RE: Procedures are FUN!

["Mackie, Roger L. (Precision Press)" <RLMackie@xxxxxxxxxxxxx>]

Joe,

In our shop we had the same problem when we started moving from subprograms
to service programs. Since we cannot redo all our programs at once, the
service programs must be able detect whether the file as already been opened
in the activation group by a program lower on the call stack. If it has, the
service program cannot close it or it will be closed to all the programs in
the activation group. We stumbled across this technique:
1. set all files in the service program module(s) to USROPN.
2. If %OPEN reports the file as open, use the file as if the module had
opened it.
3. If %OPEN reports the file as closed:
   a. Open the file;
   b. Set a locally defined named indicator *ON (perhaps CloseXxxxxx);
   c. When the subprocedure is done with the file, check the indicator;
   d. Only close the file if the indicator is on.

It would be better to control the opening of the file in other programs in
the activation group, but we do not have the resources to do that right now.
This has worked for us in our mixed-style environment.

HTH,
Roger Mackie

-----Original Message-----
From: Joe Pluta [mailto:joepluta@PlutaBrothers.com]
Sent: Monday, October 14, 2002 14:10
To: rpg400-l@midrange.com
Subject: RE: Procedures are FUN!

<SNIP>
I started out by getting "File already open or in error"
(CPF4132) in the *INIT of the subprogram.  Next, I tried making the files
USROPN, and opening them once in the subprocedure based on a static
variable.  Still errors in the subprogram call.  I finally went so far as to
check to see if the file was open using the %open BIF, and then if not
attempting to open the file, but when I come through the mainline, I get
CPF4132.

<SNIP>