GDDM V3R2 Base Application Programming Guide
GDDM V3R2 Base Application Programming Guide
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The device GDDM V3R2 Base Application Programming Guide SC33-0867-01 |
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The device is the highest level object in the hierarchy. Your program can select a device to be used either as the current primary device, or as the current alternate device. Except for the few calls that refer to the current alternate device, all commands refer to the current primary device unless the program selects a different device as the current primary device. Likewise, the calls that are specific to the alternate device apply to the current primary alternate device unless a different alternate device is made current. The call that opens a device is DSOPEN. The call that makes a device the current primary or secondary device is DSUSE. If you want your program's output to appear only on the screen of the invoking device, then you don't need to issue either of these calls. This is because GDDM issues internal DSOPEN and DSUSE calls to make the invoking terminal the default current primary device. However, if your program is to communicate with devices other than the invoking terminal, or if you want a greater degree of control over any device, including the invoking terminal, you can issue your own DSOPEN with different parameters or use nicknames to modify the internal DSOPEN. For more information on how to use and control different devices, see "Device support in application programs" in topic 18.0. Subtopics: |
 Copyright IBM Corporation 1990, 2012 |
