This article is an excerpt from the new 2nd Ed. of Mark Sobell's book, A Practical Guide to Linux Commands, Editors, and Shell Programming, published Nov. 2009 by Prentice Hall Professional, ISBN 0131367366, Copyright 2010 Mark G. Sobell. For additional sample content from a selection of chapters, please visit the publisher site: www.informit.com/title/0131367366 more>>