mpi_file_get_byte_offset(3openmpi) [osx man page]

MPI_File_get_byte_offset(3OpenMPI)										MPI_File_get_byte_offset(3OpenMPI)

NAME

       MPI_File_get_byte_offset - Converts a view-relative offset into an absolute byte position.

SYNTAX

       C Syntax
	   #include <mpi.h>
	   int MPI_File_get_byte_offset(MPI_File fh, MPI_Offset offset,
		  MPI_Offset *disp)

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

C++ Syntax
       #include <mpi.h>
       MPI::Offset MPI::File::Get_byte_offset(const MPI::Offset disp)
	    const

INPUT PARAMETERS

       fh	 File handle (handle).

       offset	 Offset (integer).

OUTPUT PARAMETERS

       disp	 Absolute byte position of offset (integer).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       MPI_File_get_byte_offset  converts an offset specified for the current view to its corresponding displacement value, or absolute byte posi-
       tion, from the beginning of the file. The absolute byte position of offset relative to the current view of fh is returned in disp.

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

	    INTEGER*MPI_OFFSET_KIND OFFSET
       or
	    INTEGER*MPI_OFFSET_KIND DISP

       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_get_byte_offset(3OpenMPI)

MPI_File_read_at(3OpenMPI)												MPI_File_read_at(3OpenMPI)

NAME

       MPI_File_read_at - Reads a file at an explicitly specified offset (blocking, noncollective).

SYNTAX

       C Syntax
	   #include <mpi.h>
	   int MPI_File_read_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_READ_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::Read_at(MPI::Offset offset, void* buf,
	    int count, const MPI::Datatype& datatype,
	    MPI::Status& status)

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

INPUT PARAMETERS

       fh	 File handle (handle).

       offset	 File offset (integer).

       count	 Number of elements in buffer (integer).

       datatype  Data type of each buffer element (handle).

OUTPUT PARAMETERS

       buf	 Initial address of buffer (choice).

       status	 Status object (status).

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       MPI_File_read_at  attempts  to  read  from  the	file associated with fh (at the offset position) a total number of count data items having
       datatype type into 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 taken out of those parts of the file specified by the current view. MPI_File_read_at stores the number of
       datatype elements actually read in status.  All other  fields  of  status  are  undefined.  It  is  erroneous  to  call	this  function	if
       MPI_MODE_SEQUENTIAL mode was specified when the file was opened.

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_read_at(3OpenMPI)