# include <stdlib.h>
# include <stdio.h>

# include "mpi_stubs_c.h"

int main ( int argc, char *argv[] );
void timestamp ( void );

/******************************************************************************/

int main ( int argc, char *argv[] )

/******************************************************************************/
/*
  Purpose:

    MAIN is the main program for HELLO.

  Discussion:

    HELLO is a simple MPI test program.

    Each process prints out a "Hello, world!" message.

    The master process also prints out a short message.

  Licensing:

    This code is distributed under the GNU LGPL license. 

  Modified:

    04 October 2005

  Author:

    John Burkardt

  Reference:

    William Gropp, Ewing Lusk, Anthony Skjellum,
    Using MPI: Portable Parallel Programming with the
    Message-Passing Interface,
    Second Edition,
    MIT Press, 1999,
    ISBN: 0262571323.
*/
{
  int ierr;
  int master = 0;
  int num_procs;
  int world_id;
/*
  Initialize MPI.
*/
  ierr = MPI_Init ( &argc, &argv );
/*
  Get the number of processes.
*/
  ierr = MPI_Comm_size ( MPI_COMM_WORLD, &num_procs );
/*
  Get the individual process ID.
*/
  ierr = MPI_Comm_rank ( MPI_COMM_WORLD, &world_id );
/*
  Process 0 prints an introductory message.
*/
  if ( world_id == master ) 
  {
    printf ( "\n" );
    printf ( "HELLO_WORLD - Master process:\n" );
    printf ( "  C version\n" );
    printf ( "\n" );
    printf ( "  An MPI example program.\n" );
    printf ( "\n" );
    printf ( "  The number of processes is %d.\n", num_procs );
    printf ( "\n" );
  }
/*
  Every process prints a hello.
*/
  printf ( "  Process %d says 'Hello, world!'\n", world_id );
/*
  Process 0 says goodbye.
*/
  if ( world_id == master )
  {
    printf ( "\n" );
    printf ( "HELLO_WORLD - Master process:\n" );
    printf ( "  Normal end of execution: 'Goodbye, world!'\n" );
  }
/*
  Shut down MPI.
*/
  ierr = MPI_Finalize ( );

  return 0;
}
/******************************************************************************/

void timestamp ( void )

/******************************************************************************/
/*
  Purpose:

    TIMESTAMP prints the current YMDHMS date as a time stamp.

  Example:

    31 May 2001 09:45:54 AM

  Licensing:

    This code is distributed under the GNU LGPL license. 

  Modified:

    24 September 2003

  Author:

    John Burkardt

  Parameters:

    None
*/
{
# define TIME_SIZE 40

  static char time_buffer[TIME_SIZE];
  const struct tm *tm;
  size_t len;
  time_t now;

  now = time ( NULL );
  tm = localtime ( &now );

  len = strftime ( time_buffer, TIME_SIZE, "%d %B %Y %I:%M:%S %p", tm );

  printf ( "%s\n", time_buffer );

  return;
# undef TIME_SIZE
}