Environment variables

Print all environment variables

printenv

Print an environment variable

echo $VAR

Create or set an environment variable (only for the current session)

VAR="value"
export VAR

Remove an environment variable (only for the current session)

unset VAR

To expand the $PATH environment variable permanently you can put the following line into $HOME/.profile

export PATH=$PATH:/new/path

To activate this setting run

. $HOME/.profile