ac(1)
NAME
ac - print statistics about users' connect time
SYNOPSIS
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 ]
DESCRIPTION
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 of zero. 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.
OPTIONS
-d, --daily-totals
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
-p, --individual-totals
Print time totals for each user in addition to the usual
everything-lumped-into-one value. It looks like:
bob 8.06
goff 0.60
maley 7.37
root 0.12
total 16.15
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.
--complain
When the wtmp file has a problem (a time-warp, missing record,
or whatever), print out an appropriate error.
--reboots
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.*
--supplants
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.*
--timewarps
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.*
--compatibility
This is shorthand for typing out the three above options.
-a, --all-days
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
login activity.
--tw-leniency num
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.
--tw-suspicious num
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.
-y, --print-year
Print year when displaying dates.
-z, --print-zeros
If a total for any category (save the grand total) is zero,
print it. The default is to suppress printing.
--debug
Print verbose internal information.
-V, --version
Print the version number of ac to standard output and quit.
-h, --help
Prints the usage string and default locations of system files to
standard output and exits.
FILES
wtmp
The system wide login record file. See wtmp(5) for further
details.
AUTHOR
The GNU accounting utilities were written by Noel Cragg <noel@gnu.ai.mit.edu>. The man page was adapted from the accounting texinfo page by Susan Kleinmann <sgk@sgk.tiac.net>.
SEE ALSO
login(1), wtmp(5), init(8), sa(8) 2010 August 16 AC(1)
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
