unset Command: Tutorial & Examples
Unset the value of an environment variable
unset is a command used to remove a variable or function definition from the current shell environment. It is used to delete the value assigned to a variable, making it
unset or undefined. Once a variable is unset, it can no longer be used in the current shell session, and its value cannot be accessed.
The basic syntax of the unset command is:
For example, if you have a variable named
x with the value of
5, you can use unset
x to remove the variable and its value from the current shell session.
You can also use the
-v option to unset a variable:
unset -v variable-name
You can also use unset
-f to delete a function definition from the current shell environment:
unset -f function-name
It's important to note that once a variable or function is unset, it can no longer be accessed or used in the current shell session.
Also, if you are using this command inside a script, it will only delete the variable in the script's environment and not in the environment of the shell that calls the script.
It's a good practice to unset variables that you no longer need to free up memory and prevent confusion.