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