This is explained in the Installation tutorial, section 1.6 - Environment setup (here from the Jade tutorial):
It's convenient if the ROS environment variables are automatically added to your bash session every time a new shell is launched:
echo "source /opt/ros/jade/setup.bash" >> ~/.bashrc
source ~/.bashrc
Note also the warning:
If you have more than one ROS distribution installed, ~/.bashrc
must only source the setup.bash
for the version you are currently using.
If you just want to change the environment of your current shell, you can type:
source /opt/ros/jade/setup.bash
Btw: source
ing is never 'permanent'. It will always only update the shell in which it was invoked.