MPIFileread(3OpenMPI) MPIFileread(3OpenMPI)

NAME
       MMPPIIFFiilleerreeaadd  - Reads a file starting at the location specified by the
       individual file pointer (blocking, noncollective).


SSYYNNTTAAXX
       C Syntax
           #include 
           int MPIFileread(MPIFile fh, void *buf,
                  int count, MPIDatatype datatype, MPIStatus *status)

       Fortran Syntax
           INCLUDE 'mpif.h'
           MPIFILEREAD( FH,  BUF, COUNT,
                   DATATYPE, STATUS, IERROR)
                      BUF(*)
             INTEGER  FH, COUNT, DATATYPE, STATUS(MPISTATUSSIZE),
                      IERROR


CC++++ SSyynnttaaxx
       #include 
       void MPI::File::Read(void* buf, int count,
            const MPI::Datatype& datatype, MPI::Status& status)

       void MPI::File::Read(void* buf, int count,
            const MPI::Datatype& datatype)


IINNPPUUTT PPAARRAAMMEETTEERRSS
       fh        File handle (handle).

       count     Number of elements in buffer (integer).

       datatype  Data type of each buffer element (handle).


OOUUTTPPUUTT PPAARRAAMMEETTEERRSS
       buf       Initial address of buffer (integer).

       status    Status object (status).

       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       MPIFileread attempts to read from the file associated with fh (at the
       current  individual  file  pointer position maintained by the system) a
       total number of count data items having datatype type into  the  user's
       buffer buf.  The data is taken out of those parts of the file specified
       by the current view. MPIFileread stores the number of data-type  ele-
       ments  actually  read  in status.  All other fields of status are unde-
       fined.

       It is erroneous to call this function if MPIMODESEQUENTIAL  mode  was
       specified when the file was opened.


EERRRROORRSS
       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::ERRORSTHROWEXCEPTIONS, 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   MPIERRORSRETURN.   The   error   handler  may  be  changed  with
       MPIFileseterrhandler;     the     predefined      error      handler
       MPIERRORSAREFATAL  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         MPIFileread(3OpenMPI)