osx man page for mpi_file_iwrite_at

MPI_File_iwrite_at(3OpenMPI)											      MPI_File_iwrite_at(3OpenMPI)

NAME
       MPI_File_iwrite_at - Writes a file at an explicitly specified offset (nonblocking, noncollective).

SYNTAX
       C Syntax
	   #include <mpi.h>
	   int MPI_File_iwrite_at(MPI_File fh, MPI_Offset offset,
		  void *buf, int count, MPI_Datatype datatype, MPI_Request *request)

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

C++ Syntax
       #include <mpi.h>
       MPI::Request MPI::File::Iwrite_at(MPI::Offset offset, const void* buf,
	    int count, const MPI::Datatype& datatype)

INPUT
/OUTPUT PARAMETER
       fh	 File handle (handle).

INPUT PARAMETERS
       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
       request	 Request object (handle).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION
       MPI_File_iwrite_at  is  a  nonblocking  version	of MPI_File_write_at. It 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_iwrite_at stores the number of datatype elements actually written in status.  All other fields of status	are  unde-
       fined. The request structure can be passed to MPI_Wait or MPI_Test, which will return a status with the number of bytes actually accessed.

       It is erroneous to call this function if MPI_MODE_SEQENTIAL mode was specified when the file was open.

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++ 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.

Open MPI 1.2							  September 2006				      MPI_File_iwrite_at(3OpenMPI)