Thread: LPSTR Size

Morning.

LPSTR is just a *char isn't it...

If this is the case, does a string variable (i.e. lpszString) created with LPSTR have the same restrictions on size as a single char?

i.e., if I stored an integer value in lpszString, would it only go up to 255?

It's my first venture into C++ with a complex app (company policy - deep end!) that needs some fixes.

Cheers

DS

An LPSTR is just a char* thus it's only a pointer, so it's size is only sizeof(char*) bytes.

>> i.e., if I stored an integer value in lpszString, would it only go up to 255?

I'm unsure of why you'd want to store an integer in a LPSTR.

The reason for using LPSTR with integer values is that the code I am working on uses TextOut to write out the values.

There is also a function to insert commas into the numeric values for thousands, millions etc.

Magos -

xGlobalAlloc is used to allocate memory for the variable.

I think I understand what you mean. This would be the reason for using LPSTR rather than just using char.

This is the code I am working from:

Code:

/****************************************************************/
/* FormatAndPrint - print vpData at nXpos, nYpos in hDCDisplay */
/****************************************************************/
void  FormatAndPrint(HDC   hDCDisplay,
                     void  _far *vpData, // Numeric value
                     int   nXpos,
                     int   nYpos,
                     BOOL  bNumbers)
{
   LPSTR    lpszNewString = NULL;
   HANDLE   hNewString    = 0;

   if (hNewString = xGlobalAlloc(GMEM_MOVEABLE | GMEM_DISCARDABLE | GMEM_ZEROINIT, 255))
   {
      if (lpszNewString = GlobalLock(hNewString))
      {
         if (bNumbers)
         {
            InsertCommas(&lpszNewString, vpData);
            TextOut(hDCDisplay, nXpos, nYpos, lpszNewString, lstrlen(lpszNewString));
         }
         else
            TextOut(hDCDisplay, nXpos, nYpos, (LPSTR)vpData, lstrlen(vpData));

         GlobalUnlock(hNewString);
      }
      xGlobalFree(hNewString);
   }
}

/********************************************************************/
/* InsertCommas - formats a numeric string (with commas) and passes */
/*                it back via the FormatString variable             */
/*                                                                  */
/*        input - lppszFormatString - the string which will contain */
/*                                    the modified number           */
/*                plNumber - the number we wish to format           */
/*                                                                  */
/********************************************************************/
void  InsertCommas(LPSTR _far *lppszFormatString, LONG   _far *plNumber)
{
   LONG  lCopyNumber =  labs(*plNumber);

   LPSTR   lpszWorkString = NULL;

   HANDLE   hWorkString    = 0;

   if (hWorkString = xGlobalAlloc(GMEM_MOVEABLE | GMEM_DISCARDABLE, 255))
   {
      if (lpszWorkString = GlobalLock(hWorkString))
      {
         int   nCommas    = 0,
               nLastComma = 0,
               nStrLen    = 0,
               nCommaCnt  = 0,
               nCounter   = 0;

         /* copy it, flip it and get the stats */
         wsprintf(lpszWorkString, "%ld", lCopyNumber);
         _fstrrev(lpszWorkString);
         nStrLen = lstrlen(lpszWorkString);

         nCommaCnt = nStrLen / 3;
         nLastComma = nCommaCnt * 3;

         for (nCounter = 0; nCounter < nStrLen; nCounter++)
         {
            /* comma position ? */
            if ((nCounter / 3) * 3 == nCounter && nCounter != 0)
            {
               *(*lppszFormatString + nCounter + nCommas) = ',';
               nCommas++;
            }

            *(*lppszFormatString + nCounter + nCommas) = *(lpszWorkString + nCounter);
         }

         /*   adjust for negatives   */
         if (*plNumber < 0)
            lstrcat(*lppszFormatString, "-\0");

         _fstrrev(*lppszFormatString);

         GlobalUnlock(hWorkString);
      }
      xGlobalFree(hWorkString);
   }
   else
      lstrcpy(*lppszFormatString, "!Error!");
}

(FYI: These are the actual variable names used in this code - handy eh!)

My concern with this is that we are losing some accuracy with basically frigging around with the data, and I was unsure as to whether the entire integer value would be passed into TextOut.

Cheers (or sorry?)

DS