using System;
using System.Text.RegularExpressions;
 
public class Test {
	public static MatchCollection getPrintableChars(string haystack) {
		var regex = new Regex(@"[^\p{Cc}^\p{Cn}^\p{Cs}]");
		var matches = regex.Matches(haystack);
		return matches;
	}
	public static void Main() {
		var teststring1 = "Hello, World!";
		var teststring2 = "Hello, World!" + (char)4;
 
		var teststring1unprintablechars = getPrintableChars(teststring1);
		var teststring2unprintablechars = getPrintableChars(teststring2);
 
		Console.WriteLine("Testing a Printable String: " + teststring1unprintablechars.Count + " Printable Chars Detected");
		Console.WriteLine("Testing a String With 1-Unprintable Char: " + teststring2unprintablechars.Count + " Printable Chars Detected");
 
		foreach (Match unprintablechar in teststring1unprintablechars) {
			Console.WriteLine("String 1 Printable Char:" + unprintablechar);
		}
 
		foreach (Match unprintablechar in teststring2unprintablechars) {
			Console.WriteLine("String 2 Printable Char:" + unprintablechar);
		}
	}
}
 

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