.. include:: ../../global.rst

.. _`fd handles`:

FD Handles
----------

FD handles don't exist *per se* but abstract the idea of file
descriptor handles, ie. both file and pipe handles, giving a set of
commands that work for either.

You cannot open fd handles directly but must use a file or pipe handle
creation method.


FD Handle Predicates
^^^^^^^^^^^^^^^^^^^^


.. _`fd-handle?`:

.. idio:function:: fd-handle? o


   test if `o` is a fd handle			
   						
   :param o: object to test			
   :return: ``#t`` if `o` is a fd handle, ``#f`` otherwise	


.. _`input-fd-handle?`:

.. idio:function:: input-fd-handle? o


   test if `o` is an input fd handle		
   						
   :param o: object to test			
   :return: ``#t`` if `o` is an input fd handle, ``#f`` otherwise	


.. _`output-fd-handle?`:

.. idio:function:: output-fd-handle? o


   test if `o` is an output fd handle		
   						
   :param o: object to test			
   :return: ``#t`` if `o` is an output fd handle, ``#f`` otherwise	


FD Handle Attributes
^^^^^^^^^^^^^^^^^^^^


.. _`fd-handle-fd`:

.. idio:function:: fd-handle-fd fdh


   return the file descriptor associated with	
   fd handle `fdh`					
   						
   :param fdh: fd handle to query			
   :type fdh: fd handle				
   :return: file descriptor			
   :rtype: C/int					


FD Handle Functions
^^^^^^^^^^^^^^^^^^^


.. _`close-fd-handle-on-exec`:

.. idio:function:: close-fd-handle-on-exec fdh


   call :manpage:`fcntl(3)` on the C file descriptor associated with		
   fd handle `fdh` with `F_SETFD` and `FD_CLOEXEC` arguments	
   						
   :param fdh: fd handle to cloexec		
   :type fdh: fd handle				
   :return: 0					
   :rtype: C/int					
   :raises ^system-error:				




.. include:: ../../commit.rst