.NET replace non-printable ASCII with string representation of hex code
I have a string with some non-printable ascii characters in it, something like:
"AB开发者_JAVA技巧CD\x09\x05\r\n"
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?
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.
string s = "ABCD\x09\x05\r\n";
var replace =
s.Select(c => Char.IsControl(c) ? ((int)c).ToString("X2") : c.ToString())
.Aggregate(new StringBuilder(), (sb, t) => sb.Append(t))
.ToString();
Sorry, no compiler handy, but I think this compiles and does the job.
Also, this kind of walks the string twice (once to project each character to a hex replacement or a string, and then again to aggregate), and you can avoid this by lumping the projection into the call to Enumerable.Aggregate
, but this is more clear and it probably doesn't matter that much unless this is performance-critical.
Inspired by Jason's example, but a bit simpler. I'm not sure which performs better, and don't have the time to benchmark it right now, but it should do everything in just one pass:
string s = "ABCD\x09\x05\r\n";
string replace = String.Concat(s.Select(c => Char.IsControl(c) ?
String.Format("[{0:X2}]", (int)c) :
c.ToString()));
I've tested this for functionality.
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