Re: File operations in subprocedure

[Hans Boldt <boldt@xxxxxxxxxx>]

CarollaT@xxxxxxxxxxxxxx wrote:
> Greetings!  
>
> I have started using some exception/error handling techniques (due in part
> to the scolding by Mr. Tuohy in his class ;-) ), and I have run into a
> slight snag.  I have specified on an input file the USROPN keyword, and
> specified an INFSR(*PSSR) keyword also.  My *PSSR is straight forward (this
> process runs at night, non-interactively):
>
>        BegSR *PSSR;
>        Dump(A);
>        EndSR '*CANCL';
>
> I am also using a variable (21 Alpha) for the input file.  This file
> variable will be changed several times, and the file will be closed and
> re-opened each time.  
>
> It's beautiful, so far.  So the catch is that I have also started using
> subprocedures, instead of subroutines.  I am attempting to resolve the
> ExtFile variables, and to do the closing/opening of the files entirely in a
> subprocedure.  I get two compiler errors in attempting this, as follows:
>
>
> RNF5416 The subprocedure calculation specification refers to a file that has
> the INFSR keyword specified.
>
> RNF7062 There is no OPEN for a file that specifies user-controlled open; the
> File specification is ignored.                  
>
>
> The first thing I ran into was that the EXTFILE variable must be declared in
> the main procedure's D specs (makes sense), but I don't understand what the
> above 5416 error is telling me.  Can I not do an OPEN on a file within a
> subprocedure?  And do I need to trick the 7062 error by putting a dummy
> 'OPEN' op in the main procedure.  
>
> My goal is to write non-tricky, non-complex stuff where it's unnecessary.
> What gives?

You can certainly use a file within a subprocedure. That includes 
opening and closing the file, and the reading, writing, updating, and 
deleting of records. But, you cannot use the file within the 
subprocedure if keyword INFSR is defined for the file. The reason is 
that you cannot invoke a subroutine if it is defined in a different 
procedure.

Instead, for those cases that you would handle using an INFSR, code the 
I/O statement in a MONITOR group, and then explicitly handle the 
exception in the ON-ERROR clause. Or code the (E) opcode extender and 
check %ERROR immediately after the I/O operation.

Cheers! Hans