MPIFileseekshared(3OpenMPI) MPIFileseekshared(3OpenMPI)

NAME
       MMPPIIFFiilleesseeeekksshhaarreedd  - Updates the global shared file pointer (collec-
       tive).


SSYYNNTTAAXX
       C Syntax
           #include 
           int MPIFileseekshared(MPIFile fh, MPIOffset offset,
                         int whence)

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


CC++++ SSyynnttaaxx
       #include 
       void MPI::File::Seekshared(MPI::Offset offset, int whence)


IINNPPUUTT PPAARRAAMMEETTEERRSS
       fh        File handle (handle).

       offset    File offset (integer).

       whence    Update mode (integer).


OOUUTTPPUUTT PPAARRAAMMEETTEERR
       IERROR    Fortran only: Error status (integer).


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

         o    MPISEEKSET - The pointer is set to offset.

         o    MPISEEKCUR  -  The pointer is set to the current pointer posi-
              tion plus offset.

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

MPIFileseekshared  is  collective;  all  the  processes in the communicator
group associated with the file handle fh must call  MPIFileseekshared  with
the  same offset and whence.  All processes in the communicator group are syn-
chronized 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.


FFOORRTTRRAANN 7777 NNOOTTEESS
       The  MPI  standard  prescribes  portable  Fortran syntax for the OFFSET
       argument only for Fortran 90.  FORTRAN 77 users may use the  non-porta-
       ble syntax

            INTEGER*MPIOFFSETKIND OFFSET

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


EERRRROORRSS
       Almost all MPI routines return an error value; C routines as the  value
       of  the  function  and Fortran routines in the last argument. C++ func-
       tions do not return errors. If the default  error  handler  is  set  to
       MPI::ERRORSTHROWEXCEPTIONS, 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  MPIERRORSRETURN.  The  error  handler   may   be   changed   with
       MPIFileseterrhandler;      the      predefined     error     handler
       MPIERRORSAREFATAL may be used to make I/O errors  fatal.  Note  that
       MPI  does not guarantee that an MPI program can continue past an error.




Open MPI 1.2                    September 2006  MPIFileseekshared(3OpenMPI)