Dealing with FB and VB file in a single module

Ravi Kuchi · New User Joined: 29 May 2012 Posts: 14 Location: INDIA

Hi Friends,

Is there a possibility to write an assembler module that could open a file (it could be either FB or VB) and check if it is empty or not ?
or else
do we need to have seperate modules for each of these kind?

Thanks!

dbzTHEdinosauer · Posted: Thu Jul 19, 2012 4:38 pm

posting a question on an internet forum is RESEARCHING?

in addition to being either FB or VB, is the DSN (Dataset Name) known at run-time,
or is this dynamic?

also, do you differentiate between allocated
and allocated/opened/closed
when you mean empty?

IF the DSN is known at run-time, there are plenty of threads in the
DFSORT forum (as well as the JCL forum - syncsort as well as IBM utilities)
that deal with this question
that you could research.

So is this a question about Assembler
or the function of determining if a file is empty?

Ravi Kuchi · New User Joined: 29 May 2012 Posts: 14 Location: INDIA

Yes, The DSN name is known at run time.

Let me explain the assembler module we are trying to build.

1) The module should open the file.
2) If the file open is succesful, then it would try to read the first record.
3) If the file open is not successful then it should return with return-code 8
4) If a record is present then it should close the file and exit with return code of 4
5) If the file is empty then it should exit with return code of Zero.

Hope, I am clear.

Thanks

dick scherrer · Posted: Thu Jul 19, 2012 9:25 pm

Hello,

It is still not clear to me if the goal is the process to determine if the file is empty or the goal is just to write some assembler

What does "open not successful" mean? If the file does not exist, it cannot be opened and if named in the JCL will cause a jcl error before the code is even running.

As DBZ mentioned, look in the sort and jcl parts of the forum as there are several topics dealing with detecting an empty file.

Bill O'Boyle · Posted: Thu Jul 19, 2012 10:29 pm

If you issue an IDCAMS PRINT COUNT(0) and the RC=04, then the file is empty. COUNT(0) prevents records from being printed as their contents might not be for non-authorized eyes. Management likes precautions like this....

PeterHolland · Posted: Fri Jul 20, 2012 1:48 pm

Anuj Dhawan · Posted: Fri Jul 20, 2012 2:13 pm

It's Friday Peter, go slow...

PeterHolland · Posted: Fri Jul 20, 2012 2:23 pm

Anuj, just saying have a nice week-end.

PeterHolland · Posted: Fri Jul 20, 2012 2:38 pm

Well the strange thing is :

with a PRINT of
COUNT(0) will give a max cond code of 0
COUNT(1) will give a max cond code of 4

with a repro of the empty file to another dummy dataset :

without COUNT will give a max cond code of 0
with COUNT(1) will give a max cond code of 4

dick scherrer · Posted: Fri Jul 20, 2012 6:48 pm

Hello,

Well, it "successfully" processed zero records . . . hence the cc zero?
And unsuccessfully processes one record - so the cc 4?

The successful count of zero records varified the existence of the file (which would have caused a jcl error if it did not exist)?

Yup, kinda strange. . .

Bill O'Boyle · Posted: Fri Jul 20, 2012 9:00 pm

Peter,

COUNT(1) is the correct choice, returning an RC=04 for an empty file.

I've used this for many years. But, as CRS kicks in

, I may have been thinking of a VSE environment, where COUNT("whatever") returns an RC=04 for an empty file.

PeterHolland · Posted: Sat Jul 21, 2012 12:23 am

Hallo Bill,

with all respect, i was just doing some tests with that idcams stuff. And did you mean with CRS this ? :

crs.org/

Bill O'Boyle · Posted: Sat Jul 21, 2012 1:20 am

Hi Peter,

Actually, CRS is correct (Can't Remember Sh*t).