System i: Monitoring for zero records in the from-file

Monitoring for zero records in the from-file

There are some special considerations for copy when the from-file is a physical or logical file and one or more members to be copied are empty. A member is considered empty in the following cases:

You specified COMPRESS(*NO) on the CPYF command, and the from-file member contains no records.

You specified COMPRESS(*YES) for a COPY command, and the from-file members contain no undeleted records.

Members copied involving record selection (CPYFRMQRYF command or the INCCHAR and INCREL parameters of the CPYF command) that produce no records are not considered empty.
When the to-file is a printer file (including *PRINT), or when the to-file is a physical file and you specified MBROPT(*ADD) or MBROPT(*UPDADD), empty from-file members are copied because no existing data will be destroyed. Each member that is copied is identified by a normal copy completion message. If the to-file is spooled, an empty spooled file is produced for each empty from-file member. If the PRINT parameter on the CPYF command specifies *COPIED, *EXCLD, or *ERROR, the empty members are shown in the lists, and no records are printed. Except for the CPYFRMQRYF command, an empty from-file member is never copied to a diskette or tape file, or to a physical file when MBROPT(*REPLACE) is specified. Empty from-file members are skipped for these types of to-files, and a CPF2869 message is sent (as either an informational or diagnostic message) to identify each empty member. The empty members are skipped to avoid destroying existing data. When an empty from-file member is skipped, the following considerations apply:

A tape or diskette file is not produced on the output volume. If the diskette file is spooled, no spool output file is created.

An existing to-file physical file member is not cleared.

If the to-file does not exist and you specified CRTFILE(*YES) on a copy command, a physical file is created.

If the to-file is a physical file and the to-file member does not exist, a member is added to the file.

If the PRINT parameter on the CPYF command specifies *COPIED, *EXCLD, or *ERROR, the empty members are not shown in the lists.

When the copy command specifies a generic name or *ALL for the FROMMBR parameter, each empty from-file member skipped is identified by message CPF2869, sent as an informational message. If all the from-file members are skipped, a CPF2870 diagnostic message is sent after all the CPF2869 informational messages, followed by a CPF2817 escape message.
When the copy command specifies a single member name or FROMMBR(*FIRST), or when there is an override for the from-file that forces a single member to be processed, an empty member that is skipped is identified by the diagnostic message CPF2869. The CPF2869 diagnostic message is followed by a CPF2817 escape message. In the following example, the from-file and to-file are both database files, and EMPTY1 and EMPTY2 are empty members in the from-file.
By using the code examples, you agree to the terms of the Code license and disclaimer information.
PGM           /* No need to monitor for zero records              when MBROPT(*ADD) specified    */
CPYF    FROMFILE(D504/GEORGE) TOFILE(D504/KEN) +
  FROMMBR(EMPTY1) TOMBR(MBR1) MBROPT(*ADD)
CPYF    FROMFILE(D504/GEORGE) TOFILE(D504/KEN) +
  FROMMBR(EMPTY2) TOMBR(MBR2) MBROPT(*REPLACE)
MONMSG  MSGID(CPF2817) CMPDTA(CPF2869) +
  EXEC(CLRPFM  FILE(D504/KEN) MBR(MBR2))
          /* Monitor for zero records and              send a message when all members              to copy are empty */
CPYF    FROMFILE(D504/GEORGE) +
  TOFILE(D504/NEWFILE) FROMMBR(EMPTY*) +
  TOMBR(NEWMBR) MBROPT(*REPLACE)
MONMSG  MSGID(CPF2817) CMPDTA(CPF2870) +
  EXEC(SNDPGMMSG TOPGMQ(*EXT) +
  MSG('All members to copy are empty'))
ENDPGM
For the first CPYF command, MBROPT(*ADD) is specified, so an escape message is not sent to the program because of the empty from-file member. Note that if MBR1 does not exist before the copy, it is added to the to-file (if either the from-file member is empty or contains data).
For the second CPYF command, copy does not clear the to-file member when the from-file member is empty, so the MONMSG command after the second CPYF command starts the CLRPFM command to clear the to-file member when the from-file member is empty.
For the third CPYF command, the CPF2817 escape message has compare data of CPF2870 if all members to be copied are empty because the generic from-file member name, EMPTY*, requests that multiple members be copied.

Parent topic:
Copying files: Basic functions