Gets the band of the first message on the stream-head read queue.
The I_GETBAND operation returns the priority band of the first message on the stream-head read queue in the integer referenced by the arg parameter.
If unsuccessful, the errno global variable is set to the following value:
|ENODATA||No message is on the stream-head read queue.|
This operation is part of STREAMS Kernel Extensions.
The streamio operations.
Understanding STREAMS Messages in AIX Version 4.3 Communications Programming Concepts.