DosLoadModule - Example Code

This example loads the dynamic link module "DISPLAY.DDL," queries its address and type, and finally frees it.

 #define INCL_DOSMODULEMGR     /* Module Manager values */
 #define INCL_DOSERRORS        /* Error values */
 #include <os2.h>
 #include <stdio.h>

int main(VOID) {

 PSZ      ModuleName     = "C:\\OS2\\DLL\\DISPLAY.DLL";  /* Name of module   */
 UCHAR    LoadError[256] = "";          /* Area for Load failure information */
 HMODULE  ModuleHandle   = NULLHANDLE;  /* Module handle                     */
 PFN      ModuleAddr     = 0;           /* Pointer to a system function      */
 ULONG    ModuleType     = 0;           /* Module type                       */
 APIRET   rc             = NO_ERROR;    /* Return code                       */

   rc = DosLoadModule(LoadError,               /* Failure information buffer */
                      sizeof(LoadError),       /* Size of buffer             */
                      ModuleName,              /* Module to load             */
                      &ModuleHandle);          /* Module handle returned     */
   if (rc != NO_ERROR) {
      printf("DosLoadModule error: return code = %u\n", rc);
      return 1;
   } else {
      printf("Module %s loaded.\n", ModuleName);
   } /* endif */

   rc = DosQueryProcAddr(ModuleHandle,         /* Handle to module           */
                         1L,                   /* No ProcName specified      */
                         NULL,                 /* ProcName (not specified)   */
                         &ModuleAddr);         /* Address returned           */
   if (rc != NO_ERROR) {
      printf("DosQueryProcAddr error: return code = %u\n", rc);
      return 1;
   } else printf("Address of module is 0x%x.\n", ModuleAddr);

   rc = DosQueryProcType(ModuleHandle,         /* Handle to module           */
                         1L,                   /* Indicate no ProcName given */
                         NULL,                 /* ProcName (not specified)   */
                         &ModuleType);         /* Type 0=16-bit   1=32-bit   */
   if (rc != NO_ERROR) {
      printf("DosQueryProcType error: return code = %u\n", rc);
      return 1;
   } else printf("This is a %s module.\n", ( ModuleType ? "32-bit" : "16-bit"));

   rc = DosFreeModule(ModuleHandle);
   if (rc != NO_ERROR) {
      printf("DosFreeModule error: return code = %u\n", rc);
      return 1;
   } else printf("Module %s freed.\n", ModuleName);

   return NO_ERROR;
}