URI class bug?

Ruby
1

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

2

On 6/5/07, Morgan C. [email protected] 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.

3

On Jun 5, 3:00 pm, “Jano S.” [email protected] 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

4

On Jun 5, 5:24 pm, “Jano S.” [email protected] 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 :wink:
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 :slight_smile:

5

On 6/5/07, Morgan C. [email protected] 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 = 1digit “.” 1digit “.” 1digit “.” 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 :wink:

6

Morgan C. wrote:

On Jun 5, 5:24 pm, “Jano S.” [email protected] wrote:

There’s no “_” there. YMMV :wink:

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 :slight_smile:
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?

7

On 6/5/07, Morgan C. [email protected] wrote:

uri = "http://dr_gabriele.podomatic.com/enclosure/

uri = URI.escape(original_uri)
alphanum = alpha | digit

There’s no “_” there. YMMV :wink:

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 :slight_smile:

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.