C / C++ / MFC

_TCHAR *FileExt = new _TCHAR[10];
int FileNameLen = _tcslen(FileName);
for(int x = FileNameLen; x>= 0; x--)
{
    if(FileName[x] == _T('.'))
    {
        // Get the extension
        _tcsncpy(FileExt, FileName + x + 1, FileNameLen - x - 1);
        break;
    }
}

_tcsupr(FileExt);

if ((_tcscmp(FileExt,_T("U")) == 0) || (_tcscmp(FileExt,_T("DLL")) == 0))
{
    delete []FileExt;
    return 1;
}
else if (_tcscmp(FileExt,_T("UNR")) == 0)
{
    delete []FileExt;
    return 2;
}
else
{
    delete []FileExt;
    return 3;
}

int LookAtExt(LPCWSTR wszFilename)
{
LPCWSTR wszExt = PathFindExtension ( wszFilename );
 
  if ( 0 == _wcsicmp ( wszExt, L".U" ) || 0 == _wcsicmp ( wszExt, L".DLL" ) )
    return 1;
  else if ( 0 == _wcsicmp ( wszExt, L".UNR" ) )
    return 2;
  else
    return 3;
}