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.\"     @(#)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 $
.\" $DragonFly: src/share/man/man5/acct.5,v 1.3 2007/11/23 23:03:57 swildner 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 AXSIG .
.Sh SEE ALSO
.Xr acct 2 ,
.Xr execve 2 ,
.Xr sa 8
.Sh HISTORY
A
.Nm
file format appeared in
.At v7 .