mpi_file_seek(3)
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 posi
tion 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 nonportable 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.