Read considerations

 

The system takes specific actions when it does not find an end-of-file label or when it reads a tape block that is not a valid length.

• If the system does not find an end-of-file label, processing will continue until the system uses all the specified volume identifiers. If the program specifies VOL(*NONE), then the system processes the tapes until reaching the specified number of reels (REELS parameter). The system sends a message CPA5230 to the system operator message queue when all the identifiers in the VOL list are processed. When you receive this message, you have the following options:

  • Cancel processing of the device file immediately. The system will close the device file.

  • Continue, in order to process other volumes.

• When the system reads a tape block that is not a valid length, the system sends a CPF5036 notify message. If your high-level language reports this condition to your program, it can continue to process by reading another record. When you continue this way, the system skips the block that is not valid so your program does not receive any records from this block.

 

Parent topic:

Input/output processing for tape