| Related Modules mod_ext_filter mod_include |
Related Directives AddInputFilter AddOutputFilter ExtFilterDefine ExtFilterOptions SetInputFilter SetOutputFilter |
A filter is a process which 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 which are selectable using run-time
configuration directives. The set of filters which apply to
data can be manipulated with the SetInputFilter
and SetOutputFilter directives.
The only configurable filter currently included with the
Apache distribution is the INCLUDES filter which
is provided by mod_include
to process output for Server Side Includes. There is also an
experimental module called mod_ext_filter which allows
for external programs to be defined as filters.