This document describes the use of filters in Apache.
A filter is a process that is applied to data that
is sent or received by the server. Data sent by clients to the
server is processed by input filters while data sent
by the server to the client is processed by output
filters. Multiple filters can be applied to the data, and
the order of the filters can be explicitly specified.
Filters are used internally by Apache to perform functions such
as chunking and byte-range request handling. In addition, modules
can provide filters that are selectable using run-time
configuration directives. The set of filters that apply to data
can be manipulated with the
The following user-selectable filters are currently provided
with the Apache HTTP Server distribution.
- Server-Side Includes processing by
- Compress output before sending it to the client using
In addition, the module
for external programs to be defined as filters.