c# - .NET replace non-printable ASCII with string representation of hex code

Question

I have a string with some non-printable ascii characters in it, something like:

"ABCDx09x05
"

I want to replace these characters with a ascii string representation of the hex code numbers, so I get something like this:

"ABCD[09][05][0D][0A]"

Whats the best way to do this? Can a regex be used?

Answer 1

The pattern p{Cc} matches any control character, so

Regex.Replace(input,
              @"p{Cc}", 
              a=>string.Format("[{0:X2}]", (byte)a.Value[0])
            );

would also replace control characters.