gerris path not set?

There is already a script to setup the env. variables. To use it, just call it this way:
\". /opt/setup_env.sh\" (with a space between . and /opt...)

This will setup all the environment variables for gerris, elmer, OpenFOAM etc...
This script is used in root & guest accounts in their special .bashrc-CAE file used by CAE command line tools for these users.

To make CAE-command-line tools work flawlessly with another user profile, you will need to copy /root/.bashrc-CAE in your Home directory.

But at anytime you can run the setup_env.sh script from a shell to do the trick !!