mod_rewrite.html.en

linux服务器 源码。。。。。。。。。。。。。。

            compares it lexically to <em>TestString</em>. True if
            <em>TestString</em> is lexically equal to
            <em>CondPattern</em>, i.e the two strings are exactly
            equal (character by character). If <em>CondPattern</em>
            is just <samp>""</samp> (two quotation marks) this
            compares <em>TestString</em> to the empty string.</li>

            <li>'<strong>-d</strong>' (is
            <strong>d</strong>irectory)<br />
             Treats the <em>TestString</em> as a pathname and tests
            if it exists and is a directory.</li>

            <li>'<strong>-f</strong>' (is regular
            <strong>f</strong>ile)<br />
             Treats the <em>TestString</em> as a pathname and tests
            if it exists and is a regular file.</li>

            <li>'<strong>-s</strong>' (is regular file with
            <strong>s</strong>ize)<br />
             Treats the <em>TestString</em> as a pathname and tests
            if it exists and is a regular file with size greater
            than zero.</li>

            <li>'<strong>-l</strong>' (is symbolic
            <strong>l</strong>ink)<br />
             Treats the <em>TestString</em> as a pathname and tests
            if it exists and is a symbolic link.</li>

            <li>'<strong>-F</strong>' (is existing file via
            subrequest)<br />
             Checks if <em>TestString</em> is a valid file and
            accessible via all the server's currently-configured
            access controls for that path. This uses an internal
            subrequest to determine the check, so use it with care
            because it decreases your servers performance!</li>

            <li>'<strong>-U</strong>' (is existing URL via
            subrequest)<br />
             Checks if <em>TestString</em> is a valid URL and
            accessible via all the server's currently-configured
            access controls for that path. This uses an internal
            subrequest to determine the check, so use it with care
            because it decreases your server's performance!</li>
          </ul>

          <table width="70%" border="0" bgcolor="#E0E0F0"
          cellspacing="0" cellpadding="10">
            <tr>
              <td><strong>Notice:</strong> All of these tests can
              also be prefixed by an exclamation mark ('!') to
              negate their meaning.</td>
            </tr>
          </table>
        </li>
      </ol>

      <p>Additionally you can set special flags for
      <em>CondPattern</em> by appending</p>

      <blockquote>
        <strong><code>[</code><em>flags</em><code>]</code></strong>
      </blockquote>
      as the third argument to the <code>RewriteCond</code>
      directive. <em>Flags</em> is a comma-separated list of the
      following flags: 

      <ul>
        <li>'<strong><code>nocase|NC</code></strong>'
        (<strong>n</strong>o <strong>c</strong>ase)<br />
         This makes the test case-insensitive, <em>i.e.</em>, there
        is no difference between 'A-Z' and 'a-z' both in the
        expanded <em>TestString</em> and the <em>CondPattern</em>.
        This flag is effective only for comparisons between
        <em>TestString</em> and <em>CondPattern</em>. It has no
        effect on filesystem and subrequest checks.</li>

        <li>
          '<strong><code>ornext|OR</code></strong>'
          (<strong>or</strong> next condition)<br />
           Use this to combine rule conditions with a local OR
          instead of the implicit AND. Typical example: 

          <blockquote>
<pre>
RewriteCond %{REMOTE_HOST}  ^host1.*  [OR]
RewriteCond %{REMOTE_HOST}  ^host2.*  [OR]
RewriteCond %{REMOTE_HOST}  ^host3.*
RewriteRule ...some special stuff for any of these hosts...
</pre>
          </blockquote>
          Without this flag you would have to write the cond/rule
          three times.
        </li>
      </ul>

      <p><strong>Example:</strong></p>

      <blockquote>
        To rewrite the Homepage of a site according to the
        ``<code>User-Agent:</code>'' header of the request, you can
        use the following: 

        <blockquote>
<pre>
RewriteCond  %{HTTP_USER_AGENT}  ^Mozilla.*
RewriteRule  ^/$                 /homepage.max.html  [L]

RewriteCond  %{HTTP_USER_AGENT}  ^Lynx.*
RewriteRule  ^/$                 /homepage.min.html  [L]

RewriteRule  ^/$                 /homepage.std.html  [L]
</pre>
        </blockquote>
        Interpretation: If you use Netscape Navigator as your
        browser (which identifies itself as 'Mozilla'), then you
        get the max homepage, which includes Frames, <em>etc.</em>
        If you use the Lynx browser (which is Terminal-based), then
        you get the min homepage, which contains no images, no
        tables, <em>etc.</em> If you use any other browser you get
        the standard homepage.
      </blockquote>
      <hr noshade="noshade" size="1" />

      <h3><a id="RewriteRule"
      name="RewriteRule">RewriteRule</a></h3>
      <a href="directive-dict.html#Syntax"
      rel="Help"><strong>Syntax:</strong></a> RewriteRule
      <em>Pattern</em> <em>Substitution</em><br />
       <a href="directive-dict.html#Default"
      rel="Help"><strong>Default:</strong></a> <em>None</em><br />
       <a href="directive-dict.html#Context"
      rel="Help"><strong>Context:</strong></a> server config,
      virtual host, directory, .htaccess<br />
       <a href="directive-dict.html#Override"
      rel="Help"><strong>Override:</strong></a>
      <em>FileInfo</em><br />
       <a href="directive-dict.html#Status"
      rel="Help"><strong>Status:</strong></a> Extension<br />
       <a href="directive-dict.html#Module"
      rel="Help"><strong>Module:</strong></a> mod_rewrite.c<br />
       <a href="directive-dict.html#Compatibility"
      rel="Help"><strong>Compatibility:</strong></a> Apache 1.2
      (partially), Apache 1.3<br />
       

      <p>The <code>RewriteRule</code> directive is the real
      rewriting workhorse. The directive can occur more than once.
      Each directive then defines one single rewriting rule. The
      <strong>definition order</strong> of these rules is
      <strong>important</strong>, because this order is used when
      applying the rules at run-time.</p>

      <p><a id="patterns" name="patterns"><em>Pattern</em></a> can
      be (for Apache 1.1.x a System V8 and for Apache 1.2.x and
      later a POSIX) <a id="regexp" name="regexp">regular
      expression</a> which gets applied to the current URL. Here
      ``current'' means the value of the URL when this rule gets
      applied. This may not be the originally requested URL,
      because any number of rules may already
      have matched and made alterations to it.</p>

      <p>Some hints about the syntax of regular expressions:</p>

      <table bgcolor="#F0F0F0" cellspacing="0" cellpadding="5">
        <tr>
          <td valign="TOP">
<pre>
<strong>Text:</strong>
  <strong><code>.</code></strong>           Any single character
  <strong><code>[</code></strong>chars<strong><code>]</code></strong>     Character class: One  of chars
  <strong><code>[^</code></strong>chars<strong><code>]</code></strong>    Character class: None of chars
  text1<strong><code>|</code></strong>text2 Alternative: text1 or text2

<strong>Quantifiers:</strong>
  <strong><code>?</code></strong>           0 or 1 of the preceding text
  <strong><code>*</code></strong>           0 or N of the preceding text (N &gt; 0)
  <strong><code>+</code></strong>           1 or N of the preceding text (N &gt; 1)

<strong>Grouping:</strong>
  <strong><code>(</code></strong>text<strong><code>)</code></strong>      Grouping of text
              (either to set the borders of an alternative or
              for making backreferences where the <strong>N</strong>th group can 
              be used on the RHS of a RewriteRule with <code>$</code><strong>N</strong>)

<strong>Anchors:</strong>
  <strong><code>^</code></strong>           Start of line anchor
  <strong><code>$</code></strong>           End   of line anchor

<strong>Escaping:</strong>
  <strong><code>\</code></strong>char       escape that particular char
              (for instance to specify the chars "<code>.[]()</code>" <em>etc.</em>)
</pre>
          </td>
        </tr>
      </table>

      <p>For more information about regular expressions either have
      a look at your local regex(3) manpage or its
      <code>src/regex/regex.3</code> copy in the Apache 1.3
      distribution. If you are interested in more detailed
      information about regular expressions and their variants
      (POSIX regex, Perl regex, <em>etc.</em>) have a look at the
      following dedicated book on this topic:</p>

      <blockquote>
        <em>Mastering Regular Expressions</em><br />
         Jeffrey E.F. Friedl<br />
         Nutshell Handbook Series<br />
         O'Reilly &amp; Associates, Inc. 1997<br />
         ISBN 1-56592-257-3<br />
      </blockquote>

      <p>Additionally in mod_rewrite the NOT character
      ('<code>!</code>') is a possible pattern prefix. This gives
      you the ability to negate a pattern; to say, for instance:
      ``<em>if the current URL does <strong>NOT</strong> match this
      pattern</em>''. This can be used for exceptional cases, where
      it is easier to match the negative pattern, or as a last
      default rule.</p>

      <table width="70%" border="0" bgcolor="#E0E0F0"
      cellspacing="0" cellpadding="10">
        <tr>
          <td><strong>Notice:</strong> When using the NOT character
          to negate a pattern you cannot have grouped wildcard
          parts in the pattern. This is impossible because when the
          pattern does NOT match, there are no contents for the
          groups. In consequence, if negated patterns are used, you
          cannot use <code>$N</code> in the substitution
          string!</td>
        </tr>
      </table>

      <p><a id="rhs" name="rhs"><em>Substitution</em></a> of a
      rewriting rule is the string which is substituted for (or
      replaces) the original URL for which <em>Pattern</em>
      matched. Beside plain text you can use</p>

      <ol>
        <li>back-references <code>$N</code> to the RewriteRule
        pattern</li>

        <li>back-references <code>%N</code> to the last matched
        RewriteCond pattern</li>

        <li>server-variables as in rule condition test-strings
        (<code>%{VARNAME}</code>)</li>

        <li><a href="#mapfunc">mapping-function</a> calls
        (<code>${mapname:key|default}</code>)</li>
      </ol>
      Back-references are <code>$</code><strong>N</strong>
      (<strong>N</strong>=0..9) identifiers which will be replaced
      by the contents of the <strong>N</strong>th group of the
      matched <em>Pattern</em>. The server-variables are the same
      as for the <em>TestString</em> of a <code>RewriteCond</code>
      directive. The mapping-functions come from the
      <code>RewriteMap</code> directive and are explained there.
      These three types of variables are expanded in the order of
      the above list. 

      <p>As already mentioned above, all the rewriting rules are
      applied to the <em>Substitution</em> (in the order of
      definition in the config file). The URL is <strong>completely
      replaced</strong> by the <em>Substitution</em> and the
      rewriting process goes on until there are no more rules
      unless explicitly terminated by a
      <code><strong>L</strong></code> flag - see below.</p>

      <p>There is a special substitution string named
      '<code>-</code>' which means: <strong>NO
      substitution</strong>! Sounds silly? No, it is useful to
      provide rewriting rules which <strong>only</strong> match
      some URLs but do no substitution, <em>e.g.</em>, in
      conjunction with the <strong>C</strong> (chain) flag to be
      able to have more than one pattern to be applied before a
      substitution occurs.</p>

      <p>One more note: You can even create URLs in the
      substitution string containing a query string part. Just use
      a question mark inside the substitution string to indicate
      that the following stuff should be re-injected into the
      QUERY_STRING. When you want to erase an existing query
      string, end the substitution string with just the question
      mark.</p>

      <table width="70%" border="0" bgcolor="#E0E0F0"
      cellspacing="0" cellpadding="10">
        <tr>
          <td><strong>Note</strong>: There is a special feature:
          When you prefix a substitution field with
          <code>http://</code><em>thishost</em>[<em>:thisport</em>]
          then <strong>mod_rewrite</strong> automatically strips it
          out. This auto-reduction on implicit external redirect
          URLs is a useful and important feature when used in
          combination with a mapping-function which generates the
          hostname part. Have a look at the first example in the
          example section below to understand this.</td>
        </tr>
      </table>

      <table width="70%" border="0" bgcolor="#E0E0F0"
      cellspacing="0" cellpadding="10">
        <tr>
          <td><strong>Remember:</strong> An unconditional external
          redirect to your own server will not work with the prefix
          <code>http://thishost</code> because of this feature. To
          achieve such a self-redirect, you have to use the
          <strong>R</strong>-flag (see below).</td>
        </tr>
      </table>

      <p>Additionally you can set special flags for
      <em>Substitution</em> by appending</p>

      <blockquote>
        <strong><code>[</code><em>flags</em><code>]</code></strong>
      </blockquote>
      as the third argument to the <code>RewriteRule</code>
      directive. <em>Flags</em> is a comma-separated list of the
      following flags: 

      <ul>
        <li>
          '<strong><code>redirect|R</code>
          [=<em>code</em>]</strong>' (force <a id="redirect"
          name="redirect"><strong>r</strong>edirect</a>)<br />
           Prefix <em>Substitution</em> with