(PHP 5)
stream_get_filters — Retrieve list of registered filters
Returns an indexed array containing the name of all stream filters available on the running system.
Example #1 Using stream_get_filters()
<?php
$streamlist = stream_get_filters();
print_r($streamlist);
?>
Output will be similar to the following. Note: there may be more or fewer filters in your version of PHP.
Array ( [0] => string.rot13 [1] => string.toupper [2] => string.tolower [3] => string.base64 [4] => string.quoted-printable )
See also stream_filter_register(), and stream_get_wrappers().