_MemoSize( ) API Library Routine Example

The following example retrieves the contents of a memo field for the current record. _MemoSize( ) is used to determine how much memory should be allocated for a buffer, and how many bytes should be read from the memo file.

Visual FoxPro Code

SET LIBRARY TO MEMOSIZE
CREATE TABLE WMemo (MemoField M)
APPEND BLANK
REPLACE MemoField WITH "Hello, World."
? GETMEMO(@MemoField)

C Code

#include <pro_ext.h>

FAR FindMemoEx(ParamBlk FAR *parm)
{

   Locator FAR *memoFldLoc;
   FCHAN fchMemo;
   char FAR *memoContents;
   int memoLen;
   long loc;

   if ((fchMemo = _MemoChan(-1)) == -1)
   {
      _UserError("_MemoChan() failed");
   }
   memoFldLoc = &parm->p[0].loc;

   if ((loc = _FindMemo(memoFldLoc)) < 0)
   {
      _UserError("_FindMemo() failed");
   }
   if ((memoLen = _MemoSize(memoFldLoc)) < 0)
   {
      _UserError("_MemoSize() failed");
   }
   if ((memoContents = _Alloca(memoLen + 1)) == 0)
   {
      _Error(182); // "Insufficient memory"
   }
   _FSeek(fchMemo, loc, FS_FROMBOF);
   _FRead(fchMemo, memoContents, memoLen);
   memoContents[memoLen] = '\0';
   _RetChar(memoContents);
}

FoxInfo myFoxInfo[] = {
   {"GETMEMO", (FPFI) FindMemoEx, 1, "R"},
};
FoxTable _FoxTable = {
   (FoxTable FAR *) 0, sizeof(myFoxInfo)/sizeof(FoxInfo), myFoxInfo
};