How do you list environment variables in Linux?

Listing environment variables in Linux can be done using several commands, each offering slightly different functionality. The correct answer is the command that most commonly displays all current environment variables along with their values.

When you use the command env, it prints out a list of all the environment variables currently set in your session. This command is particularly useful for viewing the environment portion of your shell and is often used in scripts to check what environment settings are available at a certain point.

While other commands like printenv and set can also show environment variables, env is widely recognized for its straightforward purpose of displaying the environment without extraneous information. The set command can show all shell variables and functions, which includes local variables that are not necessarily environment variables, making it less focused than env for this specific task. The command showenv is not a standard command in most Linux distributions for listing environment variables, which is why it is not the correct choice.

Overall, using env provides a clean and clear output of all environment variables, making it the best answer for comprehensively listing them in Linux.