Some of us have, literally for decades, been dealing with wtmp by rolling it weekly or monthly or quarterly or whatever, letting cron run something like cd /usr/adm # that's how long I've been doing this! umask 022 ln wtmp wtmp.prev mv wtmp.new wtmp # also so long ago there was no seq(1) nums=`awk 'BEGIN {for (i = 12; i >= 0; i--) print i; exit}'` for i in $nums; do inext=`expr $i + 1` if [ -f wtmp.$i ]; then mv wtmp.$i wtmp.$inext fi done mv wtmp.prev wtmp.0 This really isn't rocket science. It isn't even particularly interesting UNIX history. Can we move on to something that IS interesting? Here are some things I find more interesting: 1. utmp came before wtmp: utmp(V) appears in the First Edition manual, wtmp(V) only in the Second. Apparently interest in who else is logged in right now predated interest in who has logged in recently. 2. Both files started out in /tmp. wtmp is first said to be in /usr/adm instead in the Fifth Edition manual, utmp in /etc in the Sixth. 3. The names /tmp/utmp and /tmp/wtmp appear to have been issued by the Department of Redundancy Department. I think it quite likely that Ken and Dennis would have been familiar with that joke once the recording containing it was issued in mid-1970, but I don't know whether utmp existed in some form before that. I see no sign of it in the fragments of PDP-7 source code we have (in particular init doesn't seem to use it), but what about later PDP-7 or very early PDP-11 code predating the late-1971 First Edition manual? Norman Wilson Toronto ON Not Insane