Date: Wed, 5 Mar 1997 18:58:20 -0500 (EST) From: I Brake for Moths <[EMAIL PROTECTED]>
Is there a way for a user without root priveleges to cleanly unmount the root file system and shutdown the computer? Yes, they just need to log in and give the three fingered salute, after you give them permission. Here's what you need to know (mostly from 'man shutdown'): Shutdown can be called from init(8) when the magic keys CTRL-ALT-DEL are pressed, by creating an appropriate entry in /etc/inittab (already done for you on most debian systems). To prevent this, shutdown can check to see if an authorized user is logged in on a virtual console (not an X session, mind you). If shutdown is called from init, it checks to see if the file /etc/shutdown.allow is present. It then compares the login names in that file with users logged in on a virtual console (from /var/run/utmp). Only if one of those authorized users or root is logged in, it will proceed. Otherwise it will write the message shutdown: no authorized users logged in to the (physical) system console. The format of /etc/shut- down.allow is one user name per line. Empty lines and com- ment lines (prefixed by a #) are allowed. Currently there is a limit of 32 users in this file. I hope this helps. Happy shutdowning.