The un*x to OS/2-EMX Porting FAQ (pibtst.c)

This is the pibtst.c sampled from The un*x to OS/2-EMX Porting FAQ article:

/**********************************************************************
 * pibtst.c
 *
 * Shows how to modify the PIB so that an OS/2 VIO program can
 * dynamically "morph" into an OS/2 PM program.  An interesting
 * side-effect of the morphing process is that stdout/stdin are still
 * tied to the VIO window.  In other words, printf() and gets() will
 * will write to and read from the OS/2 Window from where the program
 * was started.  Of course, reading from stdin inside a window
 * procedure is not a good idea.
 *
 * The modification of the PIB can be moved after the call to
 * WinInitialize(), but must occur before the call to
 * WinCreateMsgQueue().  You can also reset the pib->pib_ultype field to 2
 * (the value for an OS/2 VIO session) after the call to
 * WinCreateMsgQueue() without losing the ability to create windows.
 * You will probably not be able to create a message queue in another
 * thread if you reset this field, though.
 *
 * Note that the PIB being in a read/write area is in fact documented
 * behavior.  See DosGetInfoBlocks in the Control Program Guide and
 * Reference. 
 *
 * To compile the program:
 *    gcc -o pibtst.exe -DMORPH pibtst.c     (EMX)
 *    icc /Fepibtst.exe /DMORPH pibtst.c     (VACPP or C/Set++)
 *
 * Remove the -DMORPH or /DMORPH in the above lines to see how the
 * program behaves without setting pib->pib_ultype.
 *
 * Darren Abbott
 * abbott@hiwaay.net
 *
 * The included binary was created by: 
 *    gcc -DMORPH -O3 -s -o pibtst.exe pibtst.c -Zmt -Zsys -Zomf -Zsmall-conv
 *
 *********************************************************************/

#include <stdio.h>
#include <stdlib.h>

#define INCL_DOSPROCESS
#define INCL_WINWINDOWMGR
#define INCL_WIMMESSAGEMGR
#define INCL_WINDIALOGS
#include <os2.h>

static MRESULT EXPENTRY ClientWndProc(HWND hwnd, ULONG msg,
				      MPARAM mp1, MPARAM mp2);
int main(void) {
   HAB hab;
   HMQ hmq;
   PPIB pib;
   PTIB tib;
   BOOL rc;
   HWND hwndFrame;
   HWND hwndClient;
   ULONG fcf;
   QMSG  qmsg;
   char input[80];
   char className[] = "TestClass.Win";

   DosGetInfoBlocks(&tib, &pib);
   printf("pib->pib_ultype = %d\n", pib->pib_ultype);

#ifdef MORPH
   /* Try morphing into a PM application. */
   pib->pib_ultype = 3;
   printf("pib->pib_ultype = %d\n", pib->pib_ultype);
#endif

   hab = WinInitialize(0);
   printf("hab = %d\n", hab);

   hmq = WinCreateMsgQueue(hab, 0);
   printf("hmq = %d\n", hmq);
   printf("Type enter to continue\n");
   gets(input);

   /* Create a simple window. */
   rc = WinRegisterClass(hab, className, ClientWndProc, CS_SIZEREDRAW, 0L);
   if (!rc) {
      printf("WinRegisterClass failed\n");
   }

   fcf = FCF_TASKLIST | FCF_SYSMENU | FCF_SIZEBORDER |
      FCF_SHELLPOSITION | FCF_TITLEBAR | FCF_MINBUTTON;
   hwndFrame = WinCreateStdWindow(HWND_DESKTOP, WS_VISIBLE,
                                  &fcf, className, "Test",
                                  0L, 0, 1, &hwndClient);

   if (!hwndFrame) {
      printf("WinCreateStdWindow error\n");
   }

   printf("%s: %d\n", __FILE__, __LINE__);

   while (WinGetMsg(hab, &qmsg, 0L, 0, 0))
      WinDispatchMsg(hab, &qmsg);

   WinDestroyWindow(hwndFrame);
   WinDestroyMsgQueue(hmq);
   WinTerminate(hab);

   printf("%s: %d\n", __FILE__, __LINE__);
   return 0;
}

static MRESULT EXPENTRY ClientWndProc(HWND hwnd, ULONG msg,
				      MPARAM mp1, MPARAM mp2) {
   HPS hps;
   RECTL rcl;
   static char codeName[80] = { "Test Window" };

   switch (msg) {
      case WM_CREATE:
         printf("WM_CREATE\n");
         break;

      case WM_CLOSE:
         printf("WM_CLOSE\n");
         WinPostMsg(hwnd, WM_QUIT, 0, 0);
         break;
      case WM_PAINT:
         printf("WM_PAINT\n");
         hps = WinBeginPaint(hwnd, NULLHANDLE, NULL);
         WinQueryWindowRect(hwnd, &rcl);
         GpiSetColor(hps, CLR_DARKCYAN);
         WinDrawText(hps, -1, codeName, &rcl, 0, 0,
                     DT_TEXTATTRS | DT_CENTER | DT_VCENTER | DT_ERASERECT);
         WinEndPaint(hps);
         break;
      default:
         return WinDefWindowProc(hwnd, msg, mp1, mp2);
   }
   return 0;
}