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最新apache的源代码

      <Directory "/path-to-nfs-files">
      <span class="indent">
        EnableSendfile Off
      </span>
      &lt;/Directory&gt;
    </code></p></div>

</div>
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<div class="directive-section"><h2><a name="ErrorDocument" id="ErrorDocument">ErrorDocument</a> <a name="errordocument" id="errordocument">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>What the server will return to the client
in case of an error</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ErrorDocument <var>error-code</var> <var>document</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>Core</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Quoting syntax for text messages is different in Apache
2.0</td></tr>
</table>
    <p>In the event of a problem or error, Apache can be configured
    to do one of four things,</p>

    <ol>
      <li>output a simple hardcoded error message</li>

      <li>output a customized message</li>

      <li>redirect to a local <var>URL-path</var> to handle the
      problem/error</li>

      <li>redirect to an external <var>URL</var> to handle the
      problem/error</li>
    </ol>

    <p>The first option is the default, while options 2-4 are
    configured using the <code class="directive">ErrorDocument</code>
    directive, which is followed by the HTTP response code and a URL
    or a message. Apache will sometimes offer additional information
    regarding the problem/error.</p>

    <p>URLs can begin with a slash (/) for local web-paths (relative
    to the <code class="directive"><a href="#documentroot">DocumentRoot</a></code>), or be a
    full URL which the client can resolve. Alternatively, a message
    can be provided to be displayed by the browser. Examples:</p>

    <div class="example"><p><code>
      ErrorDocument 500 http://foo.example.com/cgi-bin/tester<br />
      ErrorDocument 404 /cgi-bin/bad_urls.pl<br />
      ErrorDocument 401 /subscription_info.html<br />
      ErrorDocument 403 "Sorry can't allow you access today"
    </code></p></div>

    <p>Additionally, the special value <code>default</code> can be used
    to specify Apache's simple hardcoded message.  While not required
    under normal circumstances, <code>default</code> will restore
    Apache's simple hardcoded message for configurations that would
    otherwise inherit an existing <code class="directive">ErrorDocument</code>.</p>

    <div class="example"><p><code>
      ErrorDocument 404 /cgi-bin/bad_urls.pl<br /><br />
      &lt;Directory /web/docs&gt;<br />
      <span class="indent">
        ErrorDocument 404 default<br />
      </span>
      &lt;/Directory&gt;
    </code></p></div>

    <p>Note that when you specify an <code class="directive">ErrorDocument</code>
    that points to a remote URL (ie. anything with a method such as
    <code>http</code> in front of it), Apache will send a redirect to the
    client to tell it where to find the document, even if the
    document ends up being on the same server. This has several
    implications, the most important being that the client will not
    receive the original error status code, but instead will
    receive a redirect status code. This in turn can confuse web
    robots and other clients which try to determine if a URL is
    valid using the status code. In addition, if you use a remote
    URL in an <code>ErrorDocument 401</code>, the client will not
    know to prompt the user for a password since it will not
    receive the 401 status code. Therefore, <strong>if you use an
    <code>ErrorDocument 401</code> directive then it must refer to a local
    document.</strong></p>

    <p>Microsoft Internet Explorer (MSIE) will by default ignore
    server-generated error messages when they are "too small" and substitute
    its own "friendly" error messages. The size threshold varies depending on
    the type of error, but in general, if you make your error document
    greater than 512 bytes, then MSIE will show the server-generated
    error rather than masking it.  More information is available in
    Microsoft Knowledge Base article <a href="http://support.microsoft.com/default.aspx?scid=kb;en-us;Q294807">Q294807</a>.</p>

    <p>Although most error messages can be overriden, there are certain
    circumstances where the internal messages are used regardless of the
    setting of <code class="directive"><a href="#errordocument">ErrorDocument</a></code>.  In
    particular, if a malformed request is detected, normal request processing
    will be immediately halted and the internal error message returned.
    This is necessary to guard against security problems caused by
    bad requests.</p>

    <p>Prior to version 2.0, messages were indicated by prefixing
    them with a single unmatched double quote character.</p>

<h3>See also</h3>
<ul>
<li><a href="../custom-error.html">documentation of
    customizable responses</a></li>
</ul>
</div>
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<div class="directive-section"><h2><a name="ErrorLog" id="ErrorLog">ErrorLog</a> <a name="errorlog" id="errorlog">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Location where the server will log errors</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code> ErrorLog <var>file-path</var>|syslog[:<var>facility</var>]</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ErrorLog logs/error_log (Unix) ErrorLog logs/error.log (Windows and OS/2)</code></td></tr>
<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
</table>
    <p>The <code class="directive">ErrorLog</code> directive sets the name of
    the file to which the server will log any errors it encounters. If
    the <var>file-path</var> is not absolute then it is assumed to be 
    relative to the <code class="directive"><a href="#serverroot">ServerRoot</a></code>.</p>

    <div class="example"><h3>Example</h3><p><code>
    ErrorLog /var/log/httpd/error_log
    </code></p></div>

    <p>If the <var>file-path</var>
    begins with a pipe (|) then it is assumed to be a command to spawn
    to handle the error log.</p>

    <div class="example"><h3>Example</h3><p><code>
    ErrorLog "|/usr/local/bin/httpd_errors"
    </code></p></div>

    <p>Using <code>syslog</code> instead of a filename enables logging
    via syslogd(8) if the system supports it. The default is to use
    syslog facility <code>local7</code>, but you can override this by
    using the <code>syslog:<var>facility</var></code> syntax where
    <var>facility</var> can be one of the names usually documented in
    syslog(1).</p>

    <div class="example"><h3>Example</h3><p><code>
    ErrorLog syslog:user
    </code></p></div>

    <p>SECURITY: See the <a href="../misc/security_tips.html#serverroot">security tips</a>
    document for details on why your security could be compromised
    if the directory where log files are stored is writable by
    anyone other than the user that starts the server.</p>
    <div class="warning"><h3>Note</h3>
      <p>When entering a file path on non-Unix platforms, care should be taken
      to make sure that only forward slashed are used even though the platform
      may allow the use of back slashes. In general it is a good idea to always 
      use forward slashes throughout the configuration files.</p>
    </div>

<h3>See also</h3>
<ul>
<li><code class="directive"><a href="#loglevel">LogLevel</a></code></li>
<li><a href="../logs.html">Apache Log Files</a></li>
</ul>
</div>
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<div class="directive-section"><h2><a name="FileETag" id="FileETag">FileETag</a> <a name="fileetag" id="fileetag">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>File attributes used to create the ETag
HTTP response header</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>FileETag <var>component</var> ...</code></td></tr>
<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>FileETag INode MTime Size</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>Core</td></tr>
<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>core</td></tr>
</table>
    <p>
    The <code class="directive">FileETag</code> directive configures the file
    attributes that are used to create the <code>ETag</code> (entity
    tag) response header field when the document is based on a file.
    (The <code>ETag</code> value is used in cache management to save
    network bandwidth.) In Apache 1.3.22 and earlier, the
    <code>ETag</code> value was <em>always</em> formed
    from the file's inode, size, and last-modified time (mtime). The
    <code class="directive">FileETag</code> directive allows you to choose
    which of these -- if any -- should be used. The recognized keywords are:
    </p>

    <dl>
     <dt><strong>INode</strong></dt>
     <dd>The file's i-node number will be included in the calculation</dd>
     <dt><strong>MTime</strong></dt>
     <dd>The date and time the file was last modified will be included</dd>
     <dt><strong>Size</strong></dt>
     <dd>The number of bytes in the file will be included</dd>
     <dt><strong>All</strong></dt>
     <dd>All available fields will be used. This is equivalent to:
         <div class="example"><p><code>FileETag INode MTime Size</code></p></div></dd>
     <dt><strong>None</strong></dt>
     <dd>If a document is file-based, no <code>ETag</code> field will be
       included in the response</dd>
    </dl>

    <p>The <code>INode</code>, <code>MTime</code>, and <code>Size</code>
    keywords may be prefixed with either <code>+</code> or <code>-</code>,
    which allow changes to be made to the default setting inherited
    from a broader scope. Any keyword appearing without such a prefix
    immediately and completely cancels the inherited setting.</p>

    <p>If a directory's configuration includes
    <code>FileETag&nbsp;INode&nbsp;MTime&nbsp;Size</code>, and a
    subdirectory's includes <code>FileETag&nbsp;-INode</code>,
    the setting for that subdirectory (which will be inherited by
    any sub-subdirectories that don't override it) will be equivalent to
    <code>FileETag&nbsp;MTime&nbsp;Size</code>.</p>

</div>
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<div class="directive-section"><h2><a name="Files" id="Files">&lt;Files&gt;</a> <a name="files" id="files">Directive</a></h2>
<table class="directive">
<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Contains directives that apply to matched
filenames</td></tr>
<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>&lt;Files <var>filename</var>&gt; ... &lt;/Files&gt;</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>All</td></tr>
<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Core</td><