.. _mpi_info_get:


MPI_Info_get
============

.. include_body

:ref:`MPI_Info_get` - Retrieves the value associated with a key in an info
object.


SYNTAX
------


C Syntax
^^^^^^^^

.. code-block:: c

   #include <mpi.h>

   int MPI_Info_get(MPI_Info info, const char *key, int valuelen, char *value, int *flag)


Fortran Syntax
^^^^^^^^^^^^^^

.. code-block:: fortran

   USE MPI
   ! or the older form: INCLUDE 'mpif.h'
   MPI_INFO_GET(INFO, KEY, VALUELEN, VALUE, FLAG, IERROR)
   	INTEGER	INFO, VALUELEN, IERROR
   	CHARACTER*(*) KEY, VALUE
   	LOGICAL FLAG


Fortran 2008 Syntax
^^^^^^^^^^^^^^^^^^^

.. code-block:: fortran

   USE mpi_f08
   MPI_Info_get(info, key, valuelen, value, flag, ierror)
   	TYPE(MPI_Info), INTENT(IN) :: info
   	CHARACTER(LEN=*), INTENT(IN) :: key
   	INTEGER, INTENT(IN) :: valuelen
   	CHARACTER(LEN=valuelen), INTENT(OUT) :: value
   	LOGICAL, INTENT(OUT) :: flag
   	INTEGER, OPTIONAL, INTENT(OUT) :: ierror


INPUT PARAMETERS
----------------
* ``info``: Info object (handle).
* ``key``: Key (string).
* ``valuelen``: Length of value arg (integer).

OUTPUT PARAMETER
----------------
* ``value``: Value (string).
* ``flag``: Returns true if key defined, false if not (boolean).
* ``IERROR``: Fortran only: Error status (integer).

DESCRIPTION
-----------

:ref:`MPI_Info_get` retrieves the value associated with *key* in a previous
call to :ref:`MPI_Info_set`. If such a key exists, it sets *flag* to true and
returns the value in *value*; otherwise it sets *flag* to false and
leaves *value* unchanged. *valuelen* is the number of characters
available in value. If it is less than the actual size of the value, the
returned value is truncated. In C, *valuelen* should be one less than
the amount of allocated space to allow for the null terminator.

If *key* is larger than MPI_MAX_INFO_KEY, the call is erroneous.


ERRORS
------

Almost all MPI routines return an error value; C routines as the value
of the function and Fortran routines in the last argument.

Before the error value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job, except for
I/O function errors. The error handler may be changed with
:ref:`MPI_Comm_set_errhandler`; the predefined error handler MPI_ERRORS_RETURN
may be used to cause error values to be returned. Note that MPI does not
guarantee that an MPI program can continue past an error.


.. seealso::
   :ref:`MPI_Info_create` :ref:`MPI_Info_delete` :ref:`MPI_Info_dup` :ref:`MPI_Info_free`
   :ref:`MPI_Info_get_valuelen` :ref:`MPI_Info_get_nkeys` :ref:`MPI_Info_get_nthkey`
   :ref:`MPI_Info_set`
