Sams Teach Yourself Shell Programming in 24 Hours, Second Edition

Hour 12. Loops

Loops enable you to execute a series of commands multiple times. The two main types of loops are the while loop and the for loop. In addition to these two types of loops, ksh, bash, and zsh support an additional type of loop called the select loop. It can be used to present a menu of choices to a shell scripts user. In this chapter, you will examine loops in detail. Specifically, this chapter covers the following topics:

• The while loop

• The for loop

• The select loop

• Loop control