Path: utzoo!utgpu!watmath!clyde!att!rutgers!deimos!uxc!uwmcsd1!marque!uunet!seismo!esosun!ucsdhub!isg100!elgar!ag
From: ag@elgar.UUCP (Keith Gabryelski)
Newsgroups: comp.unix.wizards
Subject: Re: Autologout of unused terminals
Message-ID: <20@elgar.UUCP>
Date: 1 Dec 88 04:40:01 GMT
References: <74@attibr.UUCP> <3603@jpl-devvax.JPL.NASA.GOV>
Reply-To: ag@elgar.UUCP (Keith Gabryelski)
Organization: Elgar Corporation, San Diego, CA
Lines: 44

In article <74@attibr.UUCP> vch@attibr.UUCP (Vincent C. Hatem) writes:
>You could also use 'who -u' (on Sys V), which tells the idle time...

Idle time messages on some versions of system V who are broken.  They
use st_mtime instead of st_atime.  From `man stat':

sed -n "s/(S)/(2)/gp" 				# if appropriate.

	  st_atime   Time when file data was last accessed.  Changed
		     by	the following system calls: creat(S),
		     mknod(S), pipe(S),	utime(S), and read(S).
						      ^^^^^^^

	  st_mtime  Time when data was last modified.  Changed by the
		    following system calls: creat(S), mknod(S),
		    pipe(S), utime(S), and write(S).
					   ^^^^^^^^
The idle daemon code is trivial (written during halftime on Monday).
If anyone would like a copy, send me mail.

In article <3603@jpl-devvax.JPL.NASA.GOV> lwall@jpl-devvax.jpl.nasa.gov
(Larry Wall) brings up:
>[...] but idle-killers are so easy to spoof, unless you disable
>people from executing utime() or ioctl().

The daemon code, IMHO, should not be intended for use against
malicious(*) or unwilling idlers.  The code is used to logout users
who forget to logout.

Also, an idle daemon may not be appropriate for some (even most)
sites, but it is a valid option for a few.  You don't even have to be
fascist about the code, set it for three hours if you like ... with
warning messages.

(*) ``malicious idlers'' here is defined as a user that hogs a
terminal (by being logged in) for an usually long period of time
without using the terminal.

nohup(1) is a viable alternative in a lot of the idle terminal cases.

Pax, Keith

-- 
ag@elgar.CTS.COM         Keith Gabryelski          ...!{ucsd, jack}!elgar!ag