System.ParseNumbers.ConvertToBase8 C# (CSharp) Method

		static StringBuilder ConvertToBase8 (byte[] value)
		{
			ulong l = 0;
			switch (value.Length) {
			case 1:
				l = (ulong) value [0];
				break;
			case 2:
				l = (ulong) BitConverter.ToUInt16 (value, 0);
				break;
			case 4:
				l = (ulong) BitConverter.ToUInt32 (value, 0);
				break;
			case 8:
				l = BitConverter.ToUInt64 (value, 0);
				break;
			default:
				throw new ArgumentException ("value");
			}

			StringBuilder sb = new StringBuilder ();
			for (int i = 21; i >= 0; i--) {
				// 3 bits at the time
				char val = (char) ((l >> i * 3) & 0x7);
				if ((val != 0) || (sb.Length > 0)) {
					val += '0';
					sb.Append (val);
				}
			}
			return sb;
		}