l i n u x - u s e r s - g r o u p - o f - d a v i s
L U G O D
 
Next Meeting:
November 4: Social gathering
Next Installfest:
TBD
Latest News:
Oct. 10: LUGOD Installfests coming again soon
Page last updated:
2006 Jan 30 10:23

The following is an archive of a post made to our 'vox-tech mailing list' by one of its subscribers.

Report this post as spam:

(Enter your email address)
Re: [vox-tech] Regexp question
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [vox-tech] Regexp question



Ken Herron wrote:
> Ken Bloom wrote:
> 
>> How can I match, in one regexp strings that begin with "att_" but do not
>> begin with "att_appraisal"?
> 
> 
> In perl or something with perl's regexp capabilities, you'd use a
> negative lookahead:
> 
>     ^att_(?!appraisal)

irb(main):001:0> "att_products".match(/^att_(?!appraisal)/)
=> #<MatchData:0xb7cf80c4>
irb(main):002:0> "att_appraisal".match(/^att_(?!appraisal)/)
=> nil

Works like a charm in Ruby. Thanks!

> Without that, your best bet is to combine two regexps using boolean logic:
> 
>     if (/^att_/ && !/^att_appraisal/)

This is what I changed it to before sending the message.

> You could do this with one regexp but it's ugly:
> 
>     ^att_($|[^a]|a($|[^p]|p($|[^p]|p($[^r]|...
> 
> i.e., "att_" followed by end-of-string OR not-a OR a followed by (end of
> string OR not-p OR p followed by..

I thought of that, but I *most definitely* wasn't going to try it.

Thanks

--Ken

-- 
I usually have a GPG digital signature included as an attachment.
See http://www.gnupg.org/ for info about these digital signatures.

Attachment: signature.asc
Description: OpenPGP digital signature

_______________________________________________
vox-tech mailing list
vox-tech@lists.lugod.org
http://lists.lugod.org/mailman/listinfo/vox-tech


LinkedIn
LUGOD Group on LinkedIn
Sign up for LUGOD event announcements
Your email address:
facebook
LUGOD Group on Facebook
'Like' LUGOD on Facebook:

Hosting provided by:
Sunset Systems
Sunset Systems offers preconfigured Linux systems, remote system administration and custom software development.

LUGOD: Linux Users' Group of Davis
PO Box 2082, Davis, CA 95617
Contact Us

LUGOD is a 501(c)7 non-profit organization
based in Davis, California
and serving the Sacramento area.
"Linux" is a trademark of Linus Torvalds.

Sponsored in part by:
Appahost Applications
For a significant contribution towards our projector, and a generous donation to allow us to continue meeting at the Davis Library.