

<override>FileInfo</override>

<compatibility>Apache 1.3 and

    above; the Request_Protocol keyword and environment-variable

    matching are only available with 1.3.7 and later</compatibility>

<usage>

    <p>The <directive>SetEnvIf</directive> directive defines environment

    variables based on attributes of the request. These attributes

    can be the values of various HTTP request header fields (see <a

    <p>The <directive>SetEnvIf</directive> directive defines

    environment variables based on attributes of the request. The

    <em>attribute</em> specified in the first argument can be one of three

    things:</p>

<ol>

<li>An HTTP request header field (see <a

    href="http://www.rfc-editor.org/rfc/rfc2616.txt">RFC2616</a>

    for more information about these), or of other aspects of the

    request, including the following:</p>

    for more information about these); for example: <code>Host</code>,

    <code>User-Agent</code>, <code>Referer</code>, and 

    <code>Accept-Language</code>.  A regular expression may be

    used to specify a set of request headers.</li>

<li>One of the following aspects of the request:

    <ul>

      <li><code>Remote_Host</code> - the hostname (if available) of

      the client making the request</li>

      the protocol with which the request was made (<em>e.g.</em>,

      "HTTP/0.9", "HTTP/1.1", <em>etc.</em>)</li>

      <li><code>Request_URI</code> - the portion of the URL

      following the scheme and host portion</li>

      <li><code>Request_URI</code> - the resource requested on the HTTP

       request line -- generally the portion of the URL

      following the scheme and host portion without the query string</li>

    </ul>

</li>

<li>The name of an environment variable in the list of those

associated with the request. This allows

<directive>SetEnvIf</directive> directives to test against the result

of prior matches. Only those environment variables defined by earlier

<code>SetEnvIf[NoCase]</code> directives are available for testing in

this manner. 'Earlier' means that they were defined at a broader scope

(such as server-wide) or previously in the current directive's scope.

Environment variables will be considered only if there was no match

among request characteristics and a regular expression was not

used for the <em>attribute</em>.</li>

</ol>

<p>The second argument (<em>regex</em>) is a <a

href="http://www.pcre.org/">Perl compatible regular expression</a>.

This is similar to a POSIX.2 egrep-style regular expression.

If the <em>regex</em> matches against the <em>attribute</em>,

then the remainder of the arguments are evaluated.</p>

    <p>Some of the more commonly used request header field names

    include <code>Host</code>, <code>User-Agent</code>, and

    <code>Referer</code>.</p>

    <p>If the <em>attribute</em> name doesn't match any of the

    special keywords, nor any of the request's header field names,

    it is tested as the name of an environment variable in the list

    of those associated with the request. This allows

    <directive>SetEnvIf</directive> directives to test against the result of

    prior matches.</p>

<note>

      <strong>Only those environment variables defined by earlier

      <code>SetEnvIf[NoCase]</code> directives are available for

      testing in this manner. 'Earlier' means that they were

      defined at a broader scope (such as server-wide) or

      previously in the current directive's scope.</strong>

</note>

    <p><em>attribute</em> may be a regular expression when used to

    match a request header. If <em>attribute</em> is a regular

    expression and it doesn't match any of the request's header

    names, then <em>attribute</em> is not tested against the

    request's environment variable list.</p>

<p>The rest of the arguments give the names of variables to set, and

optionally values to which they should be set. These take the form

of</p>

    <ol>

      <li><code><em>varname</em></code>, or</li>

      <li><code>!<em>varname</em></code>, or</li>

      <li><code><em>varname</em>=<em>value</em></code></li>

    </ol>

    <p>In the first form, the value will be set to "1". The second

    will remove the given variable if already defined, and the

    third will set the variable to the literal value given by

    <code><em>value</em></code>.</p>

<example>

<title>Example:</title>

<name>SetEnvIfNoCase</name>

<description>Sets environment variables based on attributes of the request

without respect to case</description>

<syntax>SetEnvIfNoCase <em>attribute regex env-variable</em>[=<em>value</em>]

    [<em>env-variable</em>[=<em>value</em>]] ...</syntax>

<syntax>SetEnvIfNoCase <em>attribute regex 

        [!]env-variable</em>[=<em>value</em>]

    [[!]<em>env-variable</em>[=<em>value</em>]] ...</syntax>

<contextlist><context>server config</context>

<context>virtual host</context><context>directory</context>

<context>.htaccess</context></contextlist>