Forum: Ruby URI class bug?

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E15af4b1b2bd121942572a8b981ef84c?d=identicon&s=25 Morgan Cheng (Guest)
on 2007-06-05 08:35
(Received via mailing list)
I am using Ruby 1.8.6. I found URI cannot parse URI with "_" is host.

uri = "http://dr_gabriele.podomatic.com/enclosure/
2006-08-03T15_09_59-07_00.m4v"
URI.parse(uri)

Is there any way to work around that?
thanks
97550977337c9f0a0e1a9553e55bfaa0?d=identicon&s=25 Jano Svitok (Guest)
on 2007-06-05 09:01
(Received via mailing list)
On 6/5/07, Morgan Cheng <morgan.chengmo@gmail.com> wrote:
> I am using Ruby 1.8.6. I found URI cannot parse URI with "_" is host.
>
> uri = "http://dr_gabriele.podomatic.com/enclosure/
> 2006-08-03T15_09_59-07_00.m4v"
> URI.parse(uri)
>
> Is there any way to work around that?
> thanks

It seems underscores are not allowed in host part of an URI. So it's
not a bug. See RFC 2396 (URI),  and 1035 (DNS). If you really want it,
you can open the class and redefine some of the methods and/or
manually edit URI sources.
E15af4b1b2bd121942572a8b981ef84c?d=identicon&s=25 Morgan Cheng (Guest)
on 2007-06-05 09:41
(Received via mailing list)
On Jun 5, 3:00 pm, "Jano Svitok" <jan.svi...@gmail.com> wrote:
>
> It seems underscores are not allowed in host part of an URI. So it's
> not a bug. See RFC 2396 (URI),  and 1035 (DNS). If you really want it,
> you can open the class and redefine some of the methods and/or
> manually edit URI sources.


In RFC 2396, "_" is taken as "Unreserved Characters".
   Unreserved characters can be escaped without changing the semantics
   of the URI, but this should not be done unless the URI is being
used
   in a context that does not allow the unescaped character to appear.

However, URI.escape doesn't escape "_".

require 'URI'
original_uri = "http://dr_gabriele.podomatic.com/enclosure/"
uri = URI.escape(original_uri)
puts uri == original_uri
97550977337c9f0a0e1a9553e55bfaa0?d=identicon&s=25 Jano Svitok (Guest)
on 2007-06-05 11:24
(Received via mailing list)
On 6/5/07, Morgan Cheng <morgan.chengmo@gmail.com> wrote:
> > > thanks
> used
>    in a context that does not allow the unescaped character to appear.
>
> However, URI.escape doesn't escape "_".
>
> require 'URI'
> original_uri = "http://dr_gabriele.podomatic.com/enclosure/"
> uri = URI.escape(original_uri)
> puts uri == original_uri

I'm no expert on DNS, this is what I have found in appendix A:

host          = hostname | IPv4address
hostname      = *( domainlabel "." ) toplabel [ "." ]
domainlabel   = alphanum | alphanum *( alphanum | "-" ) alphanum
toplabel      = alpha | alpha *( alphanum | "-" ) alphanum
IPv4address   = 1*digit "." 1*digit "." 1*digit "." 1*digit

alphanum      = alpha | digit
alpha         = lowalpha | upalpha

lowalpha = "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" | "i" |
             "j" | "k" | "l" | "m" | "n" | "o" | "p" | "q" | "r" |
             "s" | "t" | "u" | "v" | "w" | "x" | "y" | "z"
upalpha  = "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" |
             "J" | "K" | "L" | "M" | "N" | "O" | "P" | "Q" | "R" |
             "S" | "T" | "U" | "V" | "W" | "X" | "Y" | "Z"
digit    = "0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" |
             "8" | "9"

There's no "_" there. YMMV ;-)
E15af4b1b2bd121942572a8b981ef84c?d=identicon&s=25 Morgan Cheng (Guest)
on 2007-06-05 11:51
(Received via mailing list)
On Jun 5, 5:24 pm, "Jano Svitok" <jan.svi...@gmail.com> wrote:
> > > > 2006-08-03T15_09_59-07_00.m4v"
> > In RFC 2396, "_" is taken as "Unreserved Characters".
> > puts uri == original_uri
> alpha         = lowalpha | upalpha
> There's no "_" there. YMMV ;-)
Thanks a lot for your help.

I am just wandering, internet is a wild world. Wierd non-standard
stuff is all around. The non-standard host name is a example. Popular
browser can handle these URLs well.
Perhaps ruby should be more strong to survive better in such wild
world :-)
Ad7805c9fcc1f13efc6ed11251a6c4d2?d=identicon&s=25 Alex Young (regularfry)
on 2007-06-05 13:13
(Received via mailing list)
Morgan Cheng wrote:
> On Jun 5, 5:24 pm, "Jano Svitok" <jan.svi...@gmail.com> wrote:
<snip>
>> There's no "_" there. YMMV ;-)
>
> Thanks a lot for your help.
>
> I am just wandering, internet is a wild world. Wierd non-standard
> stuff is all around. The non-standard host name is a example. Popular
> browser can handle these URLs well.
> Perhaps ruby should be more strong to survive better in such wild
> world :-)
There was mention a few days ago of bringing the URI class up to a more
recent RFC compliance (3986, I think).  Would that help in this
instance?
97550977337c9f0a0e1a9553e55bfaa0?d=identicon&s=25 Jano Svitok (Guest)
on 2007-06-05 13:14
(Received via mailing list)
On 6/5/07, Morgan Cheng <morgan.chengmo@gmail.com> wrote:
> > > > > uri = "http://dr_gabriele.podomatic.com/enclosure/
> >
> > > uri = URI.escape(original_uri)
> > alphanum      = alpha | digit
> >
> > There's no "_" there. YMMV ;-)
>
> Thanks a lot for your help.
>
> I am just wandering, internet is a wild world. Wierd non-standard
> stuff is all around. The non-standard host name is a example. Popular
> browser can handle these URLs well.
> Perhaps ruby should be more strong to survive better in such wild
> world :-)

If you want to really use underscores, modify lib/1.8/uri/common.rb:
add the following after line HOSTNAME=... and comment out (prefix with
#) the original HOSTNAME line.

      ALPHA_ = "a-zA-Z_"
      ALNUM_ = "#{ALPHA_}\\d"
      DOMLABEL_ = "(?:[#{ALNUM_}](?:[-#{ALNUM_}]*[#{ALNUM_}])?)"
      TOPLABEL_ = "(?:[#{ALPHA_}](?:[-#{ALNUM_}]*[#{ALNUM_}])?)"
      HOSTNAME = "(?:#{DOMLABEL_}\\.)*#{TOPLABEL_}\\.?"

J.
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