How to delete an exported environment variable in Linux?

Short answer:

unset is the command you’re looking for.

unset GNUPLOT_DRIVER_DIR

How to delete an exported environment variable in Linux?

Walkthrough of creating and deleting an environment variable in Bash:

Test if the DUALCASE variable exists (empty output):

env | grep DUALCASE

It does not, so create the variable and export it:

DUALCASE=1
export DUALCASE

Check if it is there:

env | grep DUALCASE

Output:

DUALCASE=1

It is there. So get rid of it:

unset DUALCASE

Check if it’s still there (empty output):

env | grep DUALCASE

The DUALCASE exported environment variable is deleted.

Extra commands to help clear your local and environment variables:

Unset all local variables back to default on login:

CAN="chuck norris"
set | grep CAN

Output:

CAN=’chuck norris’

env | grep CAN # Empty output

exec bash
set | grep CAN
env | grep CAN # Empty output

exec bash command cleared all the local variables, but not environment variables.

Unset all environment variables back to default on login:

export DOGE="so wow"
env | grep DOGE

Output:

DOGE=so wow

env -i bash
env | grep DOGE # Empty output

env -i bash command cleared all the environment variables to default on login.

Answer #3:

The original question doesn’t mention how the variable was set, but:

In C shell (csh/tcsh) there are two ways to set an environment variable:

1. set x = "something"
2. setenv x "something"

The difference in the behaviour is that variables set with the setenv command are automatically exported to a subshell while variables set with set aren’t.

To unset a variable set with set, use

unset x

To unset a variable set with setenv, use

unsetenv x

Note: in all the above, I assume that the variable name is ‘x’.

Delete an exported environment variable in Linux by assigning an empty value:

This may also work.

export GNUPLOT_DRIVER_DIR=

Answer #5:

As mentioned in the above answers, unset GNUPLOT_DRIVER_DIR should work if you have used export to set the variable. If you have set it permanently in ~/.bashrc or ~/.zshrc then simply removing it from there will work.

Delete an exported environment variable using the env Command:

The env command runs a program in the modified environment. We can use this command to clear the value of an exported variable:

$ export file_name="test.txt"
$ env | grep file_name
file_name=test.txt
$ env -i bash
$ env | grep file_name

Here, we’re using the -i flag, which clears the variables exported by the user and starts a new session of Bash with default values.

Let’s exit from the new Bash session and verify that the variable is present in the older session:

$ exit
$ env | grep file_name
file_name=test.txt

Hope you learned something from this post.

Follow Programming Articles for more!