Linux env command

The Linux env command allows users to modify the environment of a command or shell session. It can set or unset environment variables, as well as run a command in a modified environment. By using env, users can customize their environment to meet specific requirements, such as setting the PATH variable to locate executable files, defining custom variables, or altering default settings. The command is versatile and essential for managing the environment in Linux systems efficiently.

env Syntax:

env [OPTION]... [-] [NAME=VALUE]... [COMMAND [ARG]...]

Options:

Option	Description
-i	Start with an empty environment
-u	Remove variable from the environment

Parameters:

Parameter	Description
NAME=VALUE	Set the environment variable NAME to VALUE
COMMAND	Specify the command to run with the new environment
ARG	Arguments to pass to the specified COMMAND

Caution

Exercise caution while setting environment variables using the env command as it may affect the behavior of commands and programs within that environment.

Set a Custom Environment Variable

env MY_VAR="Hello, World!" echo $MY_VAR

Display the value of a custom environment variable that was set using the env command.

Display All Environment Variables

env

Display all environment variables set in the current shell using the env command without any arguments.

Clear All Environment Variables

env -i env

Clear all environment variables by running env with the -i option.

Override PATH Environment Variable

env -i PATH=/bin ls

Override the PATH environment variable temporarily using the env command when executing a command.

Tip

When using the env command in Linux, it’s important to remember that it is typically used to run a program or command in a modified environment. This can be useful for setting specific environmental variables or changing the behavior of a command by modifying the shell’s environment before executing it.

How do I use env in Linux?

To use the env command in Linux, execute the following command:

env --var_name=value command

How can I list all environmental variables with env in Linux?

To list all environmental variables with env in Linux, you can execute the following command:

env

How can I clear all environmental variables using env in Linux?

To clear all environmental variables using env in Linux, you can execute the following command:

env -i command

How can I set a specific environmental variable temporarily with env in Linux?

To set a specific environmental variable temporarily with env in Linux, you can execute the following command:

env VAR_NAME=value command

How can I specify a search path for the command to execute with env in Linux?

To specify a search path for the command to execute with env in Linux, you can use the following command:

env PATH=/new/path command

How do I display the version information of the env command in Linux?

To display the version information of the env command in Linux, you can execute the following command:

env --version

How can I run a command with a different shell using env in Linux?

To run a command with a different shell using env in Linux, you can execute the following command:

env SHELL=/path/to/shell command

Applications of the env command

• Providing a clean environment for executing a specific command
• Setting or overriding environment variables
• Running a command with specific environment configurations
• Checking the current environment variables
• Troubleshooting environment-related issues