GDDM V3R2 Base Application Programming Reference
GDDM V3R2 Base Application Programming Reference
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ASREAD GDDM V3R2 Base Application Programming Reference SC33-0868-02 |
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Function To perform device output and input. ASREAD (attype, attval, count) Parameters attype (returned by GDDM) (fullword integer)
The value, if any, associated with attype, as follows:
The number of modified fields after execution of the function. If the GDDM page is a mapped page, count returns the number of modified mapped fields in that page, even if there are modified procedural alphanumeric fields in that page. If the GDDM page is not a mapped page, count returns the number of modified procedural alphanumeric fields in that page. If the GDDM page contains high-performance alphanumerics, count is always 0. If attype=2, count contains the number of modified light-pen fields. If multiple partitions (real or emulated) are in use, the operator can move the cursor from one partition into another during the ASREAD call. If this happens, ASREAD returns the number of modified fields in the new current partition; that is, the partition that now contains the cursor. If real partitions are in use, only data from the active partition is input. The terminal user's changes in other partitions are not available. Description Performs all outstanding output, and for an interactive device, requests input from the device. The ASREAD call is completed when an attention interrupt from the device is received and the attention information is returned to the caller. Restrictions exist on the use of some keys, depending on the operating environment. For further information, see the GDDM Base Application Programming Guide. In a windowing environment, it is possible for an attention interrupt to be pending, in which case the call is completed immediately. A pending attention interrupt is created as follows; the device for which the ASREAD call is to be performed must be associated with an operator window of a windowed device, and the operator window must have a zero coordination exit; for more information on coordination exits, refer to "Special-purpose programming in GDDM" in topic 22.0. When the WSIO call is issued for the windowed device, and the end user interacts with the operator window, a pending attention interrupt is created. If an attention interrupt is already pending, it is replaced by the new pending attention interrupt. The pending attention interrupt is removed by the ASREAD call, or by any other input/output function. If the primary device is a queued printer (family-2), a system printer (family-3), or a page printer (family-4), the action of ASREAD is as described under FSCOPY. In this case, the function is not allowed if graphics retrieval is in progress; see GSGET. By default, only procedural, mapped, and high-performance alphanumeric input is available with an ASREAD call. However, an FSENAB call can be used to enable graphics or image input to be entered in response to the ASREAD call. For a plotter, pressing the Clear key on the attached workstation while ASREAD is executing cancels the output. When running in CICS transaction-independent pseudoconversational mode, the ASREAD call only receives input from the device. It never sends output to the device. For CICS transaction-dependent pseudoconversational applications, when the pseudoconversational mode is in use, the first ASREAD call in a sequence only performs its input function; it does not perform output. Subsequent calls to ASREAD work in the usual way. However, there are two exceptions to this rule:
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 Copyright IBM Corporation 1990, 2012 |
