acct(4)acct(4)NAMEacct - per-process accounting file format
SYNOPSIS
#include <sys/types.h>
#include <sys/acct.h>
DESCRIPTION
Files produced as a result of calling acct(2) have records in the form
defined by sys/acct.h, whose contents are:
typedef ushort_t comp_t; /* "floating point" */
/* 13-bit fraction, 3-bit exponent */
struct acct
{
char ac_flag; /* Accounting flag */
char ac_stat; /* Exit status */
uid_t ac_uid; /* Accounting user ID */
gid_t ac_gid; /* Accounting group ID */
dev_t ac_tty; /* control typewriter */
time_t ac_btime; /* Beginning time */
comp_t ac_utime; /* acctng user time in clock ticks */
comp_t ac_stime; /* acctng system time in clock ticks */
comp_t ac_etime; /* acctng elapsed time in clock ticks */
comp_t ac_mem; /* memory usage in clicks */
comp_t ac_io; /* chars trnsfrd by read/write */
comp_t ac_rw; /* number of block reads/writes */
char ac_comm[8]; /* command name */
};
#define AFORK 01 /* has executed fork, but no exec */
#define ASU 02 /* used super-user privileges */
#define ACCTF 0300 /* record type: 00 = acct */
#define AEXPND 040 /* Expanded Record Type*/
In ac_flag, the AFORK flag is turned on by each fork and turned off by an
exec. The ac_comm field is inherited from the parent process and is
reset by any exec. Each time the system charges the process with a clock
tick, it also adds to ac_mem the current resident process size (see ps(1)
for a description of resident size). This consists of all valid pages
for a process, regardless of sharing.
The value of ac_mem/(ac_stime+ac_utime) can be viewed as an approximation
to the mean process size.
The structure tacct, which resides with the source files of the
accounting commands, represents the total accounting format used by the
various accounting commands:
/*
* total accounting (for acct period), also for day
*/
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acct(4)acct(4)
struct tacct {
uid_t ta_uid; /* userid */
char ta_name[8]; /* login name */
float ta_cpu[2]; /* cum. cpu time, p/np (mins) */
float ta_kcore[2]; /* cum kcore-minutes, p/np */
float ta_con[2]; /* cum. connect time, p/np, mins */
float ta_du; /* cum. disk usage */
long ta_pc; /* count of processes */
unsigned short ta_sc; /* count of login sessions */
unsigned short ta_dc; /* count of disk samples */
unsigned short ta_fee; /* fee for special services */
};
REFERENCESacct(1M), acct(2), acctcom(1), exec(2), fork(2)NOTICES
The ac_mem value for a short-lived command gives little information about
the actual size of the command, because ac_mem may be incremented while a
different command (for example, the shell) is being executed by the
process.
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