this post was submitted on 05 Oct 2024
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Linux

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From Wikipedia, the free encyclopedia

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

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[–] [email protected] 41 points 1 month ago* (last edited 1 month ago) (7 children)

Because there's non-programmers in this community, if you aren't sure what this means but are too afraid to ask, it's a Regular Expression that better represents the terms "Linux" and "Unix."

Though if we're going to be that pedantic, it would be [nN][uiI][xX]$. That extra pipe wouldn't actually do anything in the last example, because regexp picks one character from the set by default.

And if we want to be really pedantic,

(?!nix)[nN][uI][xX]$

Would be the most accurate.

Edit: based on comments, I think...

(nux|NIX)$

...would be the best. Then you don't wind up with weird matches with things like UNiX.

[–] [email protected] 23 points 1 month ago

We're talking about Unix so being as pedantic as possible is actually required.

[–] [email protected] 17 points 1 month ago

Actually *nix isn't a Regular Expression, because the star operator * requires a preceding character or object to apply to. This is a wildcard for the shell style globbing, where a single star doesn't require a second object.

[–] [email protected] 13 points 1 month ago (1 children)

Isn't (I|U) equivalent to ([IU])?

[–] [email protected] 7 points 1 month ago

Yes, but you can really only do that with single characters, since your first example is an ordered group and the second is an unordered set in a capturing group. The equivalency drops off when you include more characters.

Plus, you can do things like [a-zA-Z], and you can't do that with the former example.

I would imagine there's a difference in computing overhead, too, but I have no idea which is more performant.

[–] [email protected] 7 points 1 month ago (1 children)

at that point we could just flip the switch for the case insensitive mode

[–] [email protected] 7 points 1 month ago (1 children)

But then you'd match terms like "liNuX" and "UniX," and that's just silly. 😆

[–] [email protected] 4 points 1 month ago (1 children)

The pattern they made already does that though lmao.

[–] [email protected] 1 points 1 month ago

That's true! Good catch. Regexp is a fun challenge.

[–] [email protected] 7 points 1 month ago* (last edited 1 month ago)

*nix is more likely to be a glob, therefore an accurate version would be *n?x

Edit: global -> glob dang autocorrect

[–] [email protected] 3 points 1 month ago* (last edited 1 month ago) (1 children)

All that effort, when you could've just called it LUNIX.

By the way, does this expression match LUNIX? But if so, won't it also match Binux or Bunix?

[–] [email protected] 3 points 1 month ago

Yep, it would match LUNIX and Binux, but it would not match Bunix because of the negative lookahead.

[–] [email protected] 3 points 1 month ago* (last edited 1 month ago) (1 children)

Unix

Minix

AIX

Irix

HP/UX

Ultrix

OSF/1

Linux

Those are just the ones I remember because I've used them

[–] [email protected] 2 points 1 month ago (1 children)

So it basically has to end with -x

[–] [email protected] 1 points 1 month ago

ix or ux specifically.

[–] [email protected] 3 points 1 month ago

There's a good idea and some real potential here, but it didn't quite land for me.