Re: Filtering out IP addresses

This'll do it:

$ perl -nle 's/([0-9]?\d\d?|2[0-4]\d|25[0-5])\.([0-9]?\d\d?|2[0-4]\d|2
+5[0-5])\.([0-9]?\d\d?|2[0-4]\d|25[0-5])\.([0-9]?\d\d?|2[0-4]\d|25[0-5
+])/xxx.xxx.xxx.$4/; print' filename
[download]

Depending on what your file contains, this can be simplified a lot, though. If it's e.g. one IP address per line, the following will also be fine:

$ perl -nle 's/\d+\./xxx./g; print' filename
[download]

But in the presence of other data, it may or may not work as intended, and also note it neither cares about IP addresses having four fields, nor about each field ranging from 0 to 255, or in fact consisting of no more than three decimal digits.

When in doubt, I'd suggest using the first one, even if it's a bit unwieldy.

Comment on Re: Filtering out IP addresses Select or Download Code

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Re^2: Filtering out IP addresses by kennethk (Abbot) on Jul 22, 2014 at 22:01 UTC
`perl -nle 's/\d+\./xxx./g; print' filename` [download] As long we're writing one-liners, that should probably be `perl -ple 's/\d+\./xxx./g' filename` [download] See -p in perlrun. #11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.	[reply] [d/l] [select]
Re^3: Filtering out IP addresses by AppleFritter (Vicar) on Jul 22, 2014 at 22:06 UTC
Oh, nice, I'd not been aware of `-p` yet. Thanks for the pointer!	[reply]
Re^2: Filtering out IP addresses by Anonymous Monk on Jul 23, 2014 at 15:18 UTC
thank you, that was a really helpful answer. We need People like you who take time of their day to help a stranger. Perl monk is the best!	[reply]
Re^3: Filtering out IP addresses by AppleFritter (Vicar) on Jul 23, 2014 at 16:30 UTC
Awww shucks, sugarcube. tips hat You're very welcome!	[reply]