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The Linux Command Line

Cover of The Linux Command Line by William E. Shotts Jr. Published by No Starch Press

Chapter 31. Flow Control: Branching with case

In this chapter, we will continue to look at flow control. In Chapter 28, we constructed some simple menus and built the logic used to act on a user’s selection. To do this, we used a series of if commands to identify which of the possible choices had been selected. This type of construct appears frequently in programs, so much so that many programming languages (including the shell) provide a flow-control mechanism for multiple-choice decisions.


The bash multiple-choice compound command is called case. It has the following syntax:

case word in
        [pattern [| pattern]...) commands ;;]...

If we look at the read-menu program from Chapter 28, we see the logic used to act on a user’s selection

#!/bin/bash ...

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