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Copyright (C) 1993, 1996, 1997 Free Software Foundation, Inc.

Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies.

Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one.

Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that this permission notice may be stated in a translation approved by the Foundation.


Way back a long time ago, Thompson and Ritchie were sitting opposite one another at the commissary, sipping coffees and discussing their evolving behemoth.

"This behemoth of ours," said Ken, "is becoming rather popular, wouldn't you say?" "Yes," said Dennis. "Every time I want to do a compilation, I have to wait for hours and hours. It's infuriating." They both agreed that the load on their system was too great. Both sighed, picked up their mugs, and went back to the workbench. Little did they know that an upper-management type was sitting just within earshot of their conversation.

"We are AT&T Bell Laboratories, aren't we?" the upper-management type thought to himself. "Well, what is our organization best known for?" The brill-cream in his hair glistened. "Screwing people out of lots of money, of course! If there were some way that we could keep tabs on users and charge them through the nose for their CPU time..."

The accounting utilities were born.

Seriously though, the accouting utilities can provide a system administrator with useful information about system usage--connections, programs executed, and utilization of system resources.

Information about users--their connect time, location, programs executed, and the like--is automatically recored in files by init and login. Four of them are of interest to us: wtmp, which has records for each login and logout; acct, which records each command that was run; usracct and savacct, which contain summaries of the information in acct by user and command, respectively. Each of the accounting utilities reports or summarizes information stored in these files.

prints statistics about users' connect time. ac can tell you how long a particular user or group of users were connected to your system, printing totals by day or for all of the entries in the wtmp file.
turns accounting on or off.
lists the logins on the system, most recent first. With last, you can search the wtmp file for a particular user or terminal name (to which the user was connected). Of special interest are two fake users, `reboot' and `shutdown', which are recorded when the system is shut down or reboots.
lists the commands executed on the system, most recent first, showing the run state of each command. With last, you can search the acct file for a particular user, terminal, or command.
summarizes the information in the acct file into the savacct and usracct file. It also generates reports about commands, giving the number of invocations, cpu time used, average core usage, etc.
display acct and utmp files in a human-readable format.

For more detailed information on any of these programs, check the chapter with the program title.

A Note on File Names and Locations

The wtmp and acct files seem to live in different places and have different names for every variant of u*x that exists. The name wtmp seems to be standard for the login accounting file, but the process accounting file might be acct or pacct on your system. To find the actual locations and names of these files on your system, specify the --help flag to any of the programs in this package and the information will dumped to standard output.

Regardless of the names and locations of files on your system, this manual will refer to the login accounting file as wtmp and the process accounting files as acct, savacct, and usracct.

History of the Accounting Utilities

I don't have any idea who originally wrote these utilities. If anybody does, please send some mail to [email protected] and I'll add your information here!

Since the first alpha versions of this software in late 1993, many people have contributed to the package. They are (in alphabetical order):

Eric Backus <[email protected]>
Suggested fixes for HP-UX 9.05 using /bin/cc: configure assumed you were using gcc and tacked on -Wall etc. He also noticed that file_rd.c was doing pointer arithmetic on a void * pointer (non-ANSI).
Christoph Badura <[email protected]>
Christoph was a BIG HELP in computing statistics, most notably k*sec stuff! He also did Xenix testing and contributed some Makefile fixes and output optimizations.
Michael Calwas <[email protected]>
Fixed bugs in mktime.c.
Alan Cox <[email protected]>
Original Linux kernel accounting patches.
Scott Crosby <[email protected]>
Suggested idea behind --sort-real-time for sa.
Solar Designer <[email protected]>
Fixed off-by one error in allocations in sa.
Dirk Eddelbuettel <[email protected]>
Managed bug-fixes & etc. for Debian distribution, as well as the architect of merge of GNU + Debian distributions. A big thanks to Dirk for kicking me back into gear again after a long period of no work on this project.
Jason Grant <[email protected]>
Identified a buffer-overrun bug in sa.
Kaveh R. Ghazi <[email protected]>
Tested the package on many systems with compilers other than gcc. Fixed K&R C support.
Susan Kleinmann <[email protected]>
Contributed excellent man pages!
Marek Michalkiewicz <[email protected]>
Suggested the --ip-address flag for last.
David S. Miller <[email protected]>
Noticed missing GNU-standard makefile rules.
Walter Mueller <[email protected]>
Noticed install target was missing, and corrected a typo for prefix in Makefile.in.
Ian Murdock <[email protected]>
Tracked down miscellaneous bugs in sa.c under Linux. Added Debian package maintenance files.
Luc I. Suryo <[email protected]>
Suggested the --user flag for lastcomm.
Pedro A M Vazquez <[email protected]>
Fixed bugs in sa.c and tested under FreeBSD.
Marco van Wieringen <[email protected]>
Modified (wrote?) Linux kernel accounting patches.

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