How to Set Environment Variables in Linux

Environment variables play an important role in shaping your Linux experience. They act like tiny configuration switches, storing key information programs and scripts. Understanding how to set in Linux show environment variables, and use these variables can get you to customize your environment and easily automate tasks. Managing in Linux set environment variables is important for customizing your system’s behavior and making it work just the way you want.

In this post, we will discuss the important knowledge of setting Linux environment variables, covering everything from basic commands to advanced techniques, that help your Linux system run smoothly and allow different programs to communicate effectively.

What are environment variables?

Applications and scripts need specific information to run correctly. This information is stored in environment variables, For instance, the PATH variable tells the system where to look for executable files when you run a command. The EDITOR variable specifies your preferred text editor. These are just a few examples, many environment variables exist each one having a specific purpose.

1. Viewing all variables

To view all the variables currently set in your system, use the set env variable Linux command:

env

The following image in Linux shows the environment variables below:

In the alternative case, the following command is also used to view all the variables:

printenv

These will display a list of all current environment variables in Linux and their values.

2. Viewing a specific variable

For specific variables, the Linux echo environment variable can be used with the $ prefix:

echo $HOME
echo $PATH

This will print the value of the specified variable.

3. Checking variable exists

In Linux get the environment variable by using the -v option with printenv:

printenv -v my_var

It will output the variable’s value if it exists, or nothing if it doesn’t.

4. Using search option

If you have an understanding of the grep command it will filter the output of env or printenv:

env | grep my_var
printenv | grep PATH

This helps locate specific variables within a long list.

Setting up environment variables in Linux

Environment variables approach temporary and permanent. As the name suggests, temporary variables are removed when you close the terminal, which is good for quick tasks, while permanent ones remain. The export command is important during the implementation.

The following briefly describes two main ways to set the env variable in Linux:

1. Temporarily: This sets the variable only for the current shell session. It’s handy for quick tasks but disappears when you close the terminal.
2. Permanently: This makes the variable available for all future shell sessions and even after reboots. It’s ideal for frequently used variables.

Temporary variable setting

The export command is the key in Linux to set variables to a temporary environment. Simply add the environment variable Linux:

export VARIABLE_NAME=VARIABLE_VALUE

For example, to set a temporary variable named my_color to the value blue, use the following command:

export my_color=blue

Permanent variable setting

There are two main ways to set environment variables permanently:

1. Adding to shell startup files:

Each shell has a startup file that gets executed whenever you open a new terminal. For Bash, it’s ~/.bashrc. Add the export command for your desired variable to this file. For example, to permanently set my_color to blue, add the following line to ~/.bashrc.

export my_color=blue

Remember to reload the startup file after making changes:

source ~/.bashrc

2. Editing system configuration:

For system-wide variables accessible to all users, edit the /etc/environment file. Follow the same format as your shell startup file:

my_color=blue

Once set, you can access your environment variables by prepending their names with a dollar sign. For example, to print the value of my_color, use:

echo $my_color

This will output blue according to settings.

Important Notes

The following are important notes that should taken during the setup of environment variables:

• Variable names are case-sensitive. MY_COLOR and my_color are different variables
• Use quotes for values containing spaces. For example, MY_PATH=”/home/user/bin”.
• The env command lists all current environment variables.
• The unset command removes a variable from your current session.
• For automation purposes, pass variables as arguments or within the script to personalize its behavior.

Conclusion

Environment variables offer a vast toolkit for customization and automation. Setting environment variables may seem like a technical skill, but with a little practice, it becomes second nature. Remember, these tiny data packets can significantly impact your Linux experience, making tasks more efficient.

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