From: Kendall Gifford <zettabyte@...>
Date: 2011-07-23T04:08:20+09:00
Subject: Re: Regexp inconsistency

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On Fri, Jul 22, 2011 at 12:42 PM, Carlos Camargo <camargo.cr@gmail.com>wrote:

> I observed a inconsistent behavior between ruby (ruby 1.8.6 (2009-06-08
> patchlevel 369) [x86_64-linux]), running in my host, and ruby in
> www.rubular.com (reports "Rubular runs on Ruby 1.8.7."). The expression:
> / (\w+(\-\w+)?) \. (log|txt) [\.\-]? (\d{1}) ( \. (gz|bz2))? /x
> in my host returns (among others):
> net-snmpd.log-20110629.bz2
>

I just matched "net-snmpd.log-20110629.bz2 stuff blah blah" against that
regex in 1.8.6-p420:

> regex.match(string)[0] => "net-snmpd.log-2"

This seems correct to me. In the area of your regex: " (\d{1}) (\.
(gz|bz1))? " you explicitly match exactly one digit (which could also be
accomplished by omitting the curly-brace quantifier.

If you want it to match all following digit (1 more more) you could use:
\d{1,} or more commonly \d+


> In rubular site, recognize (correctly, I suppose!) just until:
> net-snmpd.log-2 (stop here, i.e. don't recognize the string).
>

It recognizes it. Your file extension is optional (? quantifier around
group). Again, this behavior matches my system's ruby 1.8.6 implementation
as well as how it *should* behave, given your regex.


>
> Thanks for any help! (Upgrade ruby to 1.9 isn't an option!)
> Camargo
>

How about: / (\w+(\-\w+)?) \. (log|txt) [\.\-]? (\d+) ( \. (gz|bz2))? /x


>
> NB: My code (just for test) is:
> #! /usr/bin/ruby -w
>
> require 'find'
>
> re_logdir = Regexp.new(/\/log$|\/log\/|\/logs$|\/logs\//)
> dias = 5
>
> ###
> a='(\w+(\-\w+)?)'
> d='(\d{4}[\.\-]?\d{2}[\.\-]?\d{2})'
> h='(\d{2}[\.\-]?\d{2}[\.\-]?\d{2,6})'
> l='(log|txt)'
> z='(gz|bz2)'
> n1='(\d{1})'
> s='[\.\-]'
>

So change n1 to: '(\d+)'


>
> re_logfile = Regexp.new(/ #{a} \. #{l} #{s}? #{n1} ( \. #{z})? /x )
> p re_logfile
>
> Find.find('/') do |f|
>  if File.file?(f) and
>     re_logdir.match( File.dirname(f) ) and
>     re_logfile.match( File.basename(f) )
>     p f
>  end
> end
>
> --
> Posted via http://www.ruby-forum.com/.
>
>


-- 
Kendall Gifford
zettabyte@gmail.com

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