Query Host Update – Function 24

This function determines if the presentation space, Operator Information Area (OIA), or both, of the specified Host session have been updated since one of the following occurs:

•

Start Host Notification (function 23) was called.

•

The previous call of this function.

Prerequisite functions

Start Host Notification (function 23)

Function call

WinHLLAPI(QUERYHOSTUPDATE,lpbyString,lpwLength,lpwReturnnCode)

Call parameters

Parameter	Description
Data String	Short name session ID of the desired Host session, or space or null for the current Host session.
Data Length	NA (length of 1 is implied).
PS Position	NA

Return code

Code	Description
WHLLOK	No updates.
WHLLNOTCONNECTED	The specified Host session is invalid.
WHLLSYSERROR	The function failed due to a system error.
WHLLOIAUPDATE	One or more updates to the OIA of the specified Host session.
WHLLPSUPDATE	One or more updates to the presentation space of the specified Host session.
WHLLBOTHUPDATE	One or more updates to both the OIA and the presentation space of the specified Host session