I've such kind of strings from the log file

rule family="ipv4" source address="" reject
rule family="ipv4" source address="" reject

How can I match an IP address from every of that string and then replace the original one with matched IP using regular expression in Notepad++ text editor?

Expected result:

I prefer to achieve the goal usig regexp and Search and replace only. If it ever possible in Notepad++ I know that I can use macro functionality, but I don't want to do so.

So, at first, we'll match IP with regexp (\d{1,3}.\d{1,3}.\d{1,3}.\d{1,3}). At second we replace original string with IP from step #1 But I'm not sure if it ever possible using Notepad++. If I'm failed with this, I'll use vim :-)

  • If text rule family="ipv4" source address=" is common in all lines, you can also replace your IP by recording a macro for one row and executing it till end of file. – Sandeep May 10 '18 at 8:11
  • It's not really clear what you are trying to achieve, please, edit your question and add more lines and expected result. – Toto May 10 '18 at 8:14
  • @Toto, Example added, done. – Twissell May 10 '18 at 11:49
  • Ctrl+H
  • Find what: ^.+?((?:\d+\.){3}\d+).+$
  • Replace with: $1
  • check Wrap around
  • check Regular expression
  • DO NOT CHECK . matches newline
  • Replace all


^           : beginning of line
.+?         : 1 or more any character but newline
(           : start group 1
  (?:       : start non capture group
    \d+     : 1 or more digit
    \.      : a dot
  ){3}      : end group, must appear 3 times
  \d+       : 1 or more digit
)           : end group 1
.+          : 1 or more any character but newline
$           : end of line


$1          : content of group 1 (ie. the IP)

Result for given example:

To be sure you have an IP address, use


instead of

  • That's what I want. Thanks! I used a very similar to your regexp, but my mistake was checked matched newline box – Twissell May 10 '18 at 12:35

Simpler solution, but not using RegEx:


rule family="ipv4" source address="

with nothing, and

" reject

with nothing.

  • Thanks for your reply. But it is trick but not truth approach , IMHO – Twissell May 10 '18 at 14:14

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