How to set environment variable in Linux?

Setting Environment Variables in Linux

Setting environment variables in Linux is a crucial step in customizing the system to your liking. Environment variables are used to store settings that can be accessed by various programs and services. In this article, we will guide you through the process of setting environment variables in Linux.

What are Environment Variables?

Environment variables are variables that are stored in the system’s environment. They are used to store settings that can be accessed by various programs and services. Environment variables are typically set using the export command, which is used to set the variable and make it available to all programs and services.

Why Set Environment Variables?

Setting environment variables is essential for several reasons:

Customization: Environment variables allow you to customize your system to your liking. You can set variables that are specific to your needs, such as the default text editor or the location of your favorite program.

Security: Environment variables can be used to store sensitive information, such as passwords or encryption keys. By setting environment variables securely, you can protect your system from unauthorized access.

Program Compatibility: Environment variables can be used to ensure that programs and services are compatible with each other. For example, you can set environment variables to ensure that a program is installed at the correct location.

How to Set Environment Variables in Linux

Setting environment variables in Linux is a straightforward process. Here are the steps to follow:

Table of Contents

Step 1: Set Environment Variables Using the `export` Command

The export command is used to set environment variables. To set an environment variable, you can use the following syntax:

export VARIABLE_NAME=VARIABLE_VALUE

For example, to set the PATH environment variable, you can use the following command:

export PATH=$PATH:/usr/local/bin

Step 2: Set Environment Variables Using the `export` Command with a File

You can also set environment variables using a file. To do this, you can create a file with the following syntax:

export VARIABLE_NAME=VARIABLE_VALUE

For example, to set the PATH environment variable, you can create a file called ~/.bashrc with the following content:

export PATH=$PATH:/usr/local/bin

Step 3: Set Environment Variables Using the `export` Command with a Shell Script

You can also set environment variables using a shell script. To do this, you can create a file with the following syntax:

#!/bin/bash

export VARIABLE_NAME=VARIABLE_VALUE

For example, to set the PATH environment variable, you can create a file called set_path.sh with the following content:

#!/bin/bash

export PATH=$PATH:/usr/local/bin

Step 4: Set Environment Variables in a User-Defined Script

You can also set environment variables in a user-defined script. To do this, you can create a file with the following syntax:

#!/bin/bash

export VARIABLE_NAME=VARIABLE_VALUE

For example, to set the PATH environment variable, you can create a file called set_path.sh with the following content:

#!/bin/bash

export PATH=$PATH:/usr/local/bin

Step 5: Set Environment Variables in a System File

You can also set environment variables in a system file. To do this, you can create a file with the following syntax:

export VARIABLE_NAME=VARIABLE_VALUE

For example, to set the PATH environment variable, you can create a file called /etc/profile with the following content:

export PATH=$PATH:/usr/local/bin

Step 6: Set Environment Variables in a User-Defined File

You can also set environment variables in a user-defined file. To do this, you can create a file with the following syntax:

export VARIABLE_NAME=VARIABLE_VALUE

For example, to set the PATH environment variable, you can create a file called ~/.bashrc with the following content:

export PATH=$PATH:/usr/local/bin

Step 7: Set Environment Variables in a System File (Using `systemd`)

You can also set environment variables in a system file using systemd. To do this, you can create a file with the following syntax:

[Unit]

Description=Environment Variable

After=network.target



[Service]

User=<username>

ExecStart=/usr/bin/env export VARIABLE_NAME=VARIABLE_VALUE

Restart=always



[Install]

WantedBy=multi-user.target