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.\" @(#)acct.5 8.1 (Berkeley) 6/5/93
.\" $FreeBSD$
.\"
.Dd February 13, 2017
.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
#define AC_COMM_LEN 16
/*
* Accounting structure version 3 (current).
* The first byte is always zero.
* Time units are microseconds.
*/
struct acctv3 {
uint8_t ac_zero; /* zero identifies new version */
uint8_t ac_version; /* record version number */
uint16_t ac_len; /* record length */
char ac_comm[AC_COMM_LEN]; /* command name */
float ac_utime; /* user time */
float ac_stime; /* system time */
float ac_etime; /* elapsed time */
time_t ac_btime; /* starting time */
uid_t ac_uid; /* user id */
gid_t ac_gid; /* group id */
float ac_mem; /* average memory usage */
float ac_io; /* count of IO blocks */
__dev_t ac_tty; /* controlling tty */
uint16_t ac_len2; /* record length */
union {
uint32_t ac_align; /* force v1 compatible alignment */
#define AFORK 0x01 /* forked but not exec'ed */
/* ASU is no longer supported */
#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 */
#define ANVER 0x20 /* new record version */
uint8_t ac_flag; /* accounting flags */
} ac_trailer;
#define ac_flagx ac_trailer.ac_flag
};
.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 ACOMPAT ,
.Dv ACORE
and
.Dv ASIG .
.Dv ASU
is no longer supported.
.Dv ANVER
is always set in the above structure.
.Sh SEE ALSO
.Xr lastcomm 1 ,
.Xr acct 2 ,
.Xr execve 2 ,
.Xr sa 8
.Sh HISTORY
A
.Nm
file format appeared in
.At v7 .
The current record format was introduced on May 2007.
It is backwards compatible with the previous format,
which is still documented in
.In sys/acct.h
and supported by
.Xr lastcomm 1
and
.Xr sa 8 .
