shutdown
 

/sbin/shutdown file has "rx" permissions to group and others also, then why can't it allow regular users to shutdown the system

Put the users in /etc/shutdown.allow -- *nix commands that modify system state (such as changing IP addresses and the like) won't work for normal users, even if they can access the commands, because the kernel puts in checks. The /etc/shutdown.allow file allows users listed in there to short-circuit that (not sure the exact method).

or you could have a look at "sudo"

caid