I would like to thank everyone for their responses. I have always hated
the PURGE / BUILD in job streams, but generally just wrote my COBOL to
handle file status codes and accomplish what I wanted, and so avoided
this problem. Now that I have other fish to fry, I will be using this
approach. I do have one question. I tested this with a KSAM file, and
this preserves the create date, and changes the access date, but did
nothing to the modified date! Now, I would consider the loss of all
records to be more of a modification than browsing records, and would
expect that date to change as well. Why does this happen this way?

>----------
>From:  John Clogg[SMTP:[log in to unmask]]
>Sent:  Thursday, January 22, 1998 11:33 AM
>To:    [log in to unmask]
>Subject:       Re: [HP3000-L] Emptying an NM KSAM file
>
>This works, but not in the way described.  The file does not get purged
>and rebuilt.  The way the CI purges a file is to open it and then close it
>with a disposition of purge.  The file command's SAVE option overrides
>that disposition.  The same file still exists, but it is empty because the
>CI's
>FOPEN also opened it with ACC=OUT, which sets the EOF to the
>beginning of the file.  If you add ACC=IN to the file command, the file will
>be unchanged.