Linux: make shutdown not executable for safety

Solution 1:

Completely another aproach how to be warned that you work on productional machine is to mark the terminal. For example the user@machine:~# text could be red at production machines, green at development, etc. Here is nice tutorial how to do this: Color Bash Prompt

Solution 2:

The best advice I can give you is don't login as root unless you need root access, and make sure you have a different root/sudo password on each machine.

Making shutdown inaccessible is one option but it's not a good one. Either alias shutdown to shutdown -a and touch /etc/shutdown.allow or chmod a-x /sbin/shutdown

Also, where does it end? Are you going to also disallow halt, reboot and init?