Mastering Linux Shell Scripting - Second Edition

User-defined variables

To declare a variable, just type the name you want and set its value using the equals sign (=).

Check out this example:

#!/bin/bash 
name="Mokhtar" 
age=35 
total=16.5 
echo $name  #prints Mokhtar 
echo $age   #prints 35 
echo $total #prints 16.5 

As you can see, to print the variable's value, you should use the dollar sign ($) before it.

Note that there are no spaces between the variable name and the equals sign, or between the equals sign and the value.

If you forget and type a space in between, the shell will treat the variable as if it were a command, and, since there is no such command, it will show an error.

All of the following examples are incorrect declarations:

# Don't declare variables like this: name = "Mokhtar" ...