One of the great things about coding RPG programs in free-format is the pure fact that the rigid spacing requirements of RPG are gone. This fact, however, can make reading a free-format RPG program difficult, especially when your program contains multiple levels of nested IF and/or DO conditions.

Wouldn't it be great to have a utility that would take "dirty" free-format RPG code and clean it up? This TechTip will add the Indent Free-Form ILE RPG (INDFREERPG) tool to your programming toolbox.

Before we look at the INDFREERPG utility, let's look at the problem it will help you resolve. Figure 1 is a code snippet from a free-format RPG program gone amuck.

Figure 1: This code snippet illustrates a "dirty" free-format program.

A program coded like this, while completely acceptable to the compiler, will be difficult to follow when modification or analysis is required later. This program desperately needs a more structured layout. To accomplish this, the INDFREERPG utility takes free-format RPG statements and automatically indents the source statements.

This utility is made up of the following three objects:

1. FDN001RG--ILE RPG program that indents free-format RPG source
2. FDN001CL--CL driver program for FDN001RG
3. INDFREERPG--OS/400 command source for the INDFREERPG command

FDN001RG (Figure 2) examines the specified source physical file member and looks for certain opcodes to determine whether any line should be indented further than the current source indentation.

Figure 2: This program indents a free-format ILE RPG program.

This program reads through the specified source member until it hits a source record containing the /FREE compiler directive. A flag is used to identify that the source after the compile directive is free-format. At that point, the program continues reading through the source member, identifying grouped operations, and indenting the code inside of those operations.

The table below shows a list of these group operations.

If the line becomes too long (greater than 80 characters) as a result of a line of code being indented, the program automatically breaks the code into multiple lines of code that honor the new indentation. The resulting statements are initially loaded into an array and the "new" program is output at the end of the program. This array is currently limited to 32,767 statements. Create this program using the CRTBNDRPG command:

To control the execution of this program, the CL program FDN001CL (Figure 3) is used.

Figure 3: This CL controls the execution of FDN001RG.

Create this program using the CRTCLPGM command:

The primary function of this program is to perform error checking on the parameters supplied by the INDFREERPG command, to prepare the work files used by the application, and finally to create the new source member from these work files.

The source for the INDFREERPG command is shown in Figure 4.

Figure 4: This source is used to create the INDFREERPG command.

Use the CRTCMD command to build the INDFREERPG command:

Once this statement has been executed, the INDFREERPG command is ready to go. This command accepts parameters that define the input source file and member, the output source file and member, the number of characters to indent at each group, and whether or not to replace an existing source member.

Figure 5 shows the prompt screen from this command.

Figure 5: This is the prompt screen for INDFREERPG. (Click image to enlarge.)

This screen illustrates the parameters for the INDFREERPG command. The first set of parameters defines the input source member to be indented. The next parameter defines the number of characters to indent each grouping. A value between 1 and 4 is acceptable for this command. The next set of parameters defines the output file. Optionally, a value of *INFILE, *INLIB, or *INMBR can be used to identify that the output file/library and member are the same as the input file/library and member. The final parameter defines whether or not an existing member should be replaced when the command is executed. If *NO is specified and the output member exists, an error is returned.

Assuming that the free-format RPG shown in Figure 1 was contained in an RPG source member named FRE001RG, the following command would be used to indent the source:

When this statement is executed, the source member is read in and processed by the INDFREERPG command and saved into its original source file member.

Figure 6 shows the source from Figure 1 after is has been processed through INDFREERPG.

Figure 6: The free-format code has been "cleaned up."

As you can see, this version of the code is easier to read and follow. The flow of the program is easy to recognize at a glance. This command works best with applications written using all free-format code.

INDFREERPG can really help to keep your code "free" but under control.

Mike Faust is an Application Programmer for Fidelity Integrated Financial Solutions in Maitland, Florida. He is also the author or The iSeries and AS/400 Programmer's Guide to Cool Things, Active Server Pages Primer, and SQL Built-in Functions and Stored Procedures. You can contact Mike at This email address is being protected from spambots. You need JavaScript enabled to view it..