=================
WSGIRestrictStdin
=================

:Description: Enable restrictions on use of STDIN.
:Syntax: ``WSGIRestrictStdin On|Off``
:Default: ``WSGIRestrictStdin Off``
:Context: server config

A well behaved Python WSGI application should never attempt to read any
input directly from ``sys.stdin``. This is because ways of hosting WSGI
applications such as CGI use standard input as the mechanism for receiving
the content of a request from the web server. If a WSGI application were to
directly read from ``sys.stdin`` it could interfere with the operation of
the WSGI adapter and result in corruption of the input stream.

When this directive is set to ``On``, mod_wsgi replaces ``sys.stdin``
with a restricted object that will raise an exception if an attempt is
made to use it::

  WSGIRestrictStdin On

This restriction is off by default since mod_wsgi 3.0, as the original
intent of promoting portable WSGI code proved ineffective in practice.
When the restriction is off, ``sys.stdin`` is whatever the hosting
process inherits, typically a closed or ``/dev/null`` stream, and
reads from it will return no data.

The directive is also valid inside a :doc:`WSGIInterpreterOptions`
container. When nested, the setting applies only to interpreters
matched by the container's selectors and overrides the top-level
value for those interpreters.