String Parameters of Various Lengths

June 19, 2002 Timothy Prickett Morgan

Hey, Ted:

In the May 29 issue of Midrange Guru, OS/400 Edition, you describe a method for passing string parameters of variable length to a subprocedure. This possibility has some risks.

The subprocedure must guarantee that it only changes the data passed to it by the caller.

For example, suppose a parameter field in the called program or procedure is defined with a length of 15 bytes. A calling procedure passes five bytes. The API CEEDOD determines a length of five bytes, which is correct, but the length of the parameter field is however unchanged. If contents of the

Tracing a Qshell Variable

June 19, 2002 Timothy Prickett Morgan

Hey, Ted:

A variable is getting changed in a Qshell script, but I can’t determine where it’s happening. How can I track changes to a variable?

— Len

Add the following lines to the top of the script:

trap 'echo "DBG: $var = "$var""' DEBUG
set -x 

The trap command with the DEBUG condition executes the command between single quotes (‘) after each simple command of the script runs. In this case, Qshell echoes the value of a variable named var to the display. Replace var with the name of your variable.

The set command with -x option causes Qshell

LAYOUT: An Improved DSPFFD

June 19, 2002 Timothy Prickett Morgan

Note: The code accompanying this article is available for download here.

The article was revised on 12/22/14.

Dear Readers:

Tim Swearingen recently sent me a copy of his LAYOUT utility. It shows records layouts, as does the Display File Field Description (DSPFFD) command, but in a nicer format, and it also includes access path information. I liked it and thought some of you might find it helpful too.

The utility consists of four objects:

a command object called LAYOUT

a printer file called LAYOUTP

a CL program called LAYOUTC

an RPG III (RPG/400) program called LAYOUTR

Place the source