Improve company productivity with a Business Account.Sign Up

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 119
  • Last Modified:

How to extract an IP using "word boundary"

Hi, I have a very simple regex to find IP addresses in this format: 3.123.210.211

\d.\d\d\d.\d\d\d.\d\d\d

When presented with a string that contains something like 135.231.351.209, it will capture 5.231.351.209, but i don't want it to. I only want it to capture the IP's that come in the form x.xxx.xxx.xxx. I had a look at the "word boundary" option (\b) and it seems like it's what I need, but I'm foggy on the usage of it. Could anyone shed some light please?

Thanks
   Shawn
0
shawn857
Asked:
shawn857
  • 3
  • 2
1 Solution
 
käµfm³d 👽Commented:
I could have sworn I'd previously answered a question similar to this, but I can't find it now...  oh well  = )

You can actually match valid IP address ranges with regex. The following will do this:

\b(25[0-5]|2[0-4]\d|1\d\d|\d?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|\d?\d)){3}\b

Open in new window

0
 
käµfm³d 👽Commented:
P.S.

On second glance, based on what is in your question, you probably just need to add the word boundary token ( \b ):

\b\d.\d\d\d.\d\d\d.\d\d\d\b

Open in new window

0
 
shawn857Author Commented:
Thanks Kaufmed... so do I need a "\b" at the start of my regex and another "\b" at the end to do what I want? Doesn't this activate the "word boundary" capabilities at the beginning *and* the end? if I only want to have "word boundary" activated for the beginning, then I would just put a "\b" at the start of my regex? Or do I always have to have a "\b" on the end? I'm still a little confused about its usage.

Thanks
   Shawn
0
 
käµfm³d 👽Commented:
You don't have to have it at the end, but without it there is the possibility that you might match something more than you want. For example, if you had the following blurb:

This is a test of a paragraph that has a bunch of octets, like 1.234.567.890.123, but the octets don't represent an IP address.

Then a regex like "\b\d.\d\d\d.\d\d\d.\d\d\d" would match:

1.234.567.890

If you're sure you won't have anything like this in your text, then you don't need the trailing word boundary. It shouldn't hurt having it in there.
0
 
shawn857Author Commented:
Thanks you Kaufmed, I now have this working perfectly.

Cheers
   Shawn
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

Featured Post

The 14th Annual Expert Award Winners

The results are in! Meet the top members of our 2017 Expert Awards. Congratulations to all who qualified!

  • 3
  • 2
Tackle projects and never again get stuck behind a technical roadblock.
Join Now