mpi_file_set_size(3openmpi) [osx man page]

MPI_File_set_size(3OpenMPI)											       MPI_File_set_size(3OpenMPI)

NAME

       MPI_File_set_size - Resizes a file (collective).

SYNTAX

       C Syntax
	   #include <mpi.h>
	   int MPI_File_set_size(MPI_File fh, MPI_Offset size)

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

C++ Syntax
       #include <mpi.h>
       void MPI::File::Set_size(MPI::Offset size)

INPUT PARAMETERS

       fh	 File handle (handle).

       size	 Size to truncate or expand file (integer).

OUTPUT PARAMETER

       IERROR	 Fortran only: Error status (integer).

DESCRIPTION

       MPI_File_set_size resizes the file associated with the file handle fh, truncating UNIX files as necessary. MPI_File_set_size is collective;
       all processes in the group must pass identical values for size.

       When using MPI_File_set_size on a UNIX file, if size is larger than the current file size, the file size becomes size. If size  is  smaller
       than  the  current file size, the file is truncated at the position defined by size (from the beginning of the file and measured in bytes).
       Regions of the file which have been previously written are unaffected.

       MPI_File_set_size does not affect the individual file pointers or the shared file pointer.

       Note that the actual amount of storage space cannot be allocated by MPI_File_set_size. Use MPI_File_preallocate to accomplish this.

       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 SIZE argument only for Fortran 90.  FORTRAN 77 users may use  the  non-portable
       syntax

	    INTEGER*MPI_OFFSET_KIND SIZE

       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_set_size(3OpenMPI)

MPI_File_seek_shared(3OpenMPI)											    MPI_File_seek_shared(3OpenMPI)

NAME

       MPI_File_seek_shared - Updates the global shared file pointer (collective).

SYNTAX

       C Syntax
	   #include <mpi.h>
	   int MPI_File_seek_shared(MPI_File fh, MPI_Offset offset,
			 int whence)

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

C++ Syntax
       #include <mpi.h>
       void MPI::File::Seek_shared(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_shared updates the shared 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.

       MPI_File_seek_shared  is  collective;  all  the	processes  in  the  communicator  group  associated  with  the	file  handle  fh must call
       MPI_File_seek_shared with the same offset and whence.  All processes in the communicator group are  synchronized  before  the  shared  file
       pointer is updated.

       The offset can be negative, which allows seeking backwards. It is erroneous to seek to a negative position in the view. The end of the view
       is defined to be the position of the next elementary data item, relative to the current view, following the last whole elementary data item
       accessible.

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_seek_shared(3OpenMPI)