The heap handle assigned. A heap handle of zero means the open failed.
status-word
The status word for the heap, set to zero on the open. When
status-word (1:1) = '9', binary values in the second status byte are:
000
Heap closed by user request
001
Heap access failure - out of buffers
002
Heap deallocated while program inactive
014
Backing-file failure: too many files
037
Backing-file failure: file access denied
201
Backing-file failure: I/O failure
status-word remains associated with the heap until the heap is closed; the first byte is set to ASCII zero by a successful OPEN; status-word is written as file status data by a subsequent heap READ, WRITE or CLOSE that encounters allocation or I/O errors (but is not reset to zero by successful operations).
If a program in which a heap status word actually exists (that is, it is not in a Linkage Section) is canceled, all heaps with status words in that program are automatically canceled, and the heap identifiers (which might have been passed to other programs) should not be used any more.