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++ 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.