Subject: Re: Question about rwho (oh, you already know?)
To: Stephen M. Jones <>
From: Johnny Billquist <>
List: tech-net
Date: 01/09/2003 01:02:26
On Wed, 8 Jan 2003, Stephen M. Jones wrote:

> rwho has an issue with reporting the number of users on a system 
> acurately.. basically, once you have 41 or more users on a system,
> rwho will report no more.  Is there a hack around this?  I almost
> always have more than 41 people on my machines and I would like to
> see rwho get 'fixed' .. I've submitted a pr on formating (when a
> machine has been up over 100 days, ruptime -a needed frobbing) that
> was an easy enough fix, but increasing the number of users it will
> report requires more work.
> Does this have to do with the number of 'ttys' rwho knows about rather
> than just MAXUSERS = 42 ? 

The limit 42 comes from the fact that users are listed in an array which
is 1024/sizeof(whoent) entries. sizeof(whoent) is 24, and 1024/24 is 42.6.
It's probably not a difficult thing to just change the size of this array,
but some other systems might not show entries after the 42:nd, might
crash, might be just happy, or who knows...? (see the man-page for rwhod
for the format of the message). rwho broadcast the message over UDP, but I
don't think that fragmenting the message should be a problem, but that too
might be an issue.

There is also currently a bug in rwhod, which basically means that users
will only be included in the first packet sent out after they log in, and
then they "disappear". I have a fix for that locally here, but am not
really sure if it should be fixed the way I did it.


Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email:           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol