Linux Shell Scripting Bootcamp

Chapter 2. Working with Variables

This chapter will show how variables are used in a Linux system and in scripts.

The topics covered in this chapter are:

• Using variables in scripts
• Validating parameters using conditional statements
• Comparison operators for strings
• Environment variables

Using variables in scripts

A variable is simply a placeholder for some value. The value can change; however, the variable name will always be the same. Here is a simple example:

   a=1

This assigns the value 1 to variable a. Here's another one:

   b=2

To display what a variable contains use the echo statement:

   echo Variable a is: $a

Note

Notice the $ preceding the variable name. This is required in order to show the contents of the variable.

If at anytime, you aren't seeing the ...