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.

SEE ALSO

       MPI_Info_get
       MPI_Info_get_nthkey
       MPI_Info_get_valuelen

4.1.2                                             Nov 24, 2021                             MPI_Info_get_nkeys(3)