Re: Running a program with a display file in batch

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

> Can this be done?  We have a program someone modified to not ever display a
> screen in the program.  They still update the fields and update the subfiles
> but they changed it to never do a exfmt so that they could run it without
> user intervention.

But, the operating system doesn't know that you're never going to display 
a screen.  You've opened a display file -- a file that's designed for 
screen i/o -- so it makes sure that there's a terminal allocated to the 
job.

> Now we need to be able to run this same program in batch.  But it says: 
> CPF4103 Device *REQUESTER not found while opening file xxxxxx.  Is there 
> a way around this?
> Can I make the program think it's somehow running on a interactive 
> display?

Sure. Even though the program's in batch, you can tell the display file to 
access a different terminal. For example, you could do:

  OVRDSPF FILE(myDspf) DEV(DSP01)

And DSP01 would handle the i/o for the display file. Of course, that 
terminal would have to be turned on, but not in use, for this to work.

Another alternative is to use TNAPI by Albert York. This is a tool that 
creates a telnet session that writes it's output to an RPG program. You 
can then control the session by sending input to the telnet session 
programatically, etc.

In that case, the batch job will be creating a separate interactive job to 
run the program.

HOWEVER, the correct fix is to eliminate the display file completely, 
since your program isn't using it anyway. It's trivial to replace subfile 
logic with a multiple-occurrence data structure.

That, in the long run, will be the best fix. It'll run faster, there'll be 
less that can go wrong, and the code will be much more intuitive for the 
next person who has to figure it out.  Really, it's the way to go.  It's 
just silly to use a display file when you have no interest in 
communicating with a display! :)