Using the Accounting History File (ACC)

An account in the SYSTEM Dictionary called ACC contains an Accounting History file also called ACC. This file contains information about activity on a given account. This file contains two types of items:

Items for all users who are currently logged on to the system. These items are automatically created when users log on; they are deleted when users log off. Use the LISTU command to list all active user items.
Accounting history items that keep track of system usage for accounts or users whose Account Definition item or User-ID contains a U in line 9. Use the LISTACC command to display or print an accounting history report. You can also generate accounting history reports using INFO/ACCESS statements.

The accounting history items are useful for system security purposes because they keep track of the following information for each account or user:

Process number
Time and date of each logon and logoff
Length of time the account or user is connected
Number of CPU units used
Number of pages sent to Spooler

The item-IDs are the user-ID or account name concatenated with the number of the process used for the session. In the example, user SMYTHE has two items in the Accounting History file, one for process 0 and one for process 2. This is an example of an accounting history report:

>LISTACC

PAGE 1			10:51:49 DD MMM YYYY

ACC......	DATE...	TIME....	CONN..	UNITS...	PAGES
		*	*	*	*
JOHN#0	12/20	16:38	00:02	100
	12/22	13:59	01:04	1
SMYTHE#0	12/16	12:43	00:00	7
		12:44	00:00	10
		12:45	00:02	11
		12:47	00:00	1
		12:47	00:00	4
	12/19	08:43	01:01	1
		14:35	00:00	2
		14:37	02:09	100
	12/20	08:48	02:50	60
	12/22	08:26	01:01	1
	12/23	08:10	01:02	1
		14:09	00:10	1
SMYTHE#2	12/16	11:22	02:09	29
		15:24	70:07	82
	12/19	13:47	01:01	10
	12/20	09:38	01:00	2

Active User Items

Active user items in the ACC file are constructed as follows:

Item-ID	Hexadecimal frame ID of the process’s Primary Control Block (PCB). PCBs start at 1024 (X’0400’), so the entry for a user on process 0 will have an item-ID of 0400. Since each process requires 32 frames of workspace, the entry for a user on process 1 will have an item-ID of 0420 (decimal 1056), and so on.
Line 1	NAME	Contains the name of the user or account.
Line 2	DATE	Contains the date the user or account logged on.
Line 3	TIME	Contains the time the user or account logged on.

This is a table of process numbers and their active user item-IDs:

Process	Item-ID
0	0400
1	0420
2	0440
3	0460
4	0480
5	04A0
6	04C0
7	04E0
8	0500
9	0520
10	0540
11	0560
12	0580
13	05A0
14	05C0
15	05E0

Accounting History Items

Accounting History items are updated when a user or an account logs off. Lines 1, 2, and 3 are not used for Accounting History items. Accounting History items are constructed as follows:

Line 4	DATE	Contains an entry for each date the user or account logged on. If multiple logoffs occur on the same date, the dates are stored as MultiValues for LIST alignment. Dates are stored in internal format.
Line 5	TIME	Contains an entry for each time the user or account logged on. Time is stored in internal format.
Line 6	UNITS	Contains the number of units of CPU usage for each session.
Line 7	CONN	Contains the time in seconds between logon and logoff.
Line 8	PAGES	Contains the number of pages sent to the printer for each session.

Lines 4 through 8 are stored as a controlling- dependent data set, with line 4 being the controlling value and lines 5 through 8 the dependent values. The table below gives a summary of both the active user items and the accounting history items in the ACC file.

Line	Attribute Name	Active Users	Accounting History
0	item-ID	hexadecimal PCB frame ID	user-ID#process account#process
1	name	user name account name	not used
2	name	date logged on	not used
3	time	time logged on	not used
4	date		dates logged on
5	time		times logged on
6	units		charge units
7	conn		connect time
8	pages		number of printer pages generated

Clearing the ACC File

Periodically it will be necessary to clear the accounting history items from the ACC file to prevent it from filling up its allotted space. First select the accounting history items only, then delete them:

>SELECT ACC WITH NO NAME

>DELETE ACC