MPI_File_seek_shared(3)            Open MPI            MPI_File_seek_shared(3)



NAME
       MPI_File_seek_shared - Updates the global shared file pointer
       (collective).


SYNTAX
       C Syntax
           #include <mpi.h>
           int MPI_File_seek_shared(MPI_File fh, MPI_Offset offset,
                         int whence)

       Fortran Syntax (see FORTRAN 77 NOTES)
           INCLUDE 'mpif.h'
           MPI_FILE_SEEK_SHARED(FH, OFFSET, WHENCE, IERROR)
                  INTEGER FH, WHENCE, IERROR
                  INTEGER(KIND=MPI_OFFSET_KIND) OFFSET


C++ Syntax
       #include <mpi.h>
       void MPI::File::Seek_shared(MPI::Offset offset, int whence)


INPUT PARAMETERS
       fh        File handle (handle).

       offset    File offset (integer).

       whence    Update mode (integer).


OUTPUT PARAMETER
       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       MPI_File_seek_shared updates the shared file pointer according to
       whence, which could have the following possible values:

         o    MPI_SEEK_SET - The pointer is set to offset.

         o    MPI_SEEK_CUR - The pointer is set to the current pointer
              position plus offset.

         o    MPI_SEEK_END - The pointer is set to the end of the file plus
              offset.

       MPI_File_seek_shared is collective; all the processes in the
       communicator group associated with the file handle fh must call
       MPI_File_seek_shared with the same offset and whence.  All processes in
       the communicator group are synchronized before the shared file pointer
       is updated.


       The offset can be negative, which allows seeking backwards. It is
       erroneous to seek to a negative position in the view. The end of the
       view is defined to be the position of the next elementary data item,
       relative to the current view, following the last whole elementary data
       item accessible.


FORTRAN 77 NOTES
       The MPI standard prescribes portable Fortran syntax for the OFFSET
       argument only for Fortran 90.  FORTRAN 77 users may use the non-
       portable syntax

            INTEGER*MPI_OFFSET_KIND OFFSET

       where MPI_OFFSET_KIND is a constant defined in mpif.h and gives the
       length of the declared integer in bytes.


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. For MPI I/O function errors, the default error handler is set
       to MPI_ERRORS_RETURN. The error handler may be changed with
       MPI_File_set_errhandler; the predefined error handler
       MPI_ERRORS_ARE_FATAL may be used to make I/O errors fatal. Note that
       MPI does not guarantee that an MPI program can continue past an error.




1.4.1                            Jan 14, 2010          MPI_File_seek_shared(3)
