DevQueryCaps - Example Code

In this example the driver is queried to see if it supports input, output, or both. Note that a valid device context handle must be passed. This example assumes a DevOpenDC call has been made to obtain the device context handle.

#define INCL_DEV
#include <OS2.H>

HDC hdc;
LONG lStart;
LONG lCount;
BOOL flreturn;
LONG alArray[CAPS_TECHNOLOGY];
lCount = CAPS_TECHNOLOGY;
lStart = CAPS_FAMILY;

flreturn = DevQueryCaps(hdc,        /* device context handle */
                       lStart,      /* number of first item  */
                       lCount,      /* count of items        */
                       alArray);    /* array of longs which  */
                                    /* will contain the return */
                                    /* information.            */

switch(alArray[CAPS_IO_CAPS])       /* we test the CAPS_IO_CAPS */
                                    /* element of the array to  */
                                    /* find out which options   */
{                                   /* are supported.           */
 case CAPS_IO_SUPPORTS_OP:             /* device supports output.*/

 break;
 case CAPS_IO_SUPPORTS_IP:            /* device supports input. */

 break;
 case CAPS_IO_SUPPORTS_IO:            /* device supports both  */
                                    /* input and output.       */
 break;
 default:
 break;
}