How to see environment variables in Linux?

How to See Environment Variables in Linux

Introduction

Linux is a popular operating system known for its flexibility and customization options. One of the key features that makes Linux unique is its ability to store and manage environment variables. These variables are used to configure various aspects of the system, such as user permissions, file permissions, and even the display settings. In this article, we will explore how to see environment variables in Linux.

What are Environment Variables?

Environment variables are variables that are stored in the system’s environment, which is a collection of settings that are used to configure the system. These variables are used to configure various aspects of the system, such as user permissions, file permissions, and even the display settings. Environment variables are typically stored in the ~/.bashrc or ~/.bash_profile file, which is a file that is executed when the user logs in to the system.

How to See Environment Variables in Linux

To see environment variables in Linux, you can use the echo command with the -n option to display the variable names, or the echo command with the -e option to display the variable values. Here are some examples:

• echo -n "Variable Name: $Variable Value": This command will display the variable name and value.
• echo -e "Variable Name: $Variable Value": This command will display the variable name and value, followed by a newline character.

Using echo Command with -n Option

The echo command with the -n option is used to display the variable names without displaying the variable values. Here’s an example:

echo -n "Variable Name: $Variable Value"

This will display the variable name followed by a newline character.

Using echo Command with -e Option

The echo command with the -e option is used to display the variable values. Here’s an example:

echo -e "Variable Name: $Variable Value"

This will display the variable value followed by a newline character.

Using export Command

The export command is used to set environment variables. Here’s an example:

export VariableName=VariableValue

This will set the variable name and value.

Using unset Command

The unset command is used to unset environment variables. Here’s an example:

unset VariableName

This will unset the variable name.

Using source Command

The source command is used to source a shell configuration file. Here’s an example:

source ~/.bashrc

This will source the ~/.bashrc file, which will set the environment variables.

Using echo Command with env Option

The echo command with the env option is used to display environment variables. Here’s an example:

echo env

This will display the environment variables.

Using getenv Command

The getenv command is used to get the value of an environment variable. Here’s an example:

getenv VariableName

This will display the value of the variable name.

Using unsetenv Command

The unsetenv command is used to unset an environment variable. Here’s an example:

unsetenv VariableName

This will unset the variable name.

Using unsetenv Command with --all Option

The unsetenv command with the --all option is used to unset all environment variables. Here’s an example:

unsetenv --all

This will unset all environment variables.

Table: Environment Variables in Linux

Variable	Description	Value
PATH	The directory where the system searches for executables	/usr/bin:/bin:/usr/sbin:/sbin
HOME	The user’s home directory	/home/$USER
USER	The current user’s name	username
GROUP	The current user’s group	groupname
SHELL	The shell to use when logging in	/bin/bash
TERM	The terminal type	xterm
TERMINFO	Additional terminal information	xterm-256color

Conclusion

In this article, we have explored how to see environment variables in Linux. We have covered the different ways to display environment variables, including using the echo command with the -n option, -e option, and export command. We have also covered the source command, echo command with the env option, getenv command, and unsetenv command. Finally, we have covered the unsetenv command with the --all option. By following these steps, you can easily see and manage environment variables in Linux.

Additional Tips

• To set environment variables, use the export command.
• To unset environment variables, use the unset command.
• To source a shell configuration file, use the source command.
• To display environment variables, use the echo command with the env option.
• To get the value of an environment variable, use the getenv command.
• To unset all environment variables, use the unsetenv command with the --all option.