Regex stuff that was in 2.2 but not in trunk

<li><img alt="" src="../images/down.gif" /> <a href="#htaccess">.htaccess files</a></li>

<li><img alt="" src="../images/down.gif" /> <a href="#EnvVar">Environment Variables</a></li>

</ul><h3>See also</h3><ul class="seealso"><li><a href="../mod/mod_rewrite.html">Module

documentation</a></li><li><a href="rewrite_tech.html">Technical details</a></li><li><a href="rewrite_guide.html">Rewrite Guide - useful examples</a></li><li><a href="rewrite_guide_advanced.html">Advanced Rewrite Guide -

advanced useful examples</a></li></ul></div>

documentation</a></li><li><a href="rewrite_tech.html">Technical details</a></li><li><a href="rewrite_guide.html">Practical solutions to common

problems</a></li><li><a href="rewrite_guide_advanced.html">Practical solutions to

advanced problems</a></li></ul></div>

<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>

<div class="section">

<h2><a name="introduction" id="introduction">Introduction</a></h2>

<h3><a name="regexvocab" id="regexvocab">Regex vocabulary</a></h3>

<p>The following are the minimal building blocks you will need, in order

to write regular expressions and <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code>s.</p>

to write regular expressions and <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code>s. They certainly do not

represent a complete regular expression vocabulary, but they are a good

place to start, and should help you read basic regular expressions, as

well as write your own.</p>

<table>

<tr>

<th>Character</th>

<th>Meaning</th>

<th>Example</th>

</tr>

<tr><td><code>.</code></td><td>Matches any character</td></tr>

<tr><td><code>.</code></td><td>Matches any

character</td><td><code>c.t</code> will match <code>cat</code>,

<code>cot</code>, <code>cut</code>, etc.</td></tr>

<tr><td><code>+</code></td><td>Repeats the previous match one or more

times</td><td><code>a+</code> matches <code>a</code>, <code>aa</code>, 

<code>aaa</code>, etc</td></tr>

<tr><td><code>*</code></td><td>Repeats the previous match zero or more

times.</td><td><code>a*</code> matches all the same things

<code>a+</code> matches, but will also match an empty string.</td></tr>

<tr><td><code>?</code></td><td>Makes the match optional.</td><td /></tr>

<tr><td><code>.</code></td><td>Matches any

character</td><td><code>colou?r</code> will match <code>color</code> and

<code>colour</code>.</td></tr>

<tr><td><code>^</code></td><td>Called an anchor, matches the beginning

of the string</td><td><code>^a</code> matches a string that begins with

<code>a</code></td></tr>

<tr><td><code>$</code></td><td>The other anchor, this matches the end of

the string.</td><td><code>a$</code> matches a string that ends with

<code>a</code>.</td></tr>

<tr><td><code>( )</code></td><td>Groups several characters into a single

unit, and captures a match for use in a backreference.</td><td><code>(ab)+</code> 

matches <code>ababab</code> - that is, the <code>+</code> applies to the group.

For more on backreferences see <a href="#InternalBackRefs">below</a>.</td></tr>

<tr><td><code>[ ]</code></td><td>A character class - matches one of the

characters</td><td><code>c[uoa]t</code> matches <code>cut</code>,

<code>cot</code> or <code>cat</code>.</td></tr>

<tr><td><code>!</code></td><td>Not</td><td>Negates a match - that is,

ensures that it does not match.</td></tr>

</table>

<seealso><a href="../mod/mod_rewrite.html">Module

documentation</a></seealso>

<seealso><a href="rewrite_tech.html">Technical details</a></seealso>

<seealso><a href="rewrite_guide.html">Rewrite Guide - useful examples</a></seealso>

<seealso><a href="rewrite_guide_advanced.html">Advanced Rewrite Guide -

advanced useful examples</a></seealso>

<seealso><a href="rewrite_guide.html">Practical solutions to common

problems</a></seealso>

<seealso><a href="rewrite_guide_advanced.html">Practical solutions to

advanced problems</a></seealso>

<section id="introduction"><title>Introduction</title>

<p>The Apache module <module>mod_rewrite</module> is a very powerful and

<p>The following are the minimal building blocks you will need, in order

to write regular expressions and <directive

module="mod_rewrite">RewriteRule</directive>s.</p>

module="mod_rewrite">RewriteRule</directive>s. They certainly do not

represent a complete regular expression vocabulary, but they are a good

place to start, and should help you read basic regular expressions, as

well as write your own.</p>

<table>

<tr>

<th>Character</th>

<th>Meaning</th>

<th>Example</th>

</tr>

<tr><td><code>.</code></td><td>Matches any character</td></tr>

<tr><td><code>.</code></td><td>Matches any

character</td><td><code>c.t</code> will match <code>cat</code>,

<code>cot</code>, <code>cut</code>, etc.</td></tr>

<tr><td><code>+</code></td><td>Repeats the previous match one or more

times</td><td><code>a+</code> matches <code>a</code>, <code>aa</code>, 

<code>aaa</code>, etc</td></tr>

<tr><td><code>*</code></td><td>Repeats the previous match zero or more

times.</td><td><code>a*</code> matches all the same things

<code>a+</code> matches, but will also match an empty string.</td></tr>

<tr><td><code>?</code></td><td>Makes the match optional.</td><td></td></tr>

<tr><td><code>.</code></td><td>Matches any

character</td><td><code>colou?r</code> will match <code>color</code> and

<code>colour</code>.</td></tr>

<tr><td><code>^</code></td><td>Called an anchor, matches the beginning

of the string</td><td><code>^a</code> matches a string that begins with

<code>a</code></td></tr>

<tr><td><code>$</code></td><td>The other anchor, this matches the end of

the string.</td><td><code>a$</code> matches a string that ends with

<code>a</code>.</td></tr>

<tr><td><code>( )</code></td><td>Groups several characters into a single

unit, and captures a match for use in a backreference.</td><td><code>(ab)+</code> 

matches <code>ababab</code> - that is, the <code>+</code> applies to the group.

For more on backreferences see <a href="#InternalBackRefs">below</a>.</td></tr>

<tr><td><code>[ ]</code></td><td>A character class - matches one of the

characters</td><td><code>c[uoa]t</code> matches <code>cut</code>,

<code>cot</code> or <code>cat</code>.</td></tr>

<tr><td><code>!</code></td><td>Not</td><td>Negates a match - that is,

ensures that it does not match.</td></tr>

</table>