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MPI_File_write_at(3) man page (version 1.2.9)

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NAME

       MPI_File_write_at  -  Writes  a  file at an explicitly specified offset
       (blocking, noncollective).

SYNTAX

       C Syntax
           #include <mpi.h>
           int MPI_File_write_at(MPI_File fh, MPI_Offset offset, void *buf,
                  int count, MPI_Datatype datatype, MPI_Status *status)

       Fortran Syntax (see FORTRAN 77 NOTES)
           INCLUDE 'mpif.h'
           MPI_FILE_WRITE_AT(FH,  OFFSET,  BUF, COUNT,
                   DATATYPE, STATUS,  IERROR)
             <type>   BUF(*)
             INTEGER FH, COUNT, DATATYPE, STATUS(MPI_STATUS_SIZE), IERROR
             INTEGER(KIND=MPI_OFFSET_KIND) OFFSET

C++ Syntax

       #include <mpi.h>
       void MPI::File::Write_at(MPI::Offset offset, const void* buf,
            int count, const MPI::Datatype& datatype, MPI::Status& status)

       void MPI::File::Write_at(MPI::Offset offset, const void* buf,
            int count, const MPI::Datatype& datatype)

INPUT PARAMETERS

       fh        File handle (handle).

       offset    File offset (integer).

       buf       Initial address of buffer (choice).

       count     Number of elements in buffer (integer).

       datatype  Data type of each buffer element (handle).

OUTPUT PARAMETERS

       status    Status object (status).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       MPI_File_write_at attempts to write into the file  associated  with  fh
       (at  the  offset  position)  a  total number of count data items having
       datatype type from the user's buffer buf.  The offset is in etype units
       relative  to  the  current  view.  That  is, holes are not counted when
       locating an offset. The data is written into those parts  of  the  file
       specified  by  the current view. MPI_File_write_at stores the number of
       datatype elements actually written in status.  All other fields of sta-
       tus are undefined.

       It  is  erroneous to call this function if MPI_MODE_SEQUENTIAL mode was
            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++  func-
       tions  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.

SEE ALSO

       MPI_File_iwrite_at
       MPI_File_write_at_all
       MPI_File_write_at_all_begin
       MPI_File_write_at_all_end

Open MPI 1.2                    September 2006     MPI_File_write_at(3OpenMPI)

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