(PHP 5)
stream_get_transports — Retrieve list of registered socket transports
Returns an indexed array containing the name of all socket transports available on the running system.
Example#1 Using stream_get_transports()
<?php
$xportlist = stream_get_transports();
print_r($xportlist);
?>
Output will be similar to the following. Note: there may be more or fewer transports in your version of PHP.
Array ( [0] => tcp [1] => udp [2] => unix [3] => udg )
See also stream_get_filters(), and stream_get_wrappers().