NAME

MPI_Info_get_nkeys - Gets the number of keys currently defined in an info object.

SYNTAX

C Syntax

#include <mpi.h>
int MPI_Info_get_nkeys(MPI_Info info, int *nkeys)

Fortran Syntax

USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_INFO_GET_NKEYS(INFO, NKEYS, IERROR)
	INTEGER		INFO, NKEYS, IERROR

Fortran 2008 Syntax

USE mpi_f08
MPI_Info_get_nkeys(info, nkeys, ierror)
	TYPE(MPI_Info), INTENT(IN) :: info
	INTEGER, INTENT(OUT) :: nkeys
	INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

#include <mpi.h>
int MPI::Info::Get_nkeys() const

INPUT PARAMETER

info: Info object (handle).

OUTPUT PARAMETERS

nkeys: Number of defined keys (integer).
IERROR: Fortran only: Error status (integer).

DESCRIPTION

MPI_Info_get_nkeys returns the number of currently defined keys in info.

ERRORS

Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument. C++ functions do not return errors. If the default error handler is set to MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism will be used to throw an MPI::Exception object.

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 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.