[SOLVED] what does this regular expression do?

smeezekitty · 10-07-2009, 04:31 PM

what does this do? :

Code:

[U|LI]N[U|I]X

pixellany · 10-07-2009, 04:52 PM

Well....

It depends on how it is used---right? What is it supposed to do?

smeezekitty · 10-07-2009, 04:54 PM

i really dont know
i found it when i digging thru my harddrive

pixellany · 10-07-2009, 05:04 PM

What does this mean?:
[U|LI]

and how is it different from?:
[ULI]

sycamorex · 10-07-2009, 05:20 PM

Isn't | the operator that matches either argument?

[LI|U]N - would match LIN or UN
[I|U]X - IX or UX

If I'm not mistaken, this search pattern would match either LINUX or UNIX

gzunk · 10-07-2009, 05:24 PM

And LINIX and UNUX

bgeddy · 10-07-2009, 05:27 PM

Quote:

If I'm not mistaken, this search pattern would match either LINUX or UNIX

.. and LINIX or UNUX surely ?

smeezekitty · 10-07-2009, 05:27 PM

thank you
its anoying to come by somthing but nnot know what it does

sycamorex · 10-07-2009, 05:38 PM

Quote:

Originally Posted by gzunk

And LINIX and UNUX

LOL

sycamorex · 10-07-2009, 06:02 PM

Actually, it's even worse than that. Pixellany was right.

Code:

[U|LI]N

It would match any word that contains the capital letter U or L or I followed by N. The same goes for the second part of the pattern.
For example, it would match:
ADFAEDUNFAFAFDDIX, etc.

sycamorex · 10-07-2009, 06:12 PM

Code:

bash-3.1$ ls | grep -E '[LI|U]N[U|I]X'
ADDFUNUX
INIX
LINIX
LINUX
UNIX
UNUX
UNUXFOD
bash-3.1$ ls | grep -E '(LI|U)N(U|I)X'
ADDFUNUX
LINIX
LINUX
UNIX
UNUX
UNUXFOD
bash-3.1$ ls | grep -E '^(LI|U)N(U|I)X$'
LINIX
LINUX
UNIX
UNUX
bash-3.1$ ls | grep -E '^(LINU|UNI)X$'
LINUX
UNIX