How can I replace < and > in the content of xml file using regex?

Question

How can i replace a "<" and a ">" (in the content of xml file) with a matching "<" and ">" (with a pre known set of tags) using a regex?

example: <abc>fd<jkh</abc><def>e>e</def> should result with: <abc>fd<jkh</abc><def>e<e</def>

it must be done with a regex! (no xml load and such...)

this is the example which will solve all the cases. ">sdfsdf<>asdasd<>asdasdasds<" only the and the matching are predefined. — Jack, Jan 25 '10 at 19:32
-1 The failure to specify that you wanted to replace `<` and `>` on enclosed tags like `` that don't have a matching closing tag caused us to waste time on this question, which is clearly out of bounds for a reasonable regex solution. — Jay, Jan 25 '10 at 19:37
Don't do it with a regex. Regardless of your situation, you're going to run into trouble: http://stackoverflow.com/questions/701166/can-you-provide-some-examples-of-why-it-is-hard-to-parse-xml-and-html-with-a-rege — aronchick, Jan 25 '10 at 20:09

Jay · Answer 1 · 2010-01-25T19:33:11.517

2

I think the pattern

<([^>]*<)

will match a < that encounters another < before > (therefore not part of a tag)

...and the pattern

(>[^<]*)>

will match a > that follows another >

var first = Regex.Replace(@"<abc>fd<jkh</abc><def>e>e</def>",@"<([^>]*?<)",@"&lt;$1");
var final = Regex.Replace(first,@"(>[^<]*?)>",@"$1&gt;");

EDIT:

This does work, but you have to pass over it multiple times. I'm sure there's a purer method, but this does work.

class Program
{
    static void Main(string[] args)
    {
        var next = @"<abc>dffs<<df</abc>";
        string current;
        do
        {
            current = next;
            next = Regex.Replace(current, @"<([^>]*?<)", @"&lt;$1");
            next = Regex.Replace(next, @"(>[^<]*?)>", @"$1&gt;");
        } while(next != current);
        Console.WriteLine(current);
        Console.ReadKey();
    }
}

edited Jan 25 '10 at 19:33

answered Jan 25 '10 at 19:06

Jay

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@Jack you didn't give dffs< as an example. I think you should learn some RegEx so that you can take Jay's example and expand it. Remember we are supposed to point you down a path, not walk it for you. – David Basarab Jan 25 '10 at 19:17
this is my actual example, which will solve all the cases. ">sdfsdf<>asdasd<>asdasdasds<" only the and the matching are predefined. – Jack Jan 25 '10 at 19:29
this one is very good! but still didn't work with replacing the and <> ! – Jack Jan 25 '10 at 19:36

kennytm · Answer 2 · 2010-01-25T19:12:42.670

0

s/<(?=[^<>]*<)/&lt;/g
s/>(?<=\>[^<>]*)/&gt;/g

In C#,

new Regex("<(?=[^<>]*<)").Replace(your_xml_string, "&lt;");
new Regex(">(?<=\>[^<>]*)").Replace(your_xml_string, "&gt;");

Not tested. I don't have C# on my hand.

edited Jan 25 '10 at 19:12

answered Jan 25 '10 at 19:03

kennytm

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very good. but it didnt replace something like >dfddf and also didn't replace the not predifined tags like sdfsdfdasf there has to be some predefine tags... otherwise we don't get the replacement of the undefined tags... – Jack Jan 25 '10 at 19:23
@Jack: Why can't you write down all arguments at once in the question? And you can't expect to use 1 or 2 simple regex if you need to detect ``. – kennytm Jan 25 '10 at 20:24

How can I replace < and > in the content of xml file using regex?

2 Answers2

EDIT:

Linked