View source for HttpMapModule

== map ==
<include wikitext nopre src="http://wiki.nginx.org/nginx.org/http/ngx_http_map_module/map.txt" />

'''map''' defines the mapping table which will be used to set a variable.

The table has two columns, '''pattern''' and '''value'''.

Since 0.9.6, regular expressions can be used as patterns using a ~ prefix.

Since 1.0.4, case insensitive regular expressions can be used by prefixing the pattern with ~*.

<pre>
map $uri $myvalue {
    /aa                   /mapped_aa;
    ~^/aa/(?<suffix>.*)$  $suffix;
}
</pre>

If you need to have a tilde to start the pattern but not have it be a regular expression, the pattern can be prefixed with a backslash ('\'):

<pre>
map $http_referer $myvalue {
    Mozilla    1234;
    \~Mozilla  5678;
}
</pre>

There are three special parameters:

* default — defines the value to be used where no match is found.
* hostnames — it allows for an easier matching of values like host names, names with a starting dot may match exact host names and host names ending with the value, for example: 
<pre>
*.example.com  1; 
</pre> 

Instead of two entries 

<pre>
example.com    1;
*.example.com  1;
</pre> 

we can use only one 

<pre>
.example.com   1;
</pre>

* include — include values from a file. Multiple includes may be used.