C / C++ / MFC

<br />
#include<afx.h><br />
#include<stdio.h><br />
<br />
int main()<br />
{<br />
    // Initialize MFC<br />
    if (!AfxWinInit(::GetModuleHandle(NULL), NULL, ::GetCommandLine(), 0))<br />
    {<br />
        _tprintf(_T("Fatal Error: MFC initialization failed\n"));<br />
        return 1;<br />
    }<br />
    // m_ is a C++ convention to indicate a variabe is a data member<br />
    // of a class. Also by convention, the first letter after the<br />
    // underscore is lower case. For example, it would be m_logFile.<br />
    // These are local variables, thus the m_ has been removed.<br />
<br />
    CFile logFile, dataFile;<br />
<br />
    // the char *a has been moved below, closer to where it is actually<br />
    // being used.<br />
<br />
    // The share mode should probably be deny write to prevent someone<br />
    // from using while attempting other operations.<br />
    dataFile.Open("E:/data.txt", CFile::modeRead|CFile::shareDenyWrite);<br />
<br />
    // the try block is not needed since CFile::Open does not throw<br />
    // an exception. (The CFile constructor throws an exception.)<br />
    // Instead, we pass CFileException as a parameter and check the BOOL<br />
    // return.<br />
    // I also added ShareDenyWrite to prevent any other program from writing<br />
    // to the file at the same time.<br />
<br />
    CFileException err;<br />
    if (!logFile.Open("E:/data1.txt", CFile::modeReadWrite|CFile::modeCreate|CFile::modeNoTruncate|CFile::shareDenyWrite, &err))<br />
    {<br />
        // If I remember, this pops up a message box. For console apps<br />
        // it's generally better to use _tprintf() or _tputs()<br />
<br />
        err.ReportError();<br />
        return 1;<br />
    }<br />
    logFile.SeekToEnd();<br />
<br />
    // since we aren't using smart pointers for pBuffer, <br />
    // this reduces having to add a delete before an<br />
    // explicit error return.<br />
    int rval = 0;<br />
  <br />
    // Allocate the buffer here. Note I used the convention of a p for<br />
    // pointer. This is the extent of my general notation rules.<br />
    int bufferLen = dataFile.GetLength();<br />
    char* pBuffer = new char[bufferLen];<br />
    if (dataFile.Read(pBuffer, bufferLen) == dataFile.GetLength())<br />
    {<br />
        if (logFile.Write(pBuffer, bufferLen) != bufferLen)<br />
        {<br />
            _tprintf("Error writing file\n");<br />
            rval = 1;<br />
        }<br />
    }<br />
    delete [] pBuffer;<br />
    return rval;<br />
}<br />

if (!AfxWinInit(::GetModuleHandle(NULL), NULL, ::GetCommandLine(), 0))
{
    _tprintf(_T("Fatal Error: MFC initialization failed\n"));
    return 1;
}

CFile logFile, dataFile;

CFileException err;

if (!dataFile.Open("e:/data.txt", CFile::modeRead | CFile::shareDenyWrite, &err))
{
    err.ReportError();
    return 1;
}

if (!logFile.Open("e:/data1.txt", CFile::modeReadWrite | CFile::modeCreate | CFile::modeNoTruncate | CFile::shareDenyWrite, &err))
{
    err.ReportError();
    return 1;
}
logFile.SeekToEnd();

int rval = 0;

int bufferLen = (int) dataFile.GetLength();
char* pBuffer = new char[bufferLen];
if (dataFile.Read(pBuffer, bufferLen) == dataFile.GetLength())
{
    logFile.Write(pBuffer, bufferLen);
}
delete [] pBuffer;
return rval;

BOOL DoesDatabaseExist(char *cpDBName, char *cpDSN, char *cpUserID, char *cpPassword)
{
  BOOL bDBExists = FALSE;

  DBConnection oDBConn;
  if (oDBConn.Connect(cpDSN,cpUserID,cpPassword))
    {
      char caBuf[256];
 
      sprintf(caBuf,"select COUNT(*) from master..sysdatabases where name = '%s'",cpDBName);
      DBStatement *pStmt = oDBConn.ExecSQL(caBuf);
      if (pStmt)
        {
          if (pStmt->FetchNext())
            bDBExists = pStmt->GetShort(1);

          pStmt->EndSQL();
          delete pStmt;
        }
      else
        DoDBError("Select Error",&oDBConn);

      oDBConn.Disconnect();
    }
  else
    DoDBError("Connection Failed!",&oDBConn);

  return bDBExists;
}

// in the *.cpp file
Foo g_SomeGlobalFoo;

// in the header file
extern Foo g_SomeGlabalFoo;