End-of-Data or end-of-volume on input

The system's EOV routine handles both end-of-data-set and end-of-volume conditions on input. These conditions occur when either a tape mark is read or an FEOV macro instruction is executed by the processing program.

After encountering a tape mark, the system checks the first 4 bytes of the first trailer label for the identifier EOV1 or EOF1. Processing is abnormally terminated if neither identifier is found.

When the FEOV macro is issued, the identifier of the first trailer label is not checked. The trailer labels on the current volume are not processed, but the volume labels and header labels on the next volume are processed.

For an end-of-data condition, the first trailer label is processed, unless deferred user input trailer label processing is specified in the DCB exit list. For an end-of-volume condition, the first trailer label on the current volume is processed, and then the volume label and header labels on the next volume are processed.

Except when it is used as a header label for a RDBACK operation, the system ignores the second trailer label (EOV2 or EOF2) of an input data set. Unless the tape is read backward and the trailer labels are used as header labels, trailer labels are not validated for Version 3 or Version 4 standards.

If UTLs are present on input, the system can make them available to your program. To make them available, AUL must be coded on the DD statement and the address of an input user trailer label routine must be specified in the DCB exit list.