php_user_filter::filter
  Called when applying the filter
  
 
  Description
  
   public int php_user_filter::filter
    ( resource $in
   , resource $out
   , int &$consumed
   , bool $closing
   )
  
  
 
  Parameters
  
   - 
    in
- 
     
      inis a resource pointing to a bucket brigade
      which contains one or more bucket objects containing data to be filtered.
 
- 
    out
- 
     
      outis a resource pointing to a second bucket brigade
      into which your modified buckets should be placed.
 
- 
    consumed
- 
     
      consumed, which must always
      be declared by reference, should be incremented by the length of the data
      which your filter reads in and alters.  In most cases this means you will
      incrementconsumedby $bucket->datalen
      for each $bucket.
 
- 
    closing
- 
     
      If the stream is in the process of closing
      (and therefore this is the last pass through the filterchain),
      the closingparameter will be set toTRUE.
 
 
 
  Return Values
  
   The  filter method must return one of
   three values upon completion.