Comparing differences between objects in two IFS directories

While it has been possible to compare the contents of two directories in the IFS it has not been, well, simple. A new addition to Db2 for i, SQL, in the latest round of Technology Refreshes, IBM i 7.5 TR4 and IBM i 7.4 TR10. Makes it a whole lot, well, easier.

The new SQL Table function, COMPARE_IFS uses the output from the Table functions IFS_OBJECT_STATISTICS and IFS_OBJECT_PRIVILEGES to compare the objects in two IFS directories to one another. It will only check the following object types:

• Character special files, *CHRSF
• Directories, *DIR
• Name pipes, *FIFO
• Local sockets, *SOCKET
• Stream files, *STMF
• Symbolic links, *SYMLNK

I created two subfolders within my home directory, /home/MyDir, called subdir1 and subdir2. I uploaded some files into each one. Some were the same files, others were different files, and some files had the same names but different contents.

RPGPGM.COM-unity in So Cal

Last week I was at OCEAN's TechCon2024 conference, in southern California, and I took the opportunity to hand out some more of the RPGPGM.COM-unity ribbons.

What is the RPGPGM.COM-unity? You will have to click on this link to learn what it means, and who has ribbons.

Now possible to build SQL Alias over last member

The SQL Create Alias statement was enhanced in the latest round of Technology Refreshes, IBM i 7.5 TR4 and IBM i 7.4 TR10. Previously when you created a SQL Alias you had to give a specific member in the DDS Physical file. Now I can use *LAST to denote the most recent member in the Physical file, and what is really cool is if I add another member to the file the Alias will now use that member!

This will be clearer when I show my examples.

First I need a DDS physical file. I called this one MULTIMBR, and it is found in my library MYLIB.

A R RMULTIMBR A FIELD 100A

I compiled the above DDS Physical file with the following command:

01 CRTPF FILE(MYLIB/MULTIMBR) SRCFILE(MYLIB/DEVSRC) MAXMBRS(*NOMAX)

List all object types using SQL

Have you ever wondered how many different types of objects there in IBM i? And what the types of objects are?

The latest Technology Refreshes give us a SQL View that contains that information, and we can query it to answer those questions.

The SQL View is called SYSTEM_OBJECT_TYPES, and it is found in the QSYS2 library. It has three columns:

1. OBJECT_TYPE:  Object type
2. TEXT_DESCRIPTION:  Description of what the object type is
3. CATEGORY:  There are two categories:
   IFS - object is in the IFS
   LIBRARY - object resides in a library (not an IFS object)

New functionality added to RPG's SND-MSG op code

Two years ago the Send Message, SND-MSG, operation code was added to RPG. In the latest round of Technology Refreshes a number of new options have been added to SND-MSG and the Target, %TARGET, built in function.

To oversimplify it SND_MSG consists to three parts:

1. Type of message to send
2. Message text or variable
3. The target for the message, which is the %TARGET built in function, BiF. This is optional

For example:

SND-MSG *INFO 'Message text goes here' %TARGET(*SELF)

Deleting old device definitions

Last month I wrote about a way to list all of the unused virtual devices in your partition. In response to the article I received a question: "Is there a way to then delete these devices, other than manually going through? One system I just did has over 5,000 devices...."

The answer, of course, is yes there is. Before I give my final result let me go through the steps I did to create a SQL script to delete the unused virtual devices.

I can identify the virtual devices using the Object Statistics SQL Table function. I do not want to repeat myself. For the details read my previous article.

I decide to create a Common Table Expression, CTE, as it was just "neater". In the first part of the statement I would create a virtual table of all the eligible virtual devices, and in the second I would delete them. To start with I just want to make sure I gather the data I expected, therefore, my first statement did not do any deleting.

Constant keyword added to RPG definitions

As part of the latest Technology Refreshes, IBM i 7.5 TR4 and 7.4 TR10, comes an addition to the variable and data structure definitions. It is now possible to use the constant keyword as part of those definitions to protect them from being changed.

Why would I want to do that?

There are times I want to use a variable, rather than a constant. It might be to contain a date. I would not want this to be changed, either on purpose or by accident.

Below is an example:

01 **free 02 dcl-s StartDate date inz(*sys) const ; 03 dsply StartDate ; 04 StartDate = d'2024-07-04' ;