Mainframe, MVS and zOS Discussion

Hi,

Enterprise Cobol support dynamic allocation for files by using of an environment variable named with DDname and parameters for dataset for allocation. But if we try to allocate a SYSOUT, this raise an error IGZ0251W at run time. We can use BPXWDYN but can there be full COBOL approach for it?

Your post is unclear; are you attempting to allocate to DD name SYSOUT, or are you trying to allocate a SYSOUT=<something>?  For the former, this quote from Enterprise COBOL V5.2 Programming Guide may be relevant:

[font=serif]Two files should not use the same ddname or environment variable name in their[/font]
[font=monospace]SELECT[/font][font=serif]clauses; otherwise, results could be unpredictable. For example, if[/font][font=monospace]DISPLAY[/font]
[font=serif]output is directed to[/font][font=monospace]SYSOUT[/font][font=serif], do not use[/font][font=monospace]SYSOUT[/font][font=serif]as the ddname or environment[/font]
[font=serif]variable name in the[/font][font=monospace]SELECT[/font][font=serif]clause for a file.[/font]

There was a recent Request For Enhancement (RFE) submitted to IBM to allow this. It was declined, although the decline messages refers to //SYSOUT DD ... not to //dddd DD SYSOUT=*.

Robert Sample wrote:Your post is unclear; are you attempting to allocate to DD name SYSOUT, or are you trying to allocate a SYSOUT=<something>?  For the former, this quote from Enterprise COBOL V5.2 Programming Guide may be relevant:

[font=serif]Two files should not use the same ddname or environment variable name in their[/font]
[font=monospace]SELECT[/font][font=serif]clauses; otherwise, results could be unpredictable. For example, if[/font][font=monospace]DISPLAY[/font]
[font=serif]output is directed to[/font][font=monospace]SYSOUT[/font][font=serif], do not use[/font][font=monospace]SYSOUT[/font][font=serif]as the ddname or environment[/font]
[font=serif]variable name in the[/font][font=monospace]SELECT[/font][font=serif]clause for a file.[/font]

I was asking for allocating the DD name SYSOUT.
From the quote it means that we can not do that, is that right?

The quote is telling you that if you allocate SYSOUT DD name via a SELECT statement, you had better not have any DISPLAY statements in your program (not now nor ever in the future) or you will get unpredictable results.

But is not allocating SYSOUT using SELECT is different than allocating a DD name dynamically?

No!  Dynamic allocation is still allocating a dataset to a DD name.  You will get unpredictable results if you allocate to DD name SYSOUT no matter HOW you do the allocation.

Thanks everyone.