How to search a document for IP addresses [closed]

Question

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.

Closed 9 years ago.

So I have a document (plain text) that I'm trying to extract all of the IP addresses from. I was able to extract them using regular expressions but it also grabs a large number of version numbers. I tried using string.find() but it requires that I be able to locate the escape character used for the end of the line (the IP addresses are always the last thing on a line) and the escape character used for the end of the line is unknown to me. Anyone know how I could pull these addresses out?

Answer 1

If your addresses are always on the end of a line, then anchor on that:

ip_at_end = re.compile(r'(?:[0-9]{1,3}\.){3}[0-9]{1,3}$', re.MULTILINE)

This regular expression only matches dotted quads (4 sets of digits with dots in between) at the end of a line.

Demo:

>>> import re
>>> ip_at_end = re.compile(r'(?:[0-9]{1,3}\.){3}[0-9]{1,3}$', re.MULTILINE)
>>> example = '''\
... Only addresses on the end of a line match: 123.241.0.15
... Anything else doesn't: 124.76.67.3, even other addresses.
... Anything that is less than a dotted quad also fails, so 1.1.4
... does not match but 1.2.3.4
... will.
... '''
>>> ip_at_end.findall(example)
['123.241.0.15', '1.2.3.4']

Answer 2

Description

this will match and validate ipv4 addresses, and will ensure the individual octects are within a range of 0-255

(?:([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])

Disclaimer

yes I realize the OP asked for a Python solution. This PHP solution is only included to show how the expression works

php example

<?php
$sourcestring="this is a valid ip 12.34.56.78
this is not valid ip 12.34.567.89";
preg_match_all('/(?:(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}(?:[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])/i',$sourcestring,$matches);
echo "<pre>".print_r($matches,true);
?>

$matches Array:
(
    [0] => Array
        (
            [0] => 12.34.56.7
        )

)