There is a easy way to allow developers to stop bugging us the system adminsitror, “clean the cache”.
Just setup this php page on a apache server and they can do it themselves.
Tested on Varnish 2.X using syntax:
curl -X PURGE http://localhost:81/site/bavidor/_img/*
It is also important to have the .vcl correclty configured as follows:

acl purge {
        "localhost";
        "10.51.34.99";
        "10.55.2.1";
}
sub vcl_recv {
        if (req.request == "PURGE") {
                if (!client.ip ~ purge) {
                        error 405 "Not allowed.";
                 } else {
                        purge_url(req.url);
                        error 200 "Purged";
                }
        }

here is the script:
Limpar Cache Varnish ASP

 ";
print "URL $URL  
";
print "Examplos: /blogs/vidor/*  ou /blogs/* 
";
print "

";
$hostname = 'cache221';
purgeURL( $hostname, $port, $URL, $debug );
$hostname = 'cache222';
purgeURL( $hostname, $port, $URL, $debug );
function purgeURL( $hostname, $port, $purgeURL, $debug )
{
    $finalURL = sprintf(
        "http://%s:%d%s", $hostname, $port, $purgeURL
    );
    print( "
 Purging ${finalURL} 

" );
    $curlOptionList = array(
        CURLOPT_RETURNTRANSFER    => true,
        CURLOPT_CUSTOMREQUEST     => 'PURGE',
        CURLOPT_HEADER            => true ,
        CURLOPT_NOBODY            => true,
        CURLOPT_URL               => $finalURL,
        CURLOPT_CONNECTTIMEOUT_MS => 2000
    );
    $fd = true;
    if( $debug == true ) {
        print "
---- Curl debug -----
";
        $fd = fopen("php://output", 'w+');
        $curlOptionList[CURLOPT_VERBOSE] = true;
        $curlOptionList[CURLOPT_STDERR]  = $fd;
    }
    $curlHandler = curl_init();
    curl_setopt_array( $curlHandler, $curlOptionList );
    $return = curl_exec($curlHandler);
    if(curl_error($curlHandler)) {
	print "

CRITICAL - Error to connect to $hostname port $port - Error:  curl_error($curl) 
";
    exit(2);
 }
    curl_close( $curlHandler );
    if( $fd !== false ) {
        fclose( $fd );
    }
    if( $debug == true ) {
    	print "
 Output: 

 $return 

";
    }
}
?>






URL:

ref.
http://blog.feryn.eu/2010/11/varnish-cache-purging/