C Fortran 77
PROGRAM HELLO
C MPI Parameters
INCLUDE 'mpif.h'
INTEGER RANK, SIZE, IERROR, LEN
CHARACTER*30 NAME
C All ranks initiate the message-passing environment.
C Each rank obtains information about itself and its environment.
C Start MPI.
CALL MPI_INIT(IERROR)
C Get number of ranks.
CALL MPI_COMM_SIZE(MPI_COMM_WORLD, SIZE, IERROR)
C Get rank.
CALL MPI_COMM_RANK(MPI_COMM_WORLD, RANK, IERROR)
C Get run-host name.
CALL MPI_GET_PROCESSOR_NAME(NAME,LEN,IERROR)
PRINT *, 'Runhost:', name, ' Rank:', RANK, ' of ', SIZE,
& 'ranks', ' hello, world'
C Terminate MPI.
CALL MPI_FINALIZE(IERROR)
END