Unix: Visual QuickStart Guide

Creating if-then statements

The basic principle of if-then statements is that if a certain condition is met, then one thing happens; if the condition is not met, then another thing happens. That is, if you walk into your office in the morning and you see your daily ToDo list, then you sit down and work. If you walk into your office in the morning and you don't see your ToDo list, then you get to lounge all day. Or something like that.

As Figure 10.6 shows, you can create if-then statements using if, then, and else commands. When you set up these conditional statements, the computer then has to test the condition to determine whether it's true or false, and act accordingly. In the next example, we set up a fairly simple if-then conditional statement, ...