Mastering the Linux export Command: A Beginner’s Guide to Environment Variables

How to Use the Linux export Command

The export command marks variables that should be passed to child processes, providing a simple yet powerful way for administrators to share environment configuration without restarting the session.

1. Display All Exported Variables

Running export without arguments lists every exported variable and its value. linuxmi@linuxmi:~$ export Use grep to filter the list, for example:

linuxmi@linuxmi:~$ export LINUXMI="Welcome to linuxmi.com"<br/>linuxmi@linuxmi:~$ export | grep -i linuxmi

2. Show Exported Variables of the Current Shell

The -p flag prints the current shell’s exported variables.

linuxmi@linuxmi:~$ export -p

3. Export a Variable

You can assign a value and export it in one step, e.g.: linuxmi@linuxmi:~$ export EDITOR=/usr/bin/gedit Verify with:

linuxmi@linuxmi:~$ export | grep -i EDITOR

4. Export a Function

Use the -f option to export a shell function so that it is available in subshells.

linuxmi@linuxmi:~$ test () { echo "Test Function"; }<br/>linuxmi@linuxmi:~$ export -f test<br/>linuxmi@linuxmi:~$ bash<br/>Test Function

5. Configure Persistent Environment Variables

Append export statements to .bashrc (or another profile file) to make them permanent, for example:

linuxmi@linuxmi:~$ echo export PATH="/snap/bin/lxd:$PATH" >> .bashrc

After the file is sourced, the new path will be applied on every login.

Summary

The Linux export command is a convenient tool for configuring environment parameters. It is easy to learn, offers a few useful options, and can be used to list, set, and export variables and functions, as well as to make persistent changes to the shell environment.