hostname & system-specific .bashrc

[andreagalle]

Finding alternatives to $HOSTNAME var to customise the env. Useful links:

• https://www.redhat.com/sysadmin/linux-environment-variables
• https://unix.stackexchange.com/questions/356253/alternative-to-hostname-for-system-specific-bashrc
• https://superuser.com/questions/412384/different-bashrc-files-for-different-login-nodes
• https://www.2daygeek.com/10-methods-to-check-view-the-hostname-in-linux/
• https://stackoverflow.com/questions/25230805/how-to-detect-which-server-i-am-using-in-bash-profile-and-apply-settings-accord