/var/log/wtmp
exists,
a record of individual
login and logout times are written to it by
login(1)
and
init(8),
respectively.
The program
ac
examines these
records and writes the accumulated connect time for all logins to the
standard output.
Options available:
/var/log/wtmp
.
If no arguments are given, ac displays the total amount of login time for all active accounts on the system.
The default
wtmp
file is an infinitely increasing file
unless frequently truncated. This is normally
done by the daily daemon scripts scheduled by
cron(8),
which rename and rotate the
wtmp
files before truncating them (and keep about a week's worth on hand).
No login times are collected, however, if the file does not exist.
For example,
ac -p -t "ttyd*" > modems
ac -p -t "!ttyd*" > other
allows times recorded in
modems
to be charged out at a different rate than
other
.
The ac utility exits 0 on success, and >0 if a fatal error occurs.
/var/log/wtmp
/var/log/wtmp.[0-7]
AT&T UNIX
.
This version of
ac
was written for
NetBSD1.0
from the specification provided by various systems' manual pages.