egrep -o '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' file.txt

Filter IPs out of files


4
By: P17
2009-05-28 14:46:17

These Might Interest You

What Others Think

egrep -wo '([0-9]{1,3}\.){3}[0-9]{1,3}' file.txt selects on word boundaries and is slightly less verbose
kiwi · 468 weeks and 3 days ago
cool didn't know about the -o option ....
copremesis · 468 weeks and 3 days ago
perl version: perl -ne's/(\d{1,3}\.){3}\d{1,3}/print"$&\n"/ge' file.txt and, perl version (word boundary): perl -ne's/\b(\d{1,3}\.){3}\d{1,3}\b/print"$&\n"/ge' file.txt
wbx · 468 weeks and 3 days ago
This is all *plain wrong*, you extract 4 numbers (Each up to three digits) seperated by dots with these regexes. These numbers don't have to be valid IPs. See: echo "999.999.999.999" > file.txt echo "10.1.12.23" >> file.txt perl -ne's/(\d{1,3}\.){3}\d{1,3}/print"$&\n"/ge' file.txt 999.999.999.999 10.1.12.23 egrep -o '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' file.txt 999.999.999.999 10.1.12.23 Better use sth. like that (Not mine, found with google): egrep '\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b' file.txt 10.1.12.23
OJM · 468 weeks and 2 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

You must be signed in to comment.

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands



Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: