This example obtains the total number of partitionable disks in the system. A partitionable disk is a physical disk drive that can be formatted into partitions.

 #define INCL_DOSDEVICES   /* Device values    */
 #define INCL_DOSERRORS    /* DOS error values */
 #include <os2.h>
 #include <stdio.h>

int main (VOID) {

 USHORT  usNumDrives  = 0;                  /* Data return buffer        */
 ULONG   ulDataLen    = sizeof(USHORT);     /* Data return buffer length */
 APIRET  rc           = NO_ERROR;           /* Return code               */

 /* Request a count of the number of partitionable disks in the system */

    rc = DosPhysicalDisk(INFO_COUNT_PARTITIONABLE_DISKS,
                         &usNumDrives,
                         ulDataLen,
                         NULL,         /* No parameter for this function */
                         0L);

    if (rc != NO_ERROR) {
       printf("DosPhysicalDisk error: return code = %u\n", rc);
       return 1;
    } else {
       printf("DosPhysicalDisk:  %u partitionable disk(s)\n",usNumDrives);
    }

   return NO_ERROR;
}