Problem - Kevin Tafuro

Solution
Modern operating systems support a variety of interprocess communications primitives
that vary from system to system. If you intend to make your program portable
among different platforms and even different implementations of Unix, your best bet
is to use sockets. All modern operating systems support the Berkeley socket interface
for TCP/IP at a minimum, while most—if not all—Unix implementations also support
Unix domain sockets.
Discussion
Many operating systems support various methods of allowing two or more processes
to communicate with each other. Most systems (including both Unix and Windows)
support anonymous and named pipes. Many Unix systems (including BSD) also support
message queues, which have their origins in AT&T’s System V Unix. Windows
systems have a similar construct known as mailslots. Unix systems also have Unix
domain sockets, which share the Berkeley socket interface with TCP/IP sockets.
Here’s an overview of common mechanisms:
Anonymous pipes
Anonymous pipes are useful for communication between a parent and a child
process. The parent can create the two endpoints of the pipe before spawning
the child process, and the child process will inherit the file descriptors from the
parent. There are ways on both Unix and Windows for two otherwise unrelated
processes to exchange file descriptors, but this is rarely done. On Unix, you can
use Unix Domain sockets. On Windows, you can use the OpenProcess( ) and
DuplicateHandle( ) Win32 API functions.
Named pipes
Instead of using anonymous pipes between unrelated processes, a better solution
may be to use named pipes. With named pipes, a process can create a pipe
that has a name associated with it. Another process that knows the name of the
pipe can then open the pipe. On Unix, named pipes are actually special files created
in the filesystem, and the name used for the pipe is the name of that special
file. Windows uses a special namespace in the kernel and does not actually use
the filesystem at all, although the restrictions on the names given to pipes are
similar to those for files. Pipes work well when there are only two processes
involved, but adding additional processes to the mix quickly complicates matters.
Pipes were not designed for use by more than two processes at a time and
we strongly advise against attempting to use pipes in this way.
Message queues (Unix)
Unix message queues are named with an arbitrary integer value called a key.
Often a file is created, and that file’s inode is used as the key for the message
queue. Any process that has permission to read from the message queue can do
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