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MPI_File_seek - Updates individual file pointers (noncollective).
C Syntax
#include <mpi.h>
int MPI_File_seek(MPI_File fh, MPI_Offset offset,
int whence)
USE MPI
! or the older form: INCLUDE ’mpif.h’
MPI_FILE_SEEK(FH, OFFSET, WHENCE, IERROR)
INTEGER FH, WHENCE, IERROR
INTEGER(KIND=MPI_OFFSET_KIND) OFFSET
USE mpi_f08
MPI_File_seek(fh, offset, whence, ierror)
TYPE(MPI_File), INTENT(IN) :: fh
INTEGER(KIND=MPI_OFFSET_KIND), INTENT(IN) :: offset
INTEGER, INTENT(IN) :: whence
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
- fh
- File handle (handle).
- offset
- File offset (integer).
- whence
- Update mode (integer).
- IERROR
- Fortran only: Error status
(integer).
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.
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.
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.
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