Special Edition Using Linux®, Sixth Edition

Case Study: Scripting Suggestions

As part of furthering your knowledge in shell scripts, look at the scripts in /etc/rc.d/init.d. They will show you how a script can give a usage statement if it requires an argument (the case statements), how to test for conditions ([ equals test, but also requires a closing ] to terminate the test—enter man test for details), and proper use of variables. Other scripts you'll find on your Linux system will show you how to loop through a (sometimes previously undetermined) number of items using a for ..do .. done syntax (as in /etc/rc.d/rc. modules). Scripts can be a powerful ally. While you're learning, feel free to borrow from scripts on your system. Also look into sed and awk, which work with lines and paragraphs ...