ch05l06.txt

《Web编程专家指南》

Listing 5.6 The server code that supports DGI.

int  ClientAgent :: LoadExt (const string &sModName, const string &sQuery, const string &sPathInfo, const string &sFormData)
{
   APIRET   rc;
   char     szObjNameBuf [128];
   HMODULE  hModHandle;
   rc = DosLoadModule(szObjNameBuf, sizeof szObjNameBuf, sModName.c_str(), &hModHandle);
   if (rc != 0) {   // load the module in memory 
      TRACE(cerr<<"Unable to load "<<sModName<<" module [" <<rc<< "]" << endl;);
      return rc;
   }

/* module loaded, resolve functions address */
   PDGI_FN_START    fnStart;
   PDGI_FN_DOACTION fnDoAction;
   PDGI_FN_END      fnEnd;
   PFN              pProcAddr;

   rc = DosQueryProcAddr(hModHandle, 1, 0, &pProcAddr);

   if (rc != 0) {
      TRACE (cerr<< "Error [" << rc << "] addressing Start function" << endl;);
      fnStart = 0;
   } else fnStart = (PDGI_FN_START) pProcAddr;
   rc = DosQueryProcAddr(hModHandle, 2, 0, &pProcAddr);
   if (rc != 0) {
      TRACE (cerr<<"Error [" << rc << "] addressing Action function" << endl;);
      fnDoAction = 0;
   } else fnDoAction = (PDGI_FN_DOACTION) pProcAddr;

   rc = DosQueryProcAddr(hModHandle, 3, 0, &pProcAddr);

   if (rc != 0) {
      TRACE (cerr << "Error [" << rc << "] addressing End function" << endl;);
      fnEnd = 0;
   } else fnEnd = (PDGI_FN_END) pProcAddr;

   TRACE(printf ("Start: %p\n", fnStart););
   TRACE(printf ("Do: %p\n", fnDoAction););
   TRACE(printf ("End: %p\n", fnEnd););

   /* Invoke start function */
   long  retCode;

   if ((retCode = fnStart(putHtml, getData, (void *)this)) != 0) {
      TRACE (cerr << "Start OK" << endl;);       // OK
   } else {TRACE (cerr << "Start in error" << endl;);}
char  szUrl [2560];

   szUrl[0] = '\0';

   if ((retCode = fnDoAction (sQuery.c_str(),     sPathInfo.c_str(),
                              sFormData.c_str(),  szUrl ) ) != 0){   // OK
      TRACE (cerr << "DoAction OK" << endl;);
   } else {
      TRACE (cerr << "DoAction in error" << endl;);
   }

   if ((retCode = fnEnd()) != 0) {  // OK
      TRACE (cerr << "End OK" << endl;);
   } else {
      TRACE (cerr << "End in error" << endl;);
   }

   DosFreeModule (hModHandle);

   // check if external module has rquested redirection
   if (strlen(szUrl)) {
      if (strstr(szUrl,"http:")) {
         char  msg [512];
         fprintf (stderr, "Returning 301 ERROR\n");
         sprintf (msg, "HTTP/1.0 301 \"HTTPD/2 Server\"\r\n"
                       "Server: A.Montefusco 3.0 -- on OS/2 2.x+\r\n"
                       "Location: %s\r\n\r\n",
                  szUrl);
         pCn->Send (msg, strlen(msg));
      } else
         print (string(szUrl), TYPE_HTML);
   }
   return 0;
}