filter_list
  (PHP 5 >= 5.2.0, PECL filter:0.11.0)
filter_list — Returns a list of all supported filters
  
 
  Description
  
   array filter_list
    ( void
   )
  
 
  Return Values
  
   Returns an array of names of all supported filters, empty array if there
   are no such filters. Indexes of this array are not filter IDs, they can be
   obtained with filter_id() from a name instead.
  
  
 
  Examples
  
   
    Example #1 A filter_list() example
    
<?php
print_r(filter_list());
?>
     
    The above example will output 
something similar to:
Array
(
    [0] => int
    [1] => boolean
    [2] => float
    [3] => validate_regexp
    [4] => validate_url
    [5] => validate_email
    [6] => validate_ip
    [7] => string
    [8] => stripped
    [9] => encoded
    [10] => special_chars
    [11] => unsafe_raw
    [12] => email
    [13] => url
    [14] => number_int
    [15] => number_float
    [16] => magic_quotes
    [17] => callback
)