..
  Copyright 1988-2022 Free Software Foundation, Inc.
  This is part of the GCC manual.
  For copying conditions, see the copyright.rst file.

.. index:: environment variable

.. _runtime:

Runtime:  Influencing runtime behavior with environment variables
-----------------------------------------------------------------

The behavior of the :command:`gfortran` can be influenced by
environment variables.

Malformed environment variables are silently ignored.

.. toctree::
  :maxdepth: 2

  runtime/tmpdir
  runtime/gfortranstdinunit
  runtime/gfortranstdoutunit
  runtime/gfortranstderrunit
  runtime/gfortranunbufferedall
  runtime/gfortranunbufferedpreconnected
  runtime/gfortranshowlocus
  runtime/gfortranoptionalplus
  runtime/gfortranlistseparator
  runtime/gfortranconvertunit
  runtime/gfortranerrorbacktrace
  runtime/gfortranformattedbuffersize
  runtime/gfortranunformattedbuffersize