ac - print statistics about users' connect time
ac [ -d | --daily-totals ] [ -y | --print-year ]
[ -p | --individual-totals ] [ people ]
[ -f | --file filename ] [ -a | --all-days ]
[ --complain ] [ --reboots ] [ --supplants ]
[ --timewarps ] [ --compatibility ]
[ --tw-leniency num ] [ --tw-suspicious num ]
[ -z | --print-zeros ] [ --debug ]
[ -V | --version ] [ -h | --help ]
ac prints out a report of connect time (in hours) based on the
logins/logouts in the current wtmp file. A total is also printed out.
The accounting file wtmp is maintained by init(8) and login(1).
Neither ac nor login creates the wtmp if it doesn't exist, no
accounting is done. To begin accounting, create the file with a length
NOTE: The wtmp file can get really big, really fast. You might want
to trim it every once and a while.
GNU ac works nearly the same u*x ac, though it's a little smarter in
several ways. You should therefore expect differences in the output of
GNU ac and the output of ac's on other systems. Use the command info
accounting to get additional information.
Print totals for each day rather than just one big total at the
end. The output looks like this:
Jul 3 total 1.17
Jul 4 total 2.10
Jul 5 total 8.23
Jul 6 total 2.10
Jul 7 total 0.30
Print time totals for each user in addition to the usual
everything-lumped-into-one value. It looks like:
people Print out the sum total of the connect time used by all of the
users included in people. Note that people is a space separated
list of valid user names; wildcards are not allowed.
-f, --file filename
Read from the file filename instead of the system's wtmp file.
When the wtmp file has a problem (a time-warp, missing record,
or whatever), print out an appropriate error.
Reboot records are NOT written at the time of a reboot, but when
the system restarts; therefore, it is impossible to know exactly
when the reboot occurred. Users may have been logged into the
system at the time of the reboot, and many ac's automatically
count the time between the login and the reboot record against
the user (even though all of that time shouldn't be, perhaps, if
the system is down for a long time, for instance). If you want
to count this time, include the flag. *For vanilla ac
compatibility, include this flag.*
Sometimes, a logout record is not written for a specific
terminal, so the time that the last user accrued cannot be
calculated. If you want to include the time from the user's
login to the next login on the terminal (though probably
incorrect), include this you want to include the time from the
user's login to the next login on the terminal (though probably
incorrect), include this flag. *For vanilla ac compatibility,
include this flag.*
Sometimes, entries in a wtmp file will suddenly jump back into
the past without a clock change record occurring. It is
impossible to know how long a user was logged in when this
occurs. If you want to count the time between the login and the
time warp against the user, include this flag. *For vanilla ac
compatibility, include this flag.*
This is shorthand for typing out the three above options.
If we're printing daily totals, print a record for every day
instead of skipping intervening days where there is no login
activity. Without this flag, time accrued during those
intervening days gets listed under the next day where there is
Set the time warp leniency to num seconds. Records in wtmp
files might be slightly out of order (most notably when two
logins occur within a one-second period - the second one gets
written first). By default, this value is set to 60. If the
program notices this problem, time is not assigned to users
unless the --timewarps flag is used.
Set the time warp suspicious value to num seconds. If two
records in the wtmp file are farther than this number of seconds
apart, there is a problem with the wtmp file (or your machine
hasn't been used in a year). If the program notices this
problem, time is not assigned to users unless the --timewarps
flag is used.
Print year when displaying dates.
If a total for any category (save the grand total) is zero,
print it. The default is to suppress printing.
Print verbose internal information.
Print the version number of ac to standard output and quit.
Prints the usage string and default locations of system files to
standard output and exits.
The system wide login record file. See wtmp(5) for further
The GNU accounting utilities were written by Noel Cragg
<email@example.com>. The man page was adapted from the accounting
texinfo page by Susan Kleinmann <firstname.lastname@example.org>.
login(1), wtmp(5), init(8), sa(8)
1995 October 31