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From: Pancho <Pancho.Jones@protonmail.com>
Newsgroups: comp.os.linux.misc
Subject: Re: Useless Use Of Regexes
Date: Mon, 24 Mar 2025 21:48:26 +0000
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On 3/24/25 20:34, Lawrence D'Oliveiro wrote:
> Besides the traditional “Useless Use Of Cat” (UUOC) newbie faux pas,
> we can add “Useless Use Of Regexes”.
> 
> These can often be quite subtle. I spotted one obvious instance here
> <https://www.zdnet.com/article/5-ways-i-use-regex-in-linux-and-why-theyre-so-essential/>,
> namely this one:
> 
>      ip addr | grep -Eo '192\.168\.1\.[0-9]{1,3}'
> 


Tut Tut!

$ip addr | grep -E '192\.168\.0\.([0-1]?[0-9]?[0-9]?|2[0-4][0-9]|25[0-5])'

Solve a problem with a RegEx, now you have two problems :-)


> which can be more easily written using features built into iproute2 itself:
> 
>      ip addr show to 192.168.1.0/24

Seriously, though, it is often easier to filter output from a standard 
command with grep, than it is to learn all the command flags.