How to Set Environment Variable in Linux: Simple Steps

To set an environment variable in Linux temporarily, use export VARIABLE_NAME=value in the terminal. For permanent settings, add the export command to your shell's configuration file like ~/.bashrc or ~/.profile.

Syntax

Use the export command to set an environment variable in the current shell session. The syntax is:

• export VARIABLE_NAME=value: Sets the variable VARIABLE_NAME to value for the current session.
• VARIABLE_NAME=value: Sets the variable only for the current command if used before a command.

bash

export VARIABLE_NAME=value

Example

This example shows how to set a temporary environment variable and check its value.

bash

export MY_VAR=hello

echo $MY_VAR

Output

hello

Common Pitfalls

One common mistake is setting a variable without export, which makes it unavailable to child processes. Another is forgetting to reload the shell configuration file after adding variables for permanence.

bash

MY_VAR=hello

echo $MY_VAR  # Works in current shell

bash -c 'echo $MY_VAR'  # No output because MY_VAR is not exported

# Correct way:
export MY_VAR=hello
bash -c 'echo $MY_VAR'  # Outputs 'hello'

Output

hello

Quick Reference

Action	Command	Description
Set temporary variable	export VAR=value	Available in current shell and child processes
Set variable for one command	VAR=value command	Only for that command execution
Make variable permanent	Add export VAR=value to ~/.bashrc	Loads on new shell sessions
Reload config file	source ~/.bashrc	Apply changes without logout

Key Takeaways

Use export VARIABLE_NAME=value to set environment variables for the current session.

Add export commands to ~/.bashrc or ~/.profile to make variables permanent.

Reload your shell config with source ~/.bashrc after editing to apply changes immediately.

Without export, variables are not passed to child processes.

Use VAR=value command to set a variable only for a single command execution.