How to run rails s -p80 on 80 port?

Question

By default,

 rails s #running on 3000 port

Now I want to run it on port 80. So I tried:

 sudo rails -s -p80

Answer 1

If you are using RVM, and you did the default setup, then you shouldn't use sudo.

Just:

mlzboy@mlzboy-MacBook ~/my/b2c2 $ rails server -p 80

However 80 is a privileged port, so you need to run as root, and you will have follow the instructions for Multi-User installation of RVM.