osx man page for acct

ACCT(5) 						      BSD File Formats Manual							   ACCT(5)

NAME
     acct -- execution accounting file

SYNOPSIS
     #include <sys/acct.h>

DESCRIPTION
     The kernel maintains the following acct information structure for all processes. If a process terminates, and accounting is enabled, the ker-
     nel calls the acct(2) function call to prepare and append the record to the accounting file.

     /*
      * 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;

     struct acct {
	     char    ac_comm[10];    /* name of command */
	     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;	     /* memory usage average */
	     comp_t  ac_io;	     /* count of IO blocks */
	     dev_t   ac_tty;	     /* controlling tty */
     #define AFORK   0x01	     /* forked but not execed */
     #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

     #ifdef KERNEL
     struct vnode    *acctp;
     #endif

     If a terminated process was created by an execve(2), the name of the executed file (at most ten characters of it) is saved in the field
     ac_comm and its status is saved by setting one of more of the following flags in ac_flag: AFORK, ASU, ACOMPAT, ACORE and ASIG.

SEE ALSO
     lastcomm(1), acct(2), execve(2), accton(8), sa(8)

HISTORY
     A acct file format appeared in Version 7 AT&T UNIX.

BSD
								   June 5, 1993 							       BSD