"no namelist"???

[Richard Todd]

alexis at panix.uucp (Alexis Rosen) writes:

>All of a sudden, for no particular reason, "w" and "lav" are giving me grief.
>They both respond "no namelist" when I try to use them. If I su to root, w
>works, but lav doesn't.

  Hmm, sounds like a certain file has some permission problems.  See below.

>The man pages are singularly unhelpful, and the only file that w seems to
>want is /etc/utmp, which is world-readable and writeable. Recreating utmp
>as an empty file had no beneficial effect.
  The man page for w is obviously lying, since it desparately needs one other
file in order for it to be possible to do what w does--see below.  

>So, what's a namelist, and can I pick one up at the five & dime?

  A namelist is a list of names :-).  Seriously, it's a list of names and 
addresses found in an object file.  In particular, for any program doing
"system-status" stuff like w or lav, the namelist on /unix is very very 
important, since it allows such programs to find out the addresses in 
kernel memory of interesting data structures (like avenrun[], the array that
holds the load averages!) and thus to read the right bit of kernel memory.  
So to run programs that grovel thru kernel innards gleaning valuable 
information, the file /unix needs to be readable.  From the symptoms you
give, and from what the permissions lav and w run under, I'd say that you've
got /unix readable only by root.  Make it world-readable and your problems
should go away.  (The reason you had w working as root but not lav is that
lav is setuid bin (hence running under uid bin, not root), but w is only
setgid sys.  Don't ask me why the permissions are different on the two--there's
no obvious reason why they should be....)
--
Richard Todd	rmtodd at uokmax.ecn.uoknor.edu  rmtodd at chinet.chi.il.us
	rmtodd at servalan.uucp