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MPI_Init(3) man page (version 1.3.4)

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NAME

       MPI_Init - Initializes the MPI execution environment

SYNTAX


C Syntax

       #include <mpi.h>
       int MPI_Init(int *argc, char ***argv)

Fortran Syntax

       INCLUDE 'mpif.h'
       MPI_INIT(IERROR)
            INTEGER   IERROR

C++ Syntax

       #include <mpi.h>
       void MPI::Init(int& argc, char**& argv)
       void MPI::Init()

INPUT PARAMETERS

       argc      C/C++ only: Pointer to the number of arguments.

       argv      C/C++ only: Argument vector.

OUTPUT PARAMETER

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       This  routine,  or MPI_Init_thread, must be called before any other MPI
       routine (apart from MPI_Initialized) is called. MPI can be  initialized
       at most once; subsequent calls to MPI_Init or MPI_Init_thread are erro-
       neous.

       All MPI programs must contain a call to  MPI_Init  or  MPI_Init_thread.
       Open MPI accepts the C/C++ argc and argv arguments to main, but neither
       modifies, interprets, nor distributes them:

            {
                 /* declare variables */
                 MPI_Init(&argc, &argv);
                 /* parse arguments */
                 /* main program */
                 MPI_Finalize();
            }

NOTES

       The Fortran version does not have provisions  for  argc  and  argv  and
       takes only IERROR.

       The  MPI Standard does not say what a program can do before an MPI_Init
       or after an MPI_Finalize. In the Open MPI implementation, it should  do
       as  little  as possible. In particular, avoid anything that changes the
       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 the MPI man page for a full list of MPI error codes.

SEE ALSO

       MPI_Init_thread
       MPI_Initialized
       MPI_Finalize

1.3.4                            Nov 11, 2009                      MPI_Init(3)

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