.\" Copyright (c) 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)acct.5	8.1 (Berkeley) 6/5/93
.\" $FreeBSD: src/share/man/man5/acct.5,v 1.7.2.2 2001/12/17 11:30:13 ru Exp $
.\"
.Dd June 5, 1993
.Dt ACCT 5
.Os
.Sh NAME
.Nm acct
.Nd execution accounting file
.Sh SYNOPSIS
.In sys/types.h
.In sys/acct.h
.Sh DESCRIPTION
The kernel maintains the following
.Fa acct
information structure for all
processes.
If a process terminates, and accounting is enabled,
the kernel calls the
.Xr acct 2
function call to prepare and append the record
to the accounting file.
.Bd -literal
/*
 * Accounting structures; these use a comp_t type which is a 3 bits base 8
 * exponent, 13 bit fraction ``floating point'' number.  Units are 1/AHZ
 * seconds.
 */
typedef u_short comp_t;

#define AC_COMM_LEN 16
struct acct {
	char	ac_comm[AC_COMM_LEN];  /* command name */
	comp_t	ac_utime;	/* user time */
	comp_t	ac_stime;	/* system time */
	comp_t	ac_etime;	/* elapsed time */
	time_t	ac_btime;	/* starting time */
	uid_t	ac_uid;		/* user id */
	gid_t	ac_gid;		/* group id */
	short	ac_mem;		/* average memory usage */
	comp_t	ac_io;		/* count of IO blocks */
	dev_t	ac_tty;		/* controlling tty */
#define	AFORK	0x01		/* forked but not exec'ed */
#define	ASU	0x02		/* used super-user permissions */
#define	ACOMPAT	0x04		/* used compatibility mode */
#define	ACORE	0x08		/* dumped core */
#define	AXSIG	0x10		/* killed by a signal */
	char	ac_flag;	/* accounting flags */
};

/*
 * 1/AHZ is the granularity of the data encoded in the comp_t fields.
 * This is not necessarily equal to hz.
 */
#define	AHZ	64
.Ed
.Pp
If a terminated process was created by an
.Xr execve 2 ,
the name of the executed file (at most ten characters of it)
is saved in the field
.Fa ac_comm
and its status is saved by setting one of more of the following flags in
.Fa ac_flag :
.Dv AFORK ,
.Dv ASU ,
.Dv ACOMPAT ,
.Dv ACORE
and
.Dv ASIG .
.Sh SEE ALSO
.Xr acct 2 ,
.Xr execve 2 ,
.Xr sa 8
.Sh HISTORY
A
.Nm
file format appeared in
.At v7 .