How to Print Environment Variables in Linux

Linux is an open-source operating system that is widely used by developers, system administrators, and other IT professionals. One of the essential features of Linux is the ability to set and use environment variables. Environment variables are dynamic values that can be accessed by applications and scripts running on the Linux system. These variables contain data that can be used to configure and customize the behavior of many applications and tools.

In this article, we will explore how to print environment variables in Linux. We will cover the basics of environment variables, how to set and access them, and various methods to print environment variables in Linux.

What are Environment Variables?

Environment variables are dynamic values that are used by the operating system and applications running on the system. These variables are stored in memory and can be accessed by any application or script running on the system. Environment variables are used to configure and customize the behavior of many applications and tools.

Some of the common environment variables used in Linux include:

• PATH: This variable contains a list of directories that the shell searches when looking for a command to execute.
• HOME: This variable contains the home directory of the current user.
• USER: This variable contains the name of the current user.
• SHELL: This variable contains the path to the current shell.

Setting Environment Variables in Linux

In Linux, you can set environment variables using the export command. The syntax for setting an environment variable is as follows:

export VARIABLE_NAME=value

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

export MY_VAR=hello

You can also set environment variables in a shell script. In a shell script, you can set environment variables using the same syntax as above.

Accessing Environment Variables in Linux

To access an environment variable in Linux, you can use the $ symbol followed by the variable name. For example, to access the MY_VAR environment variable that we set earlier, you can use the following command:

echo $MY_VAR

This will print the value of the MY_VAR environment variable, which is hello.

Printing Environment Variables in Linux

There are several methods to print environment variables in Linux. Let’s explore some of the common methods:

Method 1: Using the printenv Command

The printenv command is a built-in command in Linux that prints all environment variables. To print all environment variables, you can use the following command:

printenv

This will print all environment variables in your shell session.

Method 2: Using the env Command

The env command is another built-in command in Linux that prints all environment variables. To print all environment variables, you can use the following command:

env

This will print all environment variables in your shell session.

Method 3: Using the echo Command

You can also print a specific environment variable using the echo command. To print a specific environment variable, you can use the following command:

echo $VARIABLE_NAME

For example, to print the MY_VAR environment variable that we set earlier, you can use the following command:

echo $MY_VAR

This will print the value of the MY_VAR environment variable, which is hello.

Conclusion

Environment variables are an essential feature of Linux that allows developers and system administrators to configure and customize the behavior of many applications and tools. In this article, we explored how to print environment variables in Linux using various methods. We also covered the basics of environment variables, how to set and access them, and various methods to print environment variables in Linux.

By understanding how to print environment variables in Linux, you can better manage and customize your Linux system to meet your needs.