Trim in CL and its Second Parameter

I am sure I am not the only person who has been using the Trim built in functions (BIFs) in their RPG code to remove leading and trailing blanks from strings. Trim BIFs were introduced into CL with IBM i release 7.1, and function in the same way as their RPG brethren.

Were you aware that the Trim BIFs have a second parameter that can be used for removing characters other than blanks? I have Miguel Cordova to thank for bringing this to my attention. Using the second parameter I can remove any character using the Trim. Below I will show examples in RPG and in CL, and discuss what I found in using them in both languages.

Which Control options/H-specs do you use?

In my many years of experience working for various companies I have found that just a few programmers define Control specifications in their RPG programs. The Control specification is commonly known as the Header specification, or H-spec, as in fixed format RPG the specification character, in the sixth position of the line, is 'H'. In all free RPG the Control specification was replaced by the Control options, 'CTL-OPT'.

In my opinion this was the most cryptic of the specifications in RPG III as you had to know what each column stood for, as it would only reveal its meaning when F4 was pressed to prompt the line.

Happy 2015

I have always found New Years exciting, a new year is ahead of me that will be full of exciting new things and adventures. It is also the chance to bid farewell to the old year, and revisit its highlights.

2014 was an exciting year in the IBM i world with the following:

Display release of IBM i

One of the first things I do when I first signon to an IBM i is to check what release of operating system it is running. Armed with that information I then know what version programming tools and language features I will need to use.

Fortunately there is a quick way and a not so quick way, that takes just a few more key strokes.

Operating systems release history

Server name	Operating system	Release	Available date	End of Support date
AS400 (Application System/400, 1988-2000)	OS400 (1988-2006)	Rel 1	August 26, 1988	?
		R01M00	?	?
		R01M01	?	?
		R01M02	November 25, 1988	?
		R01M03	?	?
		V2R1	May 24, 1991	June 30, 1994

Getting field definitions using SYSCOLUMNS

In several previous posts where I have used the DSPFFD command, see here and here, or the QUSLFLD API, see here, to retrieve the Column Heading of fields in a file someone has commented that I should retrieve the column headings using the SYSCOLUMNS file. In the scenarios described in those post using SYSCOLUMNS would not have worked as it only contains data for files not in QTEMP.

SYSCOLUMNS resides in the library QSYS2, and is a SQL view built over the physical file QABDIFLD. It contains the field/column information for all the files and tables in every library on your IBM i, except those in QTEMP. I am not going to list all the columns in SYSCOLUMNS as the IBM documentation does a good job doing it here.

I am going to show two scenarios how I could use SYSCOLUMNS:

1. List all of the fields in a file.
2. List all the occurrences of a field name in all the files in a library.

Using aliases can be simple

The discussion of whether to use the alias names for files’ fields has become a lengthy here amongst the programming staff. The major argument against has been that there does not appear to be an easy way to perform input or output to record formats in display and printer files. I needed to find a simpler way to define the alias and its uses.

Fortunately IBM came to my aid with PTFs to make the using of alias simple in IBM i 7.1 and 7.2. In my opinion this is the way alias handling should have been from the start.

Node.js now available

Node.js was promised as part of Technical Refresh 9 for IBM i 7.1 and TR1 for 7.2. It was released yesterday, December 15 2014, as a new License Program Option.

Node.js is an open source runtime environment for server side and network applications. Its applications are written in JavaScript using Google's V8 JavaScript engine to execute code. Its runtime can execute on OS X, Microsoft, Free BSD, Linux (which can be hosted on a PowerSystems server along with IBM i) and now IBM i.

User Group: COMMON Luxembourg

I have added a link to COMMON Luxembourg’s website to this site's IBM i user groups page.

Their site is at www.common.lu (you do need the www)

If you know of a user group that is not listed on the user groups page please use the Contact form, on right, to send me its details.

IBM i 7.2 Redbook is out

After being teased last week with a video of Steve Will, Chief Architect for the IBM i, talking about IBM i 7.2 and TR1 the first Redbook for 7.2 was been released yesterday afternoon.

It can be download from IBM's Redbook website here (17.3 MB).

It has chapters covering the following subjects:

1. Introduction to IBM i 7.2
2. Systems management
3. Cloud and virtualization
4. Security
5. Networking
6. High availability
7. Backup and recovery
8. IBM DB2 for i
9. Application development
10. IBM i server functionality

At 416 pages it is going to take a lot of bedtime reading to get through it.

Quick way to find if PTF present and applied

I often need to find out if a particular PTF has been applied to the IBM i I work upon. Most of the time I can use the DSPPTF command to display the PTFs, but there is one instance of IBM i I am not authorized to that command. I think the head IBM i operator is tired of receiving emails from me asking him to check if a certain PTF has been loaded and applied. I needed to find another way I could display a PTF and whether it had been applied on my own.

Fortunately there is a SQL view I can search for this information. According to the IBM documentation this view has been available since IBM i 6.1. The only servers I have access to are running 7.1 and 7.2, so I cannot vouch for whether this will work in 6.1.

Replacing text in a string

I received a request from the engineers: One solvent they use has been place on the "restricted list" by the state and could no longer be used. Could I create a program to replace the solvent's code in their files with the replacement solvent's code?

It gave me a reason to use the %SCANRPL, 'Scan and replace character', built in function that was introduced in IBM i 7.1, and made me think how this could be accomplished with earlier releases too.