01 - Programming (EN)


Last Updated on 7 June 2020 by Roberto De Pedrini

It is the question I always ask my fellow programmers when they ask me something: “Have you read the manual?”.

We know, RPG programmers are very lazy, most of them go on with those four instructions learned 30 years ago: CHAIN, MOVE, EXFMT and WRITE. All jobs in the I.T. sector have a very high rate of obsolescence and it is unthinkable to be able to make an entire working career without studying, learning and using new techniques and to do it there are different ways: there are – for example – FAQ400 courses, articles published on specialized sites and – above all – the manuals. When I happen to have intense development days I always keep RPG and SQL manuals open on the desktop of my PC and I often find something new that is right for me.

The last episode that happened to me was about the CLEAR operating code: what will there ever be to learn about an operating code that has existed for centuries? I was investigating a malfunction in a program and at some point I came to the conclusion that a multiple structure, used in a multiple FETCH, remained inexplicably dirty from the previous round despite there being a CLEAR before the FETCH (I simplified it a bit). I imagine that all of you who are reading have already understood what the error was, but I did not perceive it and only reading the RPG manual I discovered that to clean all the occurrences of a multiple structure it is necessary to do “CLEAR * ALL multiple-structure”: I did not know. What do I mean by that? That even the oldest and most trivial operating codes have options, added by IBM over the years, unknown to us and if we never open the manual they remain unknown. I understand that it is more convenient and easier to ask someone better than us, but no one – however good – can replace the manual and this applies to any programming language.

So, in summary:

  1. RPG and SQL manual always open on the desktop.
  2. Browser with an open tab on the IBM knowledge center site.
  3. LPEX editor online help: position the cursor on an operating code, on a built-in function, on a keyword and press F1 (the first time is slow).
  4. When you have a free bream open the RPG or SQL manual and scroll through the list of operating codes and functions: you will find a lot of interesting new things.

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IBM i software developer

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