How to Use the Linux export Command

Environment variables

An environment variable is a named value that programs can read, such as PATH or HOME. A normal shell variable exists only in the current shell. export marks a variable so that every program started from this shell can also see it.

Basic use

export variable_name=value

Example:

export MY_NAME="John"

Do not put spaces around =.

Read the variable

echo $MY_NAME

Export a function (Bash)

function name() {
  echo "Hello, $MY_NAME!"
}
export -f name

View all exported variables

export

You can also use export -p or printenv.

Remove a variable

unset MY_NAME

Common uses

1. Add a folder to PATH, the list of folders searched for commands:

export PATH=$PATH:/path/to/bin

1. Set language and locale:

export LANG=en_US.UTF-8
export LC_ALL=en_US.UTF-8

1. Give settings to scripts:

export DATABASE_HOST=localhost
export DATABASE_USER=myuser

1. Set a shell alias. This is not an export, but it is often put in the same file:

alias ll='ls -la'

Make it permanent

An exported variable lasts only for the current session. To keep it, add the line to a startup file:

• ~/.bashrc for your interactive shells.
• ~/.profile for login shells.
• /etc/environment for all users (plain NAME=value lines, no export).

Then reload the file:

source ~/.bashrc

Quick recap

• export NAME=value shares a variable with child programs.
• unset NAME removes it.
• Add it to ~/.bashrc to keep it after logout.