A tool that controls the check-out and check-in of production library members to a development library

A Data Processing Manager needs to control the way in which the programming staff makes modifications to the system's library members. I don't say this because I believe the staff will necessarily do anything destructive on purpose. It is just that establishing a method of control can provide benefits to the entire department in terms of audit trails, archives, and the crucial ability to "back-out" adverse program changes.

Among the gems found in the AS/400 QUSRTOOL library is a set of commands, known as the Source Control function, that will act as a librarian of sorts, allowing your staff to check out and return source members from your libraries in an orderly fashion. When a member is checked out, it is copied to a work library for modifications. As with a book in a public library, only one programmer can have a member checked out at one time. Once checked back in to the original library, it is available for another programmer. Source Control records each movement of the library's source members in a log file and provides a display of the history, with the date, time, user, program name and description, and user.

One of the more powerful features of the librarian is that it archives each source member to a file before it is checked out. These past versions remain available until you run a command to purge old versions and their log entries. The beauty of this feature is that you can easily restore any source member to any previous version on file. This is terrific if you find that a program no longer works properly after a change has been made. You can just "back-out" the changes to the last production version until you determine what the problem with the new version is.

The system is voluntary. Even if a library is secured from direct editing, a programmer can still CPYF the source member to another library, work on it, and then copy it back. But the check-out and check-in commands are so easy to use, there is no reason for your staff to voice any objections.

Setting Up the Commands

As we mentioned, this system is part of the QUSRTOOL library, which includes more than 80 (more in Release 2.0) useful application development and system management tools. (For a complete description on this special library, see "Free AS/400 System Management Tools -- Compliments of IBM," DataNetwork (now Midrange Computing), May 1989, or your AS/400, S/38, or S/36 ResourceLibrary.)

QUSRTOOL only contains the source code for each of its tools. The objects must be compiled into a library named TAATOOL. I am not going to go into too much detail on the library in this article, but give just enough instruction to create the Source Control commands. Key the commands shown in 1 to create the TAATOOL library, the CRTTAATOOL command (necessary to create a tool), the prerequisite tools, and the Source Control tool. You'll need Security Officer authority to run CRTTAATOOL.

QUSRTOOL only contains the source code for each of its tools. The objects must be compiled into a library named TAATOOL. I am not going to go into too much detail on the library in this article, but give just enough instruction to create the Source Control commands. Key the commands shown in Figure 1 to create the TAATOOL library, the CRTTAATOOL command (necessary to create a tool), the prerequisite tools, and the Source Control tool. You'll need Security Officer authority to run CRTTAATOOL.

After When you are throw with the commands in 1, you need to manually key in the member type for each member in source file SRCTYP in the TAATOOL library. Make each member type the same name as the member name. These are members that are part of the ADDSRCMBR tools created in the first CRTTAATOOL command from 1.

After When you are throw with the commands in Figure 1, you need to manually key in the member type for each member in source file SRCTYP in the TAATOOL library. Make each member type the same name as the member name. These are members that are part of the ADDSRCMBR tools created in the first CRTTAATOOL command from Figure 1.

Setting Up the Files

Source Control uses three files -- SRCMSTP, SRCAUDP, and SRCDTLP. These are, respectively, the master file with one record per controlled member, the audit file with one record per event, and the archived source members before each change. The last CRTTAATOOL command in 1 created these files in the CRTFILLIB library. Copy these files to each library you will control.

Source Control uses three files -- SRCMSTP, SRCAUDP, and SRCDTLP. These are, respectively, the master file with one record per controlled member, the audit file with one record per event, and the archived source members before each change. The last CRTTAATOOL command in Figure 1 created these files in the CRTFILLIB library. Copy these files to each library you will control.

Using the Commands

There are five commands that are provided:

CHKSRCOUT (Check Source Out): When a programmer wishes to work on a member from a controlled library, CHKSRCOUT is used to copy the source member to a work library. 2 shows the prompt screen. A logical lock is then placed on the member to prevent another programmer from checking out the member.

CHKSRCOUT (Check Source Out): When a programmer wishes to work on a member from a controlled library, CHKSRCOUT is used to copy the source member to a work library. Figure 2 shows the prompt screen. A logical lock is then placed on the member to prevent another programmer from checking out the member.

CHKSRCIN (Check Source In): The programmer uses this to place a previously checked-out member, or any member, into the controlled library. See 3.

CHKSRCIN (Check Source In): The programmer uses this to place a previously checked-out member, or any member, into the controlled library. See Figure 3.

Be aware that this command moves only the source member back to the controlled library. You must move the compiled object back yourself, or compile it again in the controlled library.

MTNSRCCTL (Maintain Source Control): Initializes or refreshes the SRCMSTP file. It also provides options to clean out old entries from SRCAUDP and SRCDTLP files.

RTVSRCCTL (Retrieve Source Control): Retrieves a previous version from the SRCDTLP archive file.

DSPSRCCTL (Display Source Control): Used to review the audit trail of changes to source members. Members can also be retrieved using this display. See 4.

DSPSRCCTL (Display Source Control): Used to review the audit trail of changes to source members. Members can also be retrieved using this display. See Figure 4.

If you do not like the way the commands are set up, you can easily change them since the source for all QUSRTOOL members is provided.

Adding Security

Implementing security will make Source Control more workable. You should change the authorization of the source files you plan to control to allow anyone to read or copy members, but not make changes. You can do this by specifying *USE to *PUBLIC on the EDTOBJAUT command. This will prevent programmers from making changes directly in the controlled source file, causing them to use Source Control. Of course, anyone could sidestep Source Control by copying the member out themselves. But, the purpose of Source Control is not concerned so much with security as it is with providing a controlled development environment.

By default, any user can use the check in/out functions. You can control who is allowed to do this. A data area named SRCCTL is created with public authority in each library that has a SRCMSTP file. You can revoke public authority to this object and authorize individual users to the data area with *USE authority.

More Details

I have given you enough to get you up and running with Source Control. For more details on the various functions, and the uses of all the command parameters, see the SRCCTL member in the QATTINFO file of library QUSRTOOL.

AS/400 Source Librarian

Figure 1 Creating the commands and programs

 Creating the Commands and Programs CRTLIB LIB(TAATOOL) CRTCLPGM PGM(TAATOOL/TAATOLAC) SRCFILE(QUSRTOOL/QATTCL) CALL PGM(TAATOOL/TAATOLAC) CRTTAATOOL TOOL(ADDSRCMBR) CRTTAATOOL TOOL(CHKDBF) CRTTAATOOL TOOL(CHKUSRAUT) CRTTAATOOL TOOL(CVTBIN4DEC) CRTTAATOOL TOOL(EDTVAR) CRTTAATOOL TOOL(PMTOPR) CRTTAATOOL TOOL(RTVMBRD) CRTTAATOOL TOOL(SRCCTL) CRTFILLIB(desired library to control) 
 
 AS/400 Source Librarian
 
 Figure 2 Checking source out
 
 Checking Source Out CHKSRCOUT Check source out Type choices, press Enter. Source file name in SRCMSTP . . CTLFILE Library name . . . . . . . . . *LIBL Member name in SRCMSTP . . . . . CTLMBR To source file name . . . . . . TOFILE *FROMFILE Library name . . . . . . . . . *LIBL To member . . . . . . . . . . . TOMBR *FROMMBR Source control library . . . . . SRCCTLLIB *LIBL Bottom F3=Exit F4=List F5=Refresh F11=Choices F12=Previous F13=How to use this display /ef /bf 3 Checking source in Checking Source In CHKSRCIN Check source in Type choices, press Enter. From source file name . . . . . FROMFILE Library name . . . . . . . . . *LIBL From member . . . . . . . . . . FROMMBR Source file name in SRCMSTP . . CTLFILE *FROMFILE Library name . . . . . . . . . *LIBL Member name in SRCMSTP . . . . . CTLMBR *FROMMBR Option . . . . . . . . . . . . . OPTION *REPLACE Text to describe the change . . CHGTXT Source control library . . . . . SRCCTLLIB *LIBL Remove member in FROMFILE . . . RMVM *YES Bottom F3=Exit F4=List F5=Refresh F11=Choices F12=Previous F13=How to use this display /ef /bf 4 Displaying Source Control audit records Displaying Source Control Audit Records DISPLAY SOURCE CONTROL AUDIT RECORDS Type options, press Enter. 8=Attributes 9=Retrieve source Opt Library File Member Type Actn Date User SSLIB QRPGSRC MST 891128 RICHARD SSLIB QRPGSRC SS010 RPG OUT 891205 RICHARD SSLIB QRPGSRC SS010 RPG RPL 891205 RICHARD SSLIB QRPGSRC SS010 RPG OUT 891206 RICHARD SSLIB QRPGSRC SS010 RPG RPL 891206 RICHARD SSLIB QRPGSRC SS100 RPG OUT 891128 RICHARD SSLIB QRPGSRC SS100 RPG RPL 891128 RICHARD SSLIB QRPGSRC SS100 RPG OUT 891128 MARK SSLIB QRPGSRC SS100 RPG RPL 891205 MARK SSLIB QRPGSRC SS212 RPG OUT 891205 RICHARD SSLIB QRPGSRC SS212 RPG RPL 891205 RICHARD F3=Exit