Copy source members to the IFS

Someone asked me how I would write a program to copy all of the members in source files to separate files in the IFS, where they could then me imported into a GiT. I can see a program like this being more useful overtime as more people move from using source files to using a GiT repository.

In this example I will be copying all the source members from the source file DEVSRC in the library MYLIB to the IFS directory /home/MyFolder. The files in the IFS would all be named in the following way: source_member_name.source_member_type, for example: TESTRPG.RPGLE

My first attempt at creating a program to do this was to use RPG. I was going to use the CPYTOIMPF command within the QCMDEXC Scalar function. Alas, several hours of creating program I received the following message when running the RPG program for the first time:

Deleting objects in the IFS with a SQL scalar function

This post is a two-for-one where I will explain how two of the additions that came in the latest Technology Refreshes go together.

The first is a new scalar function IFS_UNLINK, which is found in the SYSTOOLS library, that deletes IFS objects that are passed to it as a parameter. Behind the scenes it calls the unlink() C API. The scalar function returns the integer value that is returned by the C API. If it completed successfully, IFS_UNLINK returns a value of zero. If there was an error the scalar function returns an errno value.

The second addition, ERRNO_INFO, which is also found in the SYSTOOLS library, is a Table function that will return the description of the errno passed to it.

The easiest way I know to be able to show you how it works is to show an example of using it.

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.

Reading a file in the IFS with SQL

One the latest additions to Db2 for i in the latest Technology Refreshes, IBM i 7.4 TR3 and 7.3 TR9, was a Table function offering us the promise of reading a file in the IFS.

In the past I gave an example of how to read a file in the IFS in a RPG program using UNIX-type APIs, but the promise of this Table function makes this new approach look so much easier.

There are three new Table functions that basically do the same thing, which one to use depends upon which format you want the data returned in:

1. IFS_READ:  Returns the data as plain text
2. IFS_READ_UF8:  Returns the data in UTF8 format
3. IFS_READ_BINARY:  Returns the data in a binary string

More SQL Table Functions for interrogating IFS

Last week I started writing about the new table functions introduced in IBM i 7.4 TR1 and 7.3 TR7, describing the first of the four table functions that allow me to retrieve information about IFS directories and files. In this post I will describe the other three:

• IFS_OBJECT_LOCK_INFO
• IFS_JOB_INFO
• IFS_OBJECT_REFERENCES_INFO

 

Using SQL to list directories and files in IFS

Thanks to the folks at RZKH who downloaded and applied the PTFs for IBM i 7.4 TR1 on the first day they became available, what great service!, I have been able to explore some of the new features added to the operating system we know and love. Amongst the additions to Db2 for i, or SQL, is a number of table functions to list information about the directories and files in the Integrated File System, IFS. My original thought was to write one post about them all, but the more I played with the IFS_OBJECT_STATISTICS table function I came to the conclusion that it deserved its own post.

The IFS_OBJECT_STATISTICS table function returns similar information to the RTVDSKINF command. All I want is just some basic information about the directories and files I choose, but there are many more columns returned by the table function. I encourage you to check the link at the bottom of this post which will take you to the appropriate page in IBM's documentation.

In my folder, MyFolder, I have created the following files and subdirectories:

Adding Column Headings to a file in the IFS

In an earlier post I showed how it was possible to copy a file to the IFS in CSV format using CPYTOIMPF command. Unless the recipient of the file knows what the columns are they are going to come back to you asking what they are.

So what can you do to provide column headings?

Email IFS files

The subject matter of this post compliments the previous post Zipping files in the IFS, which describes how to copy a file to the IFS and zip it in preparation for sending it via email.

Until recently it was not possible to email a file from the IFS without using a third party tool or an API. There is the command SNDDST that I have used to send emails from an IBM i (AS400) with the contents of files or files located in the QDLS file system as attachments. But it cannot access the IFS.

A new command SNDSMTPEMM has been introduced, via PTF, to IBM i 6.1 and 7.1 that allows you to email a file from the IFS as an attachment.

Zipping files in the IFS

 

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