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.
acac 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.
acctonlastcommlast, you can search the
acct file for a particular user, terminal, or command.
saacct 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.
dump-acctdump-utmpacct and utmp files in a human-readable format.
For more detailed information on any of these programs, check the chapter with the program title.
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.
The detailed format of the acct file written by the Linux kernel
varies depending on the kernel's version and configuration:
Linux kernels 2.6.7 and earlier write a v0 format acct file
which unfortunately cannot store user and group ids (uid/gid)
larger than 65535.
Kernels 2.6.8 and later write the acct file in v1, v2 or v3 formats.
(v3 if BSD_PROCESS_ACCT_V3 is selected in the kernel configuration,
otherwise v1 if on the m68k architecture or v2 everywhere else).
Since version 6.4 the GNU accounting utilities on Linux systems are
able to read all of the v0, v2 and v3 file formats (v1 is not supported).
Thus you do not need to worry about the details given above. You can even
read acct files where different records were written by differently
configured kernels (you can find out about the format of each entry by
using the dump-acct utility). In case you ever need to convert
an acct file to a different format, the --raw option of
dump-acct does that together with the new --format and
--byteswap options that determine format and byte order of the
output file.
Multiformat support under Linux is intended to be a temporary solution
to aid in switching to the v3 acct file format. So do not expect
GNU acct 6.7 to still contain Multiformat support. In a few years
time, when everybody uses the v3 format, the ability to read multiple
formats at runtime will probably be dropped again from the GNU accounting
utilities.
This does not, however, affect the ability to adapt to the acct file
format at compile time (when ./configure is run). Even GNU acct 6.3.5
(that does not know about multiple file formats) will yield working binary
programs when compiled under a (as yet hypothetical) Linux kernel 2.6.62
that is only able to write the v3 format.
I don't have any idea who originally wrote these utilities. If anybody
does, please send some mail to noel@gnu.ai.mit.edu 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 <ericb@lsid.hp.com>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 <bad@flatlin.ka.sub.org>Michael Calwas <calwas@ttd.teradyne.com>Derek Clegg <dclegg@apple.com>Alan Cox <iiitac@pyr.swan.ac.uk>Scott Crosby <root@hypercube.res.cmu.edu>--sort-real-time for sa.
Solar Designer <solar@false.com>--ahz flag in lastcomm and sa.
Dirk Eddelbuettel <edd@miles.econ.queensu.ca>Jason Grant <jamalcol@pc-5530.bc.rogers.wave.ca>sa.
Kaveh R. Ghazi <ghazi@caip.rutgers.edu>Susan Kleinmann <sgk@sgk.tiac.net>Alexander Kourakos <Alexander@Kourakos.com>--wide option for last.
Marek Michalkiewicz <marekm@i17linuxb.ists.pwr.wroc.pl>--ip-address flag for last.
David S. Miller <davem@caip.rutgers.edu>Walter Mueller <walt@pi4.informatik.uni-mannheim.de>Ian Murdock <imurdock@gnu.ai.mit.edu>Tuomo Pyhala <tuomo@lesti.kpnet.fi>--strict-match flag in lastcomm.
Tim Schmielau <tim@physik3.uni-rostock.de>Luc I. Suryo <root@patriots.nl.mugnet.org>--user flag for lastcomm.
Pedro A M Vazquez <vazquez@iqm.unicamp.br>Marco van Wieringen <Marco.van.Wieringen@mcs.nl.mugnet.org>