pre-translation improvements

        <title>Conditional Per-Request Settings</title>

        <p>For additional flexibility, the directives provided by

        mod_setenvif allow environment variables to be set on a

        per-request basis, conditional on characteristics of particular

        <module>mod_setenvif</module> allow environment variables to be set

        on a per-request basis, conditional on characteristics of particular

        requests. For example, a variable could be set only when a

        specific browser (User-Agent) is making a request, or only when

        a specific Referer [sic] header is found. Even more flexibility

        is available through the mod_rewrite's <directive 

        is available through the <module>mod_rewrite</module>'s <directive

        module="mod_rewrite">RewriteRule</directive> which uses the

        <code>[E=...]</code> option to set environment variables.</p>

    <section id="unique-identifiers">

        <title>Unique Identifiers</title>

        <p>Finally, mod_unique_id sets the environment variable

        <code>UNIQUE_ID</code> for each request to a value which is

        <p>Finally, <module>mod_unique_id</module> sets the environment variable <code>UNIQUE_ID</code> for each request to a value which is

        guaranteed to be unique across "all" requests under very

        specific conditions.</p>

    <section id="ssi-pages">

        <title>SSI Pages</title>

        <p>Server-parsed (SSI) documents processed by mod_include's

        <p>Server-parsed (SSI) documents processed by <module>mod_include</module>'s

        <code>INCLUDES</code> filter can print environment variables

        using the <code>echo</code> element, and can use environment

        variables in flow control elements to makes parts of a page

    <section id="url-rewriting">

        <title>URL Rewriting</title>

        <p>The <code>%{ENV:...}</code> form of <em>TestString</em> in

        the <directive module="mod_rewrite">RewriteCond</directive>

        allows mod_rewrite's rewrite

        <p>The <code>%{ENV:<em>variable</em>}</code> form of

        <em>TestString</em> in the <directive module="mod_rewrite"

        >RewriteCond</directive> allows <module>mod_rewrite</module>'s rewrite

        engine to make decisions conditional on environment variables.

        Note that the variables accessible in mod_rewrite without the

        <code>ENV:</code> prefix are not actually environment

        variables. Rather, they are variables special to mod_rewrite

        which cannot be accessed from other modules.</p>

        Note that the variables accessible in <module>mod_rewrite</module>

        without the <code>ENV:</code> prefix are not actually environment

        variables. Rather, they are variables special to

        <module>mod_rewrite</module> which cannot be accessed from other

        modules.</p>

    </section>

  </section>

    <section id="gzip-only-text-html">

        <title>gzip-only-text/html</title>

        <p>When set to a value of "1", this variable disables the DEFLATE

        output filter provided by <module>mod_deflate</module> for

        content-types other than <code>text/html</code>.</p>

        <p>When set to a value of "1", this variable disables the

        <code>DEFLATE</code> output filter provided by

        <module>mod_deflate</module> for content-types other than

        <code>text/html</code>.</p>

    </section>

    <section id="no-gzip"><title>no-gzip</title>

    <section id="nokeepalive">

        <title>nokeepalive</title>

        <p>This disables <directive module="core">KeepAlive</directive> when set.</p>

        <p>This disables <directive module="core">KeepAlive</directive>

        when set.</p>

    </section>

    the client can't (or doesn't) automatically follow the redirection.

    Apache ordinarily labels this text according to the character set

    which it uses, which is ISO-8859-1.</p>

    <p> However, if the redirection is to a page that uses a different

    character set, some broken browser versions will try to use the

    character set from the redirection text rather than the actual page.

    This can result in Greek, for instance, being incorrectly rendered.</p>

    <p>Setting this environment variable causes Apache to omit the character

    set for the redirection text, and these broken browsers will then correctly

    use that of the destination page.</p>

        access log. It can be easily modified to prevent logging of

        particular directories, or to prevent logging of requests

        coming from particular hosts.</p>

    <example><pre>

SetEnvIf Request_URI \.gif image-request

SetEnvIf Request_URI \.jpg image-request

SetEnvIf Request_URI \.png image-request

CustomLog logs/access_log common env=!image-request</pre></example>

        <example>

          SetEnvIf Request_URI \.gif image-request<br />

          SetEnvIf Request_URI \.jpg image-request<br />

          SetEnvIf Request_URI \.png image-request<br />

          CustomLog logs/access_log common env=!image-request

        </example>

    </section>

    <section id="image-theft">

        pages. This is not a recommended configuration, but it can work

        in limited circumstances. We assume that all your images are in

        a directory called /web/images.</p>

    <example><pre>

SetEnvIf Referer "^http://www.example.com/" local_referal

        <example>

          SetEnvIf Referer "^http://www\.example\.com/" local_referal

          # Allow browsers that do not send Referer info

          SetEnvIf Referer "^$" local_referal

          <Directory /web/images>

   Order Deny,Allow

   Deny from all

          <indent>

            Order Deny,Allow<br />

            Deny from all<br />

            Allow from env=local_referal

&lt;/Directory&gt;</pre></example>

          </indent>

          </Directory>

        </example>

        <p>For more information about this technique, see the

        ApacheToday tutorial " <a

        href="http://apachetoday.com/news_story.php3?ltsn=2000-06-14-002-01-PS">

    Keeping Your Images from Adorning Other Sites</a>".</p>

  "<a href="http://www.serverwatch.com/tutorials/article.php/1132731"

  >Keeping Your Images from Adorning Other Sites</a>" tutorial on

  ServerWatch.</p>

    </section>

  </section>

</manualpage>