The List Data Areas (LSTDTAARA) command produces a list of all data areas in a library, revealing their contents. Optionally, it can list only those data areas that contain a given character string.
The other day, while rereading “Now What? What to Do When a Programmer Leaves” (MC, January 1998), I saw a potential security risk. Suppose a programmer hardcodes his user profile name within a CL program so that only he can access certain privileged functions of the program. Or perhaps the programmer is clever and softcodes his name within a data area.
If the name is hardcoded, a simple run of the Find String with PDM (FNDSTRPDM) command can pinpoint the source code of the programs in question. But if the name is softcoded, you don’t have a prayer of finding out—unless you have something like my List Data Areas (LSTDTAARA) command. Or suppose you know that a data area in QSYS contains the string V04R02M00, but you can’t remember its name. LSTDTAARA can help you there, too. Just download the code from the MC Web site (http://www.midrangecomputing.com/mc/98/11), and you’re on your way.
LSTDTAARA prints a list of all character data areas in a given library. Besides printing the name of the data area, LSTDTAARA lists the data area’s entire contents, up to the last nonblank character. But that’s not all LSTDTAARA can do; you can supply an optional character string for LSTDTAARA to find. In that case, the report lists only those character data areas that contain the string you specified.
For instance, let’s say you suspect a programmer has softcoded his user profile name, HERVE, in some data area of library ACCTG. To find out if that’s indeed the case, run the following command:
LSTDTAARA LIB(ACCTG) STRING(HERVE)
The LSTDTAARA command has rather simple code. Its CPP, CL program DTA002CL, simply produces a database file with one data area per record, courtesy of the Display Object Description (DSPOBJD) command. The outfile is named DTAARA and placed in QTEMP. Then, it calls RPG III program DTA002RG to generate the listing.
Since the outfile produced by DSPOBJD is defined using QSYS/QADSPOBJ as a model, I coded the RPG III program with QADSPOBJ in the F-spec. Consequently, the CL program needs a way to tie QADSPOBJ (in the RPG III program) to the QTEMP/DTAARA file (they are, actually, one and the same thing). That’s done by using the Override with Database File (OVRDBF) command before calling the RPG program and the Delete Override (DLTOVR) command afterward.
The RPG program begins by calculating the length of the character string you have supplied, and it places that length in field LEN. To calculate the length, it uses the CHEKR op code with a single blank character in Factor 1. Then, it enters a loop in which it reads one record from QADSPOBJ (i.e., one data area name) and calls CL program DTA003CL to retrieve the value of the data area. If DTA003CL cannot retrieve the value, field RTNCDE has a value of *ON. This error condition may occur if the data area is not of type character, for example, or if it was deleted between the moment DSPOBJD generated the outfile and the moment the RPG program reached the record in QADSPOBJ containing the name of the data area.
If the retrieval is successful, the program prints the data area name and contents if
(a) you specified no string to scan, or (b) you did and the string is contained anywhere within the data area.
The actual printing is performed in subroutine PRINT. The subroutine begins by printing a NEWDA record, which writes the name of the data area to the printer and does not advance the paper. Next, it enters a loop, extracting 100 characters at a time and printing that, this time advancing the paper. The result is that only the first 100 characters of the data area value are printed on the same physical line as the data area name. After printing each 100-character chunk, the subroutine finds out if the rest of the data area is all blanks. If it is, the subroutine exits the loop. It also exits the loop whenever the next 100 characters are beyond the 2,000-character mark, which is the maximum length of a character data area.
DTA002RG has one more trick you may want to use in your RPG III programs. You know that RPG IV has the D-specs in which you can define every single field, data structure, array, and table of your program. In an RPG IV program, therefore, you can gather all field definitions and put them in the same place so they aren’t scattered all over the C-specs as definitions of result fields. RPG III doesn’t have D-specs or anything like that, but you can “fake” them with a subroutine that does nothing but define the fields.
That subroutine is named DCLVAR (for “declare variables”) in my RPG III programs. Within that subroutine, I code a Z-ADD for numeric fields and a MOVE for alpha fields, initializing the fields to zeros or blanks, respectively. Furthermore, the lines within DCLVAR are sorted alphabetically by field name. And if too many fields share the same characteristics (for instance, many fields represent object names), first I define a pseudo-data-type field such as NAME (as 10 bytes), and then I define all the actual fields by referencing NAME, using the *LIKE DEFN op code. It works like a charm.
Code for this article on the Web at http://www.midrangecomputing.com/mc/98/11
More 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.
TRY 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.
Forms 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.
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:
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.
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:
LATEST COMMENTS
MC Press Online