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Match and replace

Juan | Last updated: Jul 13, 2017 02:32AM UTC

Hello. How do I write a newline character in the Replace field, in "Match and Replace"? Which kind of notation is used? Is there any list of examples? Thanks in advance.

PortSwigger Agent | Last updated: Jul 13, 2017 07:20AM UTC

This isn't directly supported, but there is a workaround. Create your match and replace rule with an X where you want your newline. Click the cog icon and save the options. Then edit this JSON file and replace X with \r\n When you reload the options you will have a newline in your rule. Please let us know if you need any further assistance.

PortSwigger Agent | Last updated: Jul 13, 2017 07:23AM UTC

Hi Juan, Please follow the instructions I provided. They work fine on Burp Free for me.

Burp User | Last updated: Jul 14, 2017 10:04PM UTC

As I am using the free version, the rule is in registry, stored in HKCU\Software\JavaSoft\Prefs\burp\1.5free.proxy.matchreplacerule5 key. I tried what you suggested but it does not work. During execution, the replacement removes the slashes and keeps "rn" as if it were a normal string. Thank you very much.

PortSwigger Agent | Last updated: Jul 17, 2017 07:30AM UTC

Hi Juan, I've attached a couple of screenshots that show you how to save the JSON file. Burp uses Java regular expressions. This cheat sheet may help you: - http://www.omicentral.com/cheatsheets/JavaRegularExpressionsCheatSheet.pdf

Burp User | Last updated: Jul 19, 2017 11:44PM UTC

Thank you very much Paul. I was careful and did what you told me. I have no JSON file, only the key I mentioned, in the registry. And the result is as if the backslashes weren't there (I get the rn substring instead of a newline character). I am trying a replacement in the response body. Is there any document about the syntax of the "regular expressions" Burp use?

Burp User | Last updated: Jul 20, 2017 11:51PM UTC

Thank you very much Paul! I really appreciate your help. I updated to 1.7.23 version and studied the sheet. With kind regards, Juan

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