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 results you expect first check for the $.
Here's an example using the command line:
$ a=1 $ echo a a $ echo $a 1 $ b="Jim" $ echo b b $ echo $b Jim
All variables in a Bash script are considered to be strings. This is different than in a programming language such as C, where everything is strongly typed. In the preceding example, a and b are strings even though they appear to be integers.
Here's a short script to get us started: