/// <summary>
        /// Byte array to be used by FindPattern
        /// </summary>
        private static byte[] _file;
        /// <summary>
        /// Finds a specific pattern in a byte array
        /// </summary>
        /// <param name="btPattern">Byte array containing pattern to search</param>
        /// <param name="strMask">x for exact match, ? for wildcard</param>
        /// <returns>Position of pattern in _file, -1 if pattern not found</returns>
        public static int FindPattern(byte[] btPattern, string strMask)
        {
            try
            {
                if (strMask.Length != btPattern.Length)
                    return -1;
                for (int x = 0; x < _file.Length; x++)
                {
                    if (MaskCheck(x, btPattern, strMask))
                    {
                        return x;
                    }
                }
                return -1;
            }
            catch (Exception ex)
            {
                return -1;
            }
        }

        private static bool MaskCheck(int nOffset, byte[] btPattern, string strMask)
        {
            return !btPattern.Where((t, x) => strMask[x] != '?' && ((strMask[x] == 'x') && (t != _file[nOffset + x]))).Any();
        }