MPI_File_write_at(3) Open MPI MPI_File_write_at(3)NAMEMPI_File_write_at - Writes a file at an explicitly specified offset
(blocking, noncollective).
SYNTAX
C Syntax
#include <mpi.h>
int MPI_File_write_at(MPI_File fh, MPI_Offset offset, const void *buf,
int count, MPI_Datatype datatype, MPI_Status *status)
Fortran Syntax (see FORTRAN 77 NOTES)
INCLUDE 'mpif.h'
MPI_FILE_WRITE_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::Write_at(MPI::Offset offset, const void* buf,
int count, const MPI::Datatype& datatype, MPI::Status& status)
void MPI::File::Write_at(MPI::Offset offset, const void* buf,
int count, const MPI::Datatype& datatype)
INPUT PARAMETERS
fh File handle (handle).
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
status Status object (status).
IERROR Fortran only: Error status (integer).
DESCRIPTIONMPI_File_write_at 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_write_at stores the number of
datatype elements actually written in status. All other fields of sta‐
tus 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-porta‐
ble 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.
SEE ALSO
MPI_File_iwrite_at
MPI_File_write_at_all
MPI_File_write_at_all_begin
MPI_File_write_at_all_end
1.7.4 Feb 04, 2014 MPI_File_write_at(3)
