2 wk. ago • 74%

*nix doesn't make sense

imgflip.com Richard Stallman

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18 comments

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.
41
- We're talking about Unix so being as pedantic as possible is actually required.
  
  23
- 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.
  
  17
- Isn't (I|U) equivalent to ([IU])?
  
  13
  
  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.
  
  7
- at that point we could just flip the switch for the case insensitive mode
  
  7
  
  But then you'd match terms like "liNuX" and "UniX," and that's just silly. 😆
  
  7
- *nix is more likely to be a glob, therefore an accurate version would be *n?x
  
  Edit: global -> glob dang autocorrect
  
  7
- 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?
  
  3
  
  Yep, it would match LUNIX and Binux, but it would not match Bunix because of the negative lookahead.
  
  3
- _
  
  1
There's a good idea and some real potential here, but it didn't quite land for me.

3
Unix

Minix

AIX

Irix

HP/UX

Ultrix

OSF/1

Linux

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

3
- So it basically has to end with -x
  
  2
  
  ix or ux specifically.
  
  1
Isn't that the globbing operator?

2
b{2}|[^b]{2}

1
- (two B's or no two B's)
  
  2

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