Regular Expressions to remove or replace

Solution Title: Regular Expressions to remove or replace Author: pmengal Points: 500   Grade: A Date: 05/12/2003 01:18AM PDT

Hello, I want to use a regular expression to replace or remove some texts. Replace ------- I want to be able to replace > by &gt; in the following HTML text : "<p><strong>Superman is greater > than Spiderman</strong></p>" The same code should work also for this text without any change : "<span class="thisname<isinvalid"><b>a > b ?</b></span>" You understood, it's to use with a custom Html Encoder. Remove ------ I want to remove all (tags included) that is between <script></script> like : "<script> some malicious code </script>" The same code (without any change, but different that the replace one of course) should work on this too : "<script language="javascript"> some malicious code </script>" and this one "<script language='javascript'> some malicious code </script>" and this one too "<script dull="dull" language="javascript"> some malicious code</script>" and this one too ... "<SCRIPT Language="JavaScript"> some malicious code </ScripT>" Sorry to be so complete, but I posted some 500 and 250 questions and got incomplete answers due to the non complete enough question. Thanks in advance !

Comment from pmengal Date: 05/12/2003 01:19AM PDT	Author Comment
Forgot to say : Can you provide ALL the code to achieve this ? Giving me just the regular expression will not help me. I'm not familiar with regular expressions at all... If you have time, giving me some website to learn is welcome
Comment from AvonWyss Date: 05/12/2003 05:22AM PDT	Comment
I will.... stay tuned.
Comment from testn Date: 05/12/2003 06:37AM PDT	Comment
Hi, my previous regex should work with > pattern = "((?<!(<([^>])*))(>))|((?<=((<(\/)?[^A-Z,a-z,/,]){1}([^>,<])*))(>))" About tutorials, http://www.c-sharpcorner.com/3/RegExpPSD.asp http://www.wellho.net/regex/dotnet.html http://windows.oreilly.com/news/csharp_0101.html If you want a comprehensive book, you might consider buying pdf from amazon http://www.amazon.com/exec/obidos/tg/detail/-/B0000632ZU/102-4200309-1247344?vi=glance
Accepted Answer from testn Date: 05/12/2003 06:42AM PDT	Accepted Answer
This is the code for removing malicious code. using System.Text.RegularExpressions; public string removeMaliciousCode(string oldStr) {           string pattern = @"(?i)<script([^>])*>(\w|\W)*</script([^>])*>";           string newStr  = Regex.Replace(oldStr,pattern,"");                 return newStr; } This function will return the string that contains no malicious code.
Comment from testn Date: 05/12/2003 06:47AM PDT	Comment
Explain the function...... (?i) means case-insensitive string matching <script([^>])*> means finding any string starting with "<script" and contains 0 or more characters before ending with > (\w|\W)* means may having some string in between <Script> and </script> (0 or more characters of anything) </script([^>])*>" means finding any string starting with "</script" and contains 0 or more characters before ending with > However, this one may be too extreme since it will also match the whole string of <SCRIPT Language="JavaScript"> some malicious code</ScripT> Hello <script ></script> without leaving Hello
Comment from testn Date: 05/12/2003 07:22AM PDT	Comment
You can make it better by putting <script[^>]*>.*?</script[^>]*> It will screen <SCRIPT Language="JavaScript"> some malicious code</ScripT> Hello <script ></script> without to Hello since .*? mean non-greedy matching it will try to match up least possible characters of the pattern
Comment from testn Date: 05/12/2003 07:33AM PDT	Comment
Please also keep testing when this applies to multiple lines data You might need to change it to <script[^>]*>(\w|\W)*?</script[^>]*> or to (?m)<script[^>]*>(\w|\W)*?</script[^>]*>
Comment from AvonWyss Date: 05/12/2003 09:39PM PDT	Comment
private string ReplaceMatch(Match match) {                if (match.Groups["script"].Success)                     return "";                else if (match.Groups["gt"].Value==">")                     return "&gt;";                else                     return match.Value;           }                     public string CleanupHtml(string html) {                return Regex.Replace(html, @"(?<script><script[^>]*>.*?</script[^>]*>)|(?<gt>(<(""[^""]""|'[^']'|[^>])+)?>)", new MatchEvaluator(ReplaceMatch), RegexOptions.ExplicitCapture|RegexOptions.IgnoreCase|RegexOptions.Singleline);           } This Regex will do both your tasks and at the same time. The first part is pretty similar to testn's suggestion, but I also provide the code to find single > chars (with no matching < before).
Comment from osxmaster Date: 02/23/2004 02:19PM PST	Comment
Hi do you know how I can clean this page from HTML and script tags? http://www.wipo.org Seems to be very complicated. thanks
Comment from AvonWyss Date: 02/24/2004 09:59PM PST	Comment
Yes I do. Just a few days ago I answered a very similar question; have a look at recent posts in C# http:Q_20892954.html Or you can of course also post a new Q.