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How To Set Global Environment Variables for All Users in Ubuntu

Ubuntu 15

In this article, we will explore how to set global environment variables for all users in Ubuntu. Environment variables are a fundamental part of developing and running software, often used to make configuration settings available to an application’s runtime environment. Setting these variables globally ensures they are accessible to all users and sessions.

Quick Answer

To set global environment variables for all users in Ubuntu, you can use the /etc/environment file. Simply open the file with root permissions, add your environment variables in the NAME=VALUE format, save and close the file. The changes will take effect at the next login or after a reboot.

Understanding Environment Variables

Environment variables are dynamic named values stored within the system that are used by applications launched in shells or subshells. In Ubuntu, environment variables can be set on a user level or system-wide level.

Setting Global Environment Variables

To set a global environment variable for all users, we can use the /etc/environment file. This file is a system-wide configuration file, which is executed when the system boots up and sets environment variables for all users.

Here’s how you can do it:

  1. Open the /etc/environment file in a text editor with root permissions. For instance, you can use nano:
sudo nano /etc/environment
  1. Add your environment variable in a NAME=VALUE format. For example, to set a variable named TEST_VARIABLE with a value of test, you would add:
TEST_VARIABLE=test
  1. Save and close the file. If you’re using nano, you can do this by pressing Ctrl+X, then Y to confirm saving changes, and finally Enter to confirm the filename.
  2. The changes will take effect at the next login or after a reboot.

Please note that the /etc/environment file does not support shell-specific configurations or variable interpolation. This means you cannot use variables within variable values in this file.

Applying Changes Immediately

If you want the changes to apply immediately without needing to reboot or re-login, you can use the source command:

source /etc/environment

This command reads and executes commands from the /etc/environment file, which updates the environment variables for the current session. However, this will only affect your current session. Other users will not be affected until they start a new session or run the above command in their own session.

Setting Environment Variables for Bash Shell

If you need to set environment variables specifically for the Bash shell, you should use other files such as /etc/profile, /etc/profile.d/*.sh, ~/.profile, or ~/.bashrc.

For instance, to add an environment variable for all users, you can create a new script in the /etc/profile.d/ directory:

sudo nano /etc/profile.d/myenvvars.sh

In this script, you can add your environment variables:

export TEST_VARIABLE=test

After saving and closing the file, make it executable:

sudo chmod +x /etc/profile.d/myenvvars.sh

This approach is more reliable than directly editing the /etc/environment file, as it avoids potential conflicts when packages are updated.

Conclusion

Setting global environment variables in Ubuntu is a straightforward process, but it’s important to understand the different methods and when to use them. Whether you choose to use the /etc/environment file or shell-specific files like /etc/profile.d/*.sh will depend on your specific needs and the scope of the environment variables you want to set.

Can I set environment variables for specific users only?

Yes, you can set environment variables for specific users by modifying their respective shell configuration files such as ~/.profile or ~/.bashrc. These files are executed when the user logs in and can contain custom environment variable settings.

How can I view the current environment variables?

To view the current environment variables, you can use the printenv or env command in the terminal. Running either of these commands will display a list of all the current environment variables and their values.

Can I delete or remove environment variables?

Yes, you can delete or remove environment variables. To do this, you can use the unset command followed by the name of the variable you want to remove. For example, to remove a variable named TEST_VARIABLE, you would run unset TEST_VARIABLE.

How can I check if an environment variable is set?

You can check if an environment variable is set by using the echo command followed by the variable name. For example, to check if a variable named TEST_VARIABLE is set, you would run echo $TEST_VARIABLE. If the variable is set, its value will be displayed. If it is not set, nothing will be displayed.

Can I set environment variables from a script?

Yes, you can set environment variables from a script. Simply use the export command followed by the variable name and its value. For example, export TEST_VARIABLE=test will set the variable TEST_VARIABLE to the value test. Note that variables set in a script will only be available within the scope of that script unless they are exported to the environment using the export command.

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