allow a user to run command as another user without any password prompt

Question

I'm trying to achieve same result as the answer from that existing SF question without having to enter the password for the original user, that is, I'm userA, and I want to be able to run a command as userB without having to enter the passwords for any of these users.

Can somehow provide an example to assist me please?

Answer 1

Just add a NOPASSWD tag. So, using the example in the previous question, you would do:

tom  ALL=(oracle) NOPASSWD: /bin/chown tom *