Does Anybody Still Use CL? PDF Print E-mail
Programming - CL
Written by Robert Cozzi   
Tuesday, 03 October 2006 18:00

Recently, I sat down with Greg Veal, author of CL Programming for the AS/400, at the COMMON Conference in Miami Beach and recorded a podcast from the COMMON Expo show floor. We spoke about a number of topics; hear the podcast in its entirety at iSeriesTV.com.

One of the subjects that came up was the recent enhancements to CL. Greg makes several good points about specific enhances in the podcast, but I've since had a few thoughts.

First, CL is in a very poor strategic place. It isn't considered a full-blown application development language, like RPG IV, C++, or Visual Basic, and it isn't considered a great dynamically interpreted scripting language like PHP, Perle, or Python.

Yet we love CL. We love CL and love to hate it. From what I can see, people who develop applications for the iSeries and System i fall into one of several classifications, without any clear winner.

  • Use CL in the traditional sense. Wrap all application calls in it. Perform overrides with it. Do as much as possible in CL.
  • Use CL for job flow control and overrides.
  • Use CL for OPNQRYF and overrides.
  • Use CL for overrides only.
  • Use CL from within RPG IV only when an API isn't available to do the same thing.

It is my belief that there are more iSeries developers out there today who do not know how to write their own CL command definitions than there are those who do. In fact, there may be more people out there programming the iSeries who do not know CL at all than those who do. And I don't mean in North America only. I think if you looked at worldwide figures, I would be proven correct.

But so what? The real question of the day is this: Are CL enhancements important?

At first, I giggled at the notion of enhancements to a language that I virtually no longer use. If I don't use it, "most people" probably don't use it. Right? Of course, this is a stupid assumption on my part. As I've said before, I have a lake in my back yard. All the ducks in the lake are mallards. So does that mean most of the world's ducks are mallards? Of course not.

In my opinion, these CL enhancements are not only nearly two decades late, but critical for the survival of the platform. Why? Because if the platform is to survive, all of its base components need to do everything effectively. This means CL needs to do even more than it does now. For example, launch PHP, interpret JavaScript or PHP, provide full structured-programming constructs (not a subset of them as it currently includes).

Would any of these features cause me to start using CL again? Probably not, but they would allow new developers to adapt to a platform that has been considered "old" for decades.

Yes, the most advanced platform in the world is still considered old by the up-and-coming generation of IT staffers because it does some common, everyday things (such as mail) much more poorly than any other platform. One thing that would surely kill this box is if its flagship programming languages started to get stale. Although CL has been DOA for more than 20 years, it now has new life. We should encourage that and see what wonderful things come from it.

Bob Cozzi is a programmer/consultant, writer/author, and software developer of the RPG xTools, a popular add-on subprocedure library for RPG IV. His book The Modern RPG Language has been the most widely used RPG programming book for nearly two decades. He, along with others, speaks at and runs the highly-popular RPG World conference for RPG programmers.


Robert Cozzi
About the Author:

Bob Cozzi is a programmer/consultant, writer/author, and software developer of the RPG xTools, a popular add-on subprocedure library for RPG IV. His book The Modern RPG Language has been the most widely used RPG programming book for nearly two decades.

 

MC Press books written by Bob Cozzi available now on the MC Press Bookstore.

 

RPG TnT RPG TnT

Jam-packed with an unbelievable number of quick, easy-to-implement RPG tips!
List Price $65.00
Now On Sale
 
The Modern RPG IV Language The Modern RPG IV Language
Cozzi on everything RPG! What more could you want?

List Price $99.95
Now On Sale
 
Read More >>

< Prev   Next >
Last Updated on Tuesday, 03 October 2006 18:00
 
Guest.Visitor
I find it difficult how you can NOT use CL. We are a small group of mainframe Cobol developers, and use CL quite extensively. If you have programs, you have to have CL to invoke/call it. We\'re building a new data center, and will be migrating to a state-of-the-art I5 OS. So for my group, any future enhancements to CL will well be worth it. - Jim P. AS/400 Application Development Team Lead
Guest.Visitor
There are a lot of original programs written in CL that are simply not worth the effort to convert. They do what they do and they do it very well. With the enhancements in RPG it\'s getting much easier to do things like file overrides in RPG but I still go back to the CL when I need to for consistencies sake if nothing else. I definitely see the point about younger developers not knowing CL though. I\'m the oldest developer in our group at 39 and I\'m the only one here who can write a command and am usually consulted by everyone else when they have to create or modify a CL. Even if they are consulting me on it though, they are still using CL.
Guest.Visitor
Not using CL implies more diligent error handling would need to be coded into the application. Now I\'m not saying one should rely completely on CL programs for error handling. But some errors within RPGLE just can\'t be handled without canceling the program unless someone coded every line to have a error handler. Without a CL to fall back on, this may mean cancelling the job. Restarting a job may not be as practical as simply performing a retry on the call to the application.
Guest.Visitor
I really hate it when the cake is on the dinner table and I am expected to eat tasteless steamed vegetable. I know veggies are healthier but you know, cake is tastier. I can indeed master the API calls and do away with using CL altogether, or somewhat. But ... with CL aroud, when will I find time to make the transition? How can a bear learn to hunt food if the picknickers constantly feed them leftovers?
Guest.Visitor
Some things are just easier in CL (i.e. work management). There is online help via F1 rather than going to InfoCenter - although I know you love it :). It\'s easy to test. It\'s easy to prompt via F4 (try prompting an API). Error handling is seamless. It\'s a good scripting/programming language. And here is the problem. It doesn\'t excel in either scripting or programming. We have a number of HLLs available to programmers on iSeries so I think CL shouldn\'t excel in programming. But scripting.... YES it should beat REXX, Perl, PHP or any other scripting language. Enhancements are long overdue.
Guest.Visitor
I would say, I eat, sleep and breath CL for the last 15 years so frankly speaking to me, CL make its presence in OS400 very prominently. Almost all OS400 APIs has a CL wrapper for an OS CL commands. However, its enhancement is not complete yet. IBM need to come up more functionality in term of integration and portability to other programming languages. I\'ll wait for the day when CL will be a TRUE programming language (similar to RPGLE) so that I could update it in my CV.. I\'m still looking for CL to be able to perform update, delete or write data record in files directly rather than just read only. Recent CL enhancements in V5R3 is a eye-opener to other non-CL developers. I hope this is just the begining and more to come in later release. CL is more than 20 years old but still running strong compare to PL/1, REXX in OS400.. Let see what IBM has to say about this..!
David Abramowitz
I first started working with CL on a (very underpowered) beta S/38 model 3 in 1979. Our group had been previously working on a S/34 which used interactive OCL. We learned CL diligently but initially had one problem. No one told us that you had to compile the CL. We spent some time examining the code and couldn\'t figure out what we had done wrong! Eventually we got it. Between CL and database functions we soon realized that the S/38 was really unrelated to the S/34 except by twinax cabling, and the 5250 protocol. For many years, CL provided functionality unmatched by anything else. Dave
nandelin15
RPG is great for database programming, but when it comes to daily operations involving systems components or generating, compiling, packaging, and installing software, how could you live without CL? Shell Scripts? Ant? XML Configuration Files? Talk about going back to the dark ages! Nathan.
Guest.Visitor
In response to "Do we still use CL"....Yes, most definately. I am in a COBOL shop and sometimes writing a short CL program to do a task is much easier. As for Updating and writing to files in CL programs we can do that to with the help of ASC\'s Sequel product(fantastic product). It allows us to do all of the SQL commands you would do in regular SQL and QM(ie. update, insert, delete, create query files). I mean this is really a great pair when used together, you can pass parameters to SEQUEL create your output in a number of different formats and then FTP, EMAIL all from within your CL program. I will be using CL as long as I am in an AS400 shop.
dchristen
I haven’t coded a CL program since collage, 14+ years ago. If there isn\'t an API to do what I need, I use the QCapCmd API to run the appropriate CL Command. I mainly code applications but I spend 10-20% of my time, at work and at home, doing systems administration and have not needed to code a CL Pgm for either discipline. I see from the previous replies that I am in the minority, so I will accept that the improvement to CL’s structure etc… actually are helpful to others, rather than bemoan IBM using resources to improve CL, a dead end language IMO. Duane Christen
Guest.Visitor
The last time I used GOTO was 26 years ago. I then stopped LEAVE, ITER etc. Now I dont even use MOVE. However there are people who demand that GOTOs and MOVE etc be included in /free, and some of them are recognized gurus. There would always be people who refuse to learn new tricks and insist that old tricks be upgraded. I am among one of them. I am too lazy to learn all the APIs and expect IBM to improve the CL.
Guest.Visitor
we run multiple environments via a switching cl that sets up library list, jobd, routing data, etc. I\'m sure you could accomplish this with apis, but - why bother?
don.brown@msd.net.au
Admin/400 can reduce the number of CL programs required to invoke programs and has a heap of other features and it is not expensive. See http://www.msd.net.au/cms/pages/Menu/Applications/Admin400/!/display.html
ACT
CL IS A PART OF INFORMATION TECHNOLOGY THAT OUTLIVED ITS PURPOSE...In the earler 80s, an IBM sales engineer told me that I will never go hungry if I stick with IBM/IT in general and CL/RPG in particular. I made a BIG mistake when I dumped my ORACLE opportunity for this crap.
Ralph Daugherty
[i>CL IS A PART OF INFORMATION TECHNOLOGY THAT OUTLIVED ITS PURPOSE...[/i> If you\'re not any brighter than this, you couldn\'t handle an "ORACLE opportunity" anyway. CL is a job control language used to set up jobs with object allocations and overrides and handle job failure and messaging. Good grief. rd
Guest.Visitor
I think the question could be rephrased "Does anybody still programmatically run commands without calling QCMDEXC?". Yes, I do. I still use CL. Chris
Guest.Visitor
If you only had \'one\' Oracle opportunity.... here, take mine... Its not the language, its the app.
wbois@unifirst.com
Yes, there are a ton of system API\'s that accomplish much of what you can do from a command perspective, but coding a CL program is much easier. I recently tied two vendor product command interfaces together with job scheduling for EDI and FTP processing. Could I have coded it all in an RPGLE program with API\'s, yes, but why would I want to. Again, it all boils down to the right tool for the job. It\'s the environment, stupid! 8>)
Ralph Daugherty
I used bound CLLE modules in an ILE server program, also call CL as standalone programs when needed, seldom use the RPG command call for internal command execution, seems to me mostly for internal library list manipulation, but that\'s when library lists were tight. rd
Guest.Visitor
I completely agree. I think there are very few people like Duane Christen who would compeltely do away with CL. The justification can be to make it portable. Today, RPG has provided many thing like EXTFILE that makes CL unnecessary in many cases. Writing complex programs in CL always sucked for me. However in some of the cases it is very convenient for me to program in CL as you I press F4 and fill in the blanks. I guess I can blame my memory which is fading away with age, and my being in CL for too long.
AVROHOM
So is also IBM commands. Who does not use the command CPYF? Those who do not know how to write their own commands do not know also how to use API programs. To write an API program is much more difficult than writing command definitions.
ACT
"If you only had \'one\' Oracle opportunity.... here, take mine..." You have got got to learn it... If by now you don\'t know that you are sitting in an ORACLE gold mine, the pink slip will come into your way. By the way where are you situated and what is the name of your company so that others who are interested can grab it.
Please login to make comments.
User Rating: / 0
PoorBest 

   MC-STORE.COM