Enable to user to run program as root, but disable to user to modify it.

stenedjo

Requirements are

1. The user root can modify program.
2. The user usr can not modify program even if the user is in root group.
3. The user usr can run program as root without password even if the user is not in root group.

How?

jbalamtlf

assuming the program is owned by root, you just need to set the suid bit with chmod, i believe 4755 is the appropriate mode for what you describe.