MPI_File_seek(3OpenMPI) MPI_File_seek(3OpenMPI)
NAME
MPI_File_seek - Updates individual file pointers (noncollective).
SYNTAX
C Syntax
#include <mpi.h>
int MPI_File_seek(MPI_File fh, MPI_Offset offset,
int whence)
Fortran Syntax (see FORTRAN 77 NOTES)
INCLUDE 'mpif.h'
MPI_FILE_SEEK(FH, OFFSET, WHENCE, IERROR)
INTEGER FH, WHENCE, IERROR
INTEGER(KIND=MPI_OFFSET_KIND) OFFSET
C++ Syntax
#include <mpi.h>
void MPI::File::Seek(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 updates the individual 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.
The offset can be negative, which allows seeking backwards. It is erroneous to seek to a negative position
in the file. The end of the file is defined to be the location of the next elementary data item immediately
after the last accessed data item, even if that location is a hole.
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.
Open MPI 1.2 September 2006 MPI_File_seek(3OpenMPI)
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