MDOFF (10-digit signed integer)

Offset of data in physical message from start of logical message.

This is the offset in bytes of the data in the physical message from the start of the logical message of which the data forms part. This data is called a segment. The offset is in the range 0 through 999 999 999. A physical message which is not a segment of a logical message has an offset of zero.

This field need not be set by the application on the MQPUT or MQGET call if:

These are the recommended ways of using these calls for messages that are not report messages. However, if the application does not comply with these conditions, or the call is MQPUT1, the application must ensure that MDOFF is set to an appropriate value.

On input to the MQPUT and MQPUT1 calls, the queue manager uses the value detailed in Table 31. On output from the MQPUT and MQPUT1 calls, the queue manager sets this field to the value that was sent with the message.

For a report message reporting on a segment of a logical message, the MDOLN field (provided it is not OLUNDF) is used to update the offset in the segment information retained by the queue manager.

On input to the MQGET call, the queue manager uses the value detailed in Table 16. On output from the MQGET call, the queue manager sets this field to the value for the message retrieved.

The initial value of this field is zero. This field is ignored if MDVER is less than MDVER2.