“The designers of UNIX built the operating system from many
small commands. To get the most from UNIX, it’s essential that you
learn these commands and how they work together.“
“The key to working on UNIX systems is to understand-and take
advantage of-the underlying UNIX philosophy. Once you learn this,
you’ll find that you can more easily work on UNIX systems, and can
more easily pick up new commands and techniques. This is because
the UNIX philosophy permeates most of the operating system….”
“The UNIX command line, or shell, provides a number of ways to
link commands together, either as a convenience or to make a new,
more powerful command from smaller pieces. UNIX achieves this by
redirecting input and output.”