Question

How do i convert a value given as a hexadecimal string to an Octal format, when the number is too large to fit in a 64 bits number?

I currently convert a byte array to hex like this

Byte[] data = { 116, 4, 228, 18, 189, 145, 31, 7, 123, 74, 174, 151, 54, 144, 224, 49, 210, 169, 43, 213 };
hex = BitConverter.ToString(data).Replace("-", string.Empty);

Output in Hex:

7404E412BD911F077B4AAE973690E031D2A92BD5

How do I get the Octal representation?

So i tried this earlier, but it doesn’t work.

string binaryval = "";


  binaryval = Convert.ToString(Convert.ToInt32(hexValue,16), 8);

    foreach (char ch in hexValue)
    {

           binaryval += Convert.ToString(Convert.ToInt32(ch.ToString(), 16), 8);

    }

Answer 1

Byte[] data = { 116, 4, 228, 18, 189, 145, 31, 7, 123, 74, 174, 151, 54, 144, 224, 49, 210, 169, 43, 213};
var str = String.Join("", data.Select(b => Convert.ToString(b,8).PadLeft(3,'0')));

–

//First hex string to byte array
string hex = "7404E412BD911F077B4AAE973690E031D2A92BD5";
List<byte> buf = new List<byte>();
for (int i = 0; i< hex.Length / 2; i++) 
     buf.Add(Convert.ToByte(hex.Substring(i * 2, 2), 16));

//Then to octal as above
var str = String.Join("", buf.Select(b => Convert.ToString(b,8).PadLeft(3,'0')));