grep expression (perl regex) to extract all ip addresses from both ip and ifconfig commands output

ip a | grep -oP '(?<=inet |addr:)(?:\d+\.){3}\d+'
It uses the following GNU grep options: "-o" which shows only the matching part of the line and "-P" which allows the use of Perl regular expressions.
Sample Output
[root@docker ~]# ip a | grep -oP '(?<=inet |addr:)(?:\d+\.){3}\d+'

[root@docker ~]# ifconfig  | grep -oP '(?<=inet |addr:)(?:\d+\.){3}\d+'

By: acavagni
2019-03-21 20:53:06

What Others Think

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HayleyRice · 39 weeks and 5 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?

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