How to set a permanent environment variable? [duplicate]

I am not yet a Linux guy and I have some problem trying to add a new permanent environment variable.

So I have to set a new environment variable named CATALINA_HOME with this value: /opt/apache-tomcat-8.0.23

What can I do to set it permanently?

Tnx


Add the following to the /etc/profile file (for system wide change) or to ~/.profile for local user.

export CATALINA_HOME=/opt/apache-tomcat-8.0.23