Our first MPI example is already quite involved, but this is a hurdle we must overcome right at the beginning in order to be able to write messages to the display in a reasonably portable manner. This program is shown in the verbatim listing in the next section, 3.1. Like all other examples in this tutorial you can obtain it by ftp anonymous from cisr.anu.edu.au, directory /pub/papers/meglicki/mpi/simplempi. The file is called first.c.
This program does not come from the Argonne ``Using MPI...'' book and you will not find it in the Argonne ftp-anonymous directories. Their first program is much simpler than this one, but it makes certain assumptions about I/O, which are valid for MPICH, but which are not valid for LAM, or some other MPI implementations. So we must take this detour before we can merge with ``Using MPI...''.