On regular expressions in VCL

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@5642 d4fa192b-c00b-0410-8231-f00ffab90ce4

doc/sphinx/index.rst

@@ -8,8 +8,9 @@ Varnish is a state of the art web accelerator. Its mission is to sit
 in front of a web server an cache the content. It makes your web site
 go fast.
 
-We suggest you start by reading the :ref:`install-index`. Once you
-have Varnish up and running go through the :ref:`tutorial-index`.
+We suggest you start by reading the installation guide
+:ref:`install-index`. Once you have Varnish up and running go through
+our tutorial - :ref:`tutorial-index`.
 
 
 Contents:

doc/sphinx/reference/vcl.rst

@@ -288,6 +288,22 @@ To match an IP address against an ACL, simply use the match operator:::
     return (pipe);
   }
 
+Regular Expressions
+-------------------
+
+In Varnish 2.1.0 Varnish switched to using PCRE - Perl-compatible
+regular expressions. For a complete description of PCRE please see the
+PCRE(3) man page.
+
+To send flags to the PCRE engine, such as to turn on *case
+insensitivity* add the flag within parens following a question mark,
+like this:::
+
+  if (req.http.host ~ "(?i)example.com$") {
+          ...
+  }
+
+
 Functions
 ---------