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[alexok]

Hi, I have several datasets concatenated under a DD statement and have to discover which one is being read at a given moment.

So far, I've tried 2 approaches, both of them to no avail:
1) Sending SVC 99
2) Using EXTRACT VTIOT,'S',FIELDS=(TIOT)

The problem is TIOT will always assign the first dataset in a concatenation to the DDname, all others will be given BLANKS to their DDnames. And I erroneously thought it would be updated to the currente dataset being read

The same happens when I try to use SVC 99 to make a consult...

Please. Does anyone know how to address this?

Thanks,
Alexandre Okaue

[ofer71]

Take a look at the JFCB data area. Take a closer look at JFCBDSNM field.

O.
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[alexok]

Hi, I'm not sure if I understand what you are trying to say. Ok, I'm extracting the dsname from this field, but this is where my problem resides...
You see, I have several datasets concatenated under a ddname, then I want to know which dsname (from the several dsns concatenated) is being read, but much for my dismay, the only thing jfcbdsnm contains is the first dataset from the concatenation
I'm still trying to figure out how to do this once TIOT and JFCB don't seem to contain info or a pointer indicating which dataset is being processed in a dataset concatenation
Thanks,
Alex

[semigeezer]

It has been a decade since I did assembler I/O, but... Is this reading sequential files or concatenated PDSes? When reading PDS directories of a concatenation, I think you need to do an explicit action (FEOV?) so you could just keep a count of the number of times you did that. For individual members, BLDL will give you the concatenation # for the 1st occurence of the member. For reading sequential files, I don't know how this would be done. Maybe there are other control blocks that you can find that will have information (DCB, DEB, etc) that will be able to point you to a concatenation # in the TIOT. There is a published interface to extract the TIOT entries, but reading it directly works and is fairly easy. Since I did this there have been many additions including more supported multivolume formats, compression, etc, so I'm not sure there is a simple answer like finding TTRs and cross referencing or anything like that.