29
Fri, Nov
0 New Articles
  1. You are here:  
  2. Home
  3. IT Infrastructure
  4. System Administration
  5. TechTalk: Using Permanent Work Files

TechTalk: Using Permanent Work Files

Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

Most programmers I've spoken with use QTEMP whenever they need a temporary work file in an application. Why not, after all? QTEMP is meant to be used for temporary stuff anyway. The big advantage of using QTEMP is that it's unique to each job and it's gone as soon as the job ends.

Using QTEMP has one slight disadvantage, however. It requires you to create the file each time you need it. If your work files are flat (without field definitions) and intended to be used as program-described files, that's no hardship. In the AS/400 world, however, most programmers would rather work with externally described files.

This means that you'd have to keep the source DDS for your work files somewhere (and it can't be QTEMP!). If a programmer realizes that those source members have no corresponding objects, the programmer may believe the source code to be obsolete and remove it from the system. Next time you attempt to create the work file in QTEMP, the program fails.

There's a good alternative: create your work files in one of your production libraries (preferably the same library you use for the programs and actual database files), and leave them there, permanently. The work file can have a rich field definition provided by complicated DDS, including references to permanent database files, edit codes, the works. You can even create logical files (even join files) on top of your work files!

This we may call a permanent work file. Because they're not in QTEMP, any job can access them--and this presents a problem since two or more jobs could have a legitimate need to write records to the same work file. How do you tell apart the data from the two jobs? The answer is, fortunately, quite simple: use a different member for each job's data.

It's not hard to do. Your permanent work file must be created with MAXMBRS(*NOMAX) to allow multiple members. Then each time a job needs to write to the file, add a member with the ADDPFM command. When the job is near completion, remove the member with the RMVM command.

Since each member must have a different name, you can name the member as 'JOBnnnnnn' where nnnnnn is the six-character job number--which you can retrieve with the RTVJOBA command, specifying NBR(&JOBNBR). Last, but not least, you must remember to override the permanent work file with the OVRDBF command so that all programs that follow reference the member just added.

It sounds complicated--and it is--but it works more efficiently than using QTEMP. To simplify the task, you can use the Add Work File Member (ADDWRKFMBR) command and the Remove Work File Member (RMVWRKFMBR) command listed in1a and 1b. 1c shows CL program WRKF001CL.

It sounds complicated--and it is--but it works more efficiently than using QTEMP. To simplify the task, you can use the Add Work File Member (ADDWRKFMBR) command and the Remove Work File Member (RMVWRKFMBR) command listed in Figures 1a and 1b. Figure 1c shows CL program WRKF001CL.

Here's an example of how to use it:

ADDWRKFMBR FILE(workfile) OVERRIDE(*YES) CALL PGM(PGM1) CALL PGM(PGM2) RMVWRKFMBR FILE(workfile)

The ADDWRKFMBR command has an optional parameter, RTNMBR, in which you can enter a 10-character CL variable. If used, ADDWRKFMBR returns to the CL variable the name of the member it just added.

TechTalk: Using Permanent Work Files

Figure 1A Command ADDWRKFMBR

 ADDWRKFMBR: CMD PROMPT('Add Work File Member') PARM KWD(FILE) TYPE(Q1) MIN(1) PROMPT('Work file + name') PARM KWD(OVERRIDE) TYPE(*CHAR) LEN(4) RSTD(*YES) + DFT(*YES) VALUES(*YES *NO) + PROMPT('Override to new member') PARM KWD(RTNMBR) TYPE(*CHAR) LEN(10) RTNVAL(*YES) + PMTCTL(*PMTRQS) PROMPT('CL var for new + member (10)') PARM KWD(ACTION) TYPE(*CHAR) LEN(4) CONSTANT(*ADD) Q1: QUAL TYPE(*NAME) LEN(10) MIN(1) QUAL TYPE(*NAME) LEN(10) DFT(*LIBL) + SPCVAL((*LIBL) (*CURLIB)) PROMPT('Library') 
 
 TechTalk: Using Permanent Work Files
 
 Figure 1B Command RMVWRKFMBR
 
 RMVWRKFMBR: CMD PROMPT('Remove Work File Member') PARM KWD(FILE) TYPE(Q1) MIN(1) PROMPT('Work file + name') PARM KWD(OVERRIDE) TYPE(*ZEROELEM) PARM KWD(RTNMBR) TYPE(*ZEROELEM) PARM KWD(ACTION) TYPE(*CHAR) LEN(4) CONSTANT(*RMV) Q1: QUAL TYPE(*NAME) LEN(10) MIN(1) QUAL TYPE(*NAME) LEN(10) DFT(*LIBL) + SPCVAL((*LIBL) (*CURLIB)) PROMPT('Library') 
 
 TechTalk: Using Permanent Work Files
 
 Figure 1C CL program WRKF001CL
 
 WRKF001CL: + PGM PARM(&QFILE &OVERRIDE &RTNMBR &ACTION) DCL VAR(&ACTION) TYPE(*CHAR) LEN(4) DCL VAR(&FILE) TYPE(*CHAR) LEN(10) DCL VAR(&JOBNBR) TYPE(*CHAR) LEN(6) DCL VAR(&LIB) TYPE(*CHAR) LEN(10) DCL VAR(&MBRNAME) TYPE(*CHAR) LEN(10) DCL VAR(&MSGDTA) TYPE(*CHAR) LEN(80) DCL VAR(&MSGF) TYPE(*CHAR) LEN(10) DCL VAR(&MSGFLIB) TYPE(*CHAR) LEN(10) DCL VAR(&MSGID) TYPE(*CHAR) LEN(7) DCL VAR(&OVERRIDE) TYPE(*CHAR) LEN(4) DCL VAR(&QFILE) TYPE(*CHAR) LEN(20) DCL VAR(&RTNMBR) TYPE(*CHAR) LEN(10) MONMSG MSGID(CPF0000) EXEC(GOTO CMDLBL(SNDERRMSG)) /* Determine name of member */ CHGVAR VAR(&FILE) VALUE(%SST(&QFILE 1 10)) CHGVAR VAR(&LIB) VALUE(%SST(&QFILE 11 10)) RTVJOBA NBR(&JOBNBR) CHGVAR VAR(&MBRNAME) VALUE('JOB' *CAT &JOBNBR) CHGVAR VAR(&RTNMBR) VALUE(&MBRNAME) MONMSG MSGID(MCH3601) /* Add or remove member as needed */ IF COND(&ACTION *EQ '*ADD') THEN(ADDPFM FILE(&LIB/&FILE) + MBR(&MBRNAME)) ELSE CMD(RMVM FILE(&LIB/&FILE) MBR(&MBRNAME)) /* Override if necessary */ IF COND(&OVERRIDE *EQ '*YES') THEN(OVRDBF FILE(&FILE) + TOFILE(&LIB/&FILE) MBR(&MBRNAME)) GOTO CMDLBL(ENDPGM) /* Send error message */ SNDERRMSG: + RCVMSG MSGTYPE(*EXCP) MSGDTA(&MSGDTA) MSGID(&MSGID) MSGF(&MSGF) + MSGFLIB(&MSGFLIB) SNDPGMMSG MSGID(&MSGID) MSGF(&MSGFLIB/&MSGF) MSGDTA(&MSGDTA) + MSGTYPE(*ESCAPE) /* End program */ ENDPGM: + ENDPGM
BLOG COMMENTS POWERED BY DISQUS

LATEST COMMENTS

Support MC Press Online

$

Book Reviews

Resource Center

  • SB Profound WC 5536 Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application. You can find Part 1 here. In Part 2 of our free Node.js Webinar Series, Brian May teaches you the different tooling options available for writing code, debugging, and using Git for version control. Brian will briefly discuss the different tools available, and demonstrate his preferred setup for Node development on IBM i or any platform. Attend this webinar to learn:

  • SB Profound WP 5539More than ever, there is a demand for IT to deliver innovation. Your IBM i has been an essential part of your business operations for years. However, your organization may struggle to maintain the current system and implement new projects. The thousands of customers we've worked with and surveyed state that expectations regarding the digital footprint and vision of the company are not aligned with the current IT environment.

  • SB HelpSystems ROBOT Generic IBM announced the E1080 servers using the latest Power10 processor in September 2021. The most powerful processor from IBM to date, Power10 is designed to handle the demands of doing business in today’s high-tech atmosphere, including running cloud applications, supporting big data, and managing AI workloads. But what does Power10 mean for your data center? In this recorded webinar, IBMers Dan Sundt and Dylan Boday join IBM Power Champion Tom Huntington for a discussion on why Power10 technology is the right strategic investment if you run IBM i, AIX, or Linux. In this action-packed hour, Tom will share trends from the IBM i and AIX user communities while Dan and Dylan dive into the tech specs for key hardware, including:

  • Magic MarkTRY the one package that solves all your document design and printing challenges on all your platforms. Produce bar code labels, electronic forms, ad hoc reports, and RFID tags – without programming! MarkMagic is the only document design and print solution that combines report writing, WYSIWYG label and forms design, and conditional printing in one integrated product. Make sure your data survives when catastrophe hits. Request your trial now!  Request Now.

  • SB HelpSystems ROBOT GenericForms of ransomware has been around for over 30 years, and with more and more organizations suffering attacks each year, it continues to endure. What has made ransomware such a durable threat and what is the best way to combat it? In order to prevent ransomware, organizations must first understand how it works.

  • SB HelpSystems ROBOT GenericIT security is a top priority for businesses around the world, but most IBM i pros don’t know where to begin—and most cybersecurity experts don’t know IBM i. In this session, Robin Tatam explores the business impact of lax IBM i security, the top vulnerabilities putting IBM i at risk, and the steps you can take to protect your organization. If you’re looking to avoid unexpected downtime or corrupted data, you don’t want to miss this session.

  • SB HelpSystems ROBOT GenericCan you trust all of your users all of the time? A typical end user receives 16 malicious emails each month, but only 17 percent of these phishing campaigns are reported to IT. Once an attack is underway, most organizations won’t discover the breach until six months later. A staggering amount of damage can occur in that time. Despite these risks, 93 percent of organizations are leaving their IBM i systems vulnerable to cybercrime. In this on-demand webinar, IBM i security experts Robin Tatam and Sandi Moore will reveal:

  • FORTRA Disaster protection is vital to every business. Yet, it often consists of patched together procedures that are prone to error. From automatic backups to data encryption to media management, Robot automates the routine (yet often complex) tasks of iSeries backup and recovery, saving you time and money and making the process safer and more reliable. Automate your backups with the Robot Backup and Recovery Solution. Key features include:

  • FORTRAManaging messages on your IBM i can be more than a full-time job if you have to do it manually. Messages need a response and resources must be monitored—often over multiple systems and across platforms. How can you be sure you won’t miss important system events? Automate your message center with the Robot Message Management Solution. Key features include:

  • FORTRAThe thought of printing, distributing, and storing iSeries reports manually may reduce you to tears. Paper and labor costs associated with report generation can spiral out of control. Mountains of paper threaten to swamp your files. Robot automates report bursting, distribution, bundling, and archiving, and offers secure, selective online report viewing. Manage your reports with the Robot Report Management Solution. Key features include:

  • FORTRAFor over 30 years, Robot has been a leader in systems management for IBM i. With batch job creation and scheduling at its core, the Robot Job Scheduling Solution reduces the opportunity for human error and helps you maintain service levels, automating even the biggest, most complex runbooks. Manage your job schedule with the Robot Job Scheduling Solution. Key features include:

  • LANSA Business users want new applications now. Market and regulatory pressures require faster application updates and delivery into production. Your IBM i developers may be approaching retirement, and you see no sure way to fill their positions with experienced developers. In addition, you may be caught between maintaining your existing applications and the uncertainty of moving to something new.

  • LANSAWhen it comes to creating your business applications, there are hundreds of coding platforms and programming languages to choose from. These options range from very complex traditional programming languages to Low-Code platforms where sometimes no traditional coding experience is needed. Download our whitepaper, The Power of Writing Code in a Low-Code Solution, and:

  • LANSASupply Chain is becoming increasingly complex and unpredictable. From raw materials for manufacturing to food supply chains, the journey from source to production to delivery to consumers is marred with inefficiencies, manual processes, shortages, recalls, counterfeits, and scandals. In this webinar, we discuss how:

  • The MC Resource Centers bring you the widest selection of white papers, trial software, and on-demand webcasts for you to choose from. >> Review the list of White Papers, Trial Software or On-Demand Webcast at the MC Press Resource Center. >> Add the items to yru Cart and complet he checkout process and submit

  • Profound Logic Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application.

  • SB Profound WC 5536Join us for this hour-long webcast that will explore:

  • Fortra IT managers hoping to find new IBM i talent are discovering that the pool of experienced RPG programmers and operators or administrators with intimate knowledge of the operating system and the applications that run on it is small. This begs the question: How will you manage the platform that supports such a big part of your business? This guide offers strategies and software suggestions to help you plan IT staffing and resources and smooth the transition after your AS/400 talent retires. Read on to learn: