參考資料來源

 Cisco IOS.sh Variables

An Cisco IOS.sh variable is a way to simplify typing tasks and use long text or functions in a short symbol. Cisco IOS.sh variables can be created in EXEC mode. There cannot be any spaces between the variable name and the equal sign.

Creating a Variable

To create a variable name, use NAME=value with no space:
Router# VAR1=value1
Router# VAR2=value2

To retrieve the configuration state of the Cisco IOS.sh variables:
Router# show shell environment
VAR1=value1
VAR2=value2

To remove a variable, simply assign an empty value to the variable:
Router# VAR1=

Cisco IOS.sh variables are associated with a user's login session, so the Cisco IOS.sh variable set by one user is not visible to others.

Variable Substitution in CLI

A variable reference is done by using the "$" character in front of the name of the variable:

Router# abc=123
Router# echo $abc