Lookup IP address host using SQL

Added as part of the recent Technology Refreshes, IBM i 7.5 TR2 and 7.4 TR8, is a new scalar function that returns the hostname for an IP address.

The syntax for this scalar function, DNS_LOOKUP_IP, is simple, and can be used in one of two ways:

01 VALUES DNS_LOOKUP_IP(IP_ADDRESS => '123.456.789.12') ; 02 VALUES DNS_LOOKUP_IP('123.456.789.12') ;

Service extension for old releases of IBM i

I am grateful to the person who sent me the link to the IBM Support document "Service Extension for IBM i 7.3, 7.2, and 7.1", dated July 10, 2023.

I am not going to repeat what the document says, I will provide a link to it below.

The last dates that you can have support for these old releases is:

Use new RPG BiFs to see if input parameter was passed

I cannot remember how long ago it was when IBM introduced the %PARMS RPG Built in Function, BiF, that would return the number of parameters were passed to the program. This has been "refined" in IBM i 7.5 TR2 and 7.2 TR8 with two new BiFs:

• %PASSED:  Returns logical true if the parameter was passed
• %OMITTED:  Returns logical true if the parameter was omitted

To show how these BiFs work I created a procedure, that contains the new, and a RPG program to call the procedure.

Let me start showing by showing the procedure, Procedure:

Using SQL to get Network Attributes

This new View, NEWORK_ATTRIBUTE_INFO, was introduced as part of IBM i TR2 and 7.4 TR8. It shows the same information as the Display Network Attributes command, DSPNETA, and allows you to retrieve the same information as you would using the Retrieve Network Attributes command, RTVNETA.

I will admit I don't use this information much, in fact the only attribute I use is the Current System name. In a CL program I retrieve it using RTVNETA:

01 DCL VAR(&SYSNAME) TYPE(*CHAR) LEN(10) 02 RTVNETA SYSNAME(&SYSNAME)

Finding which fields were defined using a reference field

In my opinion one of the best things about the DDS database is the use of Reference fields. I can define a field in a one file, a "Reference file", and then use it to define fields in other files. These fields will inherit the properties of the "Reference field".

If I need to make a change to the database, changing the size on one field, I can compile all the files that use the "Reference field" and the change will made to the file.

But how can I know which files use a particular "Reference field"?

Fortunately a SQL View gives me the information I need to do this.

Changes to the RPG Select operation code

In my RPG work I have been using the IF-ELSEIF operations code instead of Select groups for longer than I have been writing this web site. I preferred them as I could do the same as a Select operation code in less lines of code.

But then comes along two new RPG operation codes in the latest Technology Refreshes, IBM i 7.5 TR2 and 7.4 TR8, that are related to the Select operation code that might change my mind.

The two new RPG operation codes are:

• WHEN-IS:  Used to compare the given value is equal to a value or variable
• WHEN-IN:  Used to compare the given value is in a list or values, array, or in a range

Copying multiple IFS files into one output file

This us another post that came from a question I was asked by a reader of this blog. The question is:

I have multiple files in an IFS folder with similar names, each has a timestamp at the end of the file name to make them unique. How can I read all the files and write the contents into one file?

Fortunately there are two SQL Table Functions that can help me do this:

• IFS_OBJECT_STATISTICS:  To make a list of the files
• IFS_READ:  Read the contents of the files

The rest is pretty straightforward SQL and RPG.

35th anniversary of IBM i

There has been lots of publicity in the build up to today, and I thought I would add my thoughts on the 35th anniversary of IBM i. That is a little misnomer as the server that was launched on June 21, 1988, was called AS/400, IBM Application System/400, which ran the OS/400, Operating System/400, operating system. Over the intervening years both the server and the operating system have been enhanced to be so much more than AS/400 / OS/400, becoming a thoroughly modern server, IBM Power, and operating system, IBM i.

As this is an anniversary I am not going to talk about the future of IBM Power and IBM i, which is "golden", I am going to write about the history of this.

Getting Save File information with SQL

Added to our SQL "toolkit" with the latest round of Technology Refreshes, IBM i 7.5 TR2 and 7.4 TR8, were two Views and a Table function that helps me get information about Save Files, and their contents.

Prior to these if I wanted to know how many save files I have in my library I would use the Work Object PDM command, WRKOBJPDM:

WRKOBJPDM LIB(MYLIB) OBJTYPE(*FILE) OBJATR(*SAVF)

RPG %SPLIT now handles blank sub-strings

When it was introduced in IBM i 7.4 I thought the Split built in function, BiF, would be useful way to break apart a string into pieces. The one frustration I had with it was when two separators were next to one another %SPLIT would not regard it as an empty, or null, sub-string.

Let me jump straight into my RPG program to demonstrate how this works. Let me start with all the definitions, etc.

01 **free 02 dcl-s String varchar(100) inz('RED,,BLUE,,GREEN,,,BLACK') ; 03 dcl-s Piece char(10) ; 04 dcl-s Array char(10) dim(*auto:999) ;

It has been a decade!

Saturday was the tenth year anniversary of this web site. IMHO that is a remarkable milestone. I have seen other IBM i related web sites and YouTube channels come and go in that time, as people do not appreciate the effort it takes to research, write, and publish content on a regular basis. I am not sure how long I thought I would write, I guess it was until there was nothing more about IBM i to write about. Fortunately IBM has obliged and this decade has seen more additions and changes to our favorite operating system than any other. Long may it continue.

Mass insert into IFS file using IFS_WRITE

There are times when someone asks me a question I think is interesting enough to become a post here. This was the question that was the germ for this post:

How can I read a physical file and for each records, use the IFS_WRITE Function to write the [ IFS ] file?

The IFS_WRITE are really three SQL procedures that writes data to a file in the IFS:

1. IFS_WRITE:  Write plain text to IFS file
2. IFS_WRITE_UTF8:  Write UTF8 text
3. IFS_WRITE_BINARY:  Write binary text

In the following examples I am going to use IFS_WRITE_UTF8 as I want the contents of the IFS file to be UTF8 compatible.