Get nodes from xml string using regex

Question

I have string xml like below:

<Query>
  <Code>USD</Code>
  <Description>United States Dollars</Description>
  <UpdateTime>2013-03-04 02:27:33</UpdateTime>
  <toUSD>1</toUSD>
  <USDto>1</USDto>
  <toEUR>2</toEUR>
  <EURto>3</EURto>
</Query>

All text is in one line without white spaces. I can't write right regex pattern. I want get nodes which begin like <to. For example <toEUR>, <toUSD>.

How should I write this pattern?

[Please don't use RegEx for XML](http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags) — CAMOBAP, Mar 04 '13 at 16:40
Which language? It would be better to use an actual XML library (or xpath, or anything but regex). — Cᴏʀʏ, Mar 04 '13 at 16:41
In Ruby. For me that is a short plain text, so I decide to use regex. — user1931951, Mar 04 '13 at 17:00
@user1931951: A few options: http://developer.yahoo.com/ruby/ruby-xml.html — Cᴏʀʏ, Mar 04 '13 at 17:12
Even for simple(-looking) regex/XML IMO it's almost never worth it since there are many options available. — Dave Newton, Mar 04 '13 at 17:14

score 0 · Answer 1 · answered Mar 05 '13 at 05:46

With nokogiri and the xpath function starts-with:

require 'nokogiri'
doc = Nokogiri::XML <<EOF
<Query>
  <Code>USD</Code>
  <Description>United States Dollars</Description>
  <UpdateTime>2013-03-04 02:27:33</UpdateTime>
  <toUSD>1</toUSD>
  <USDto>1</USDto>
  <toEUR>2</toEUR>
  <EURto>3</EURto>
</Query>
EOF

doc.search('//*[starts-with(name(),"to")]').map &:to_s
#=> ["<toUSD>1</toUSD>", "<toEUR>2</toEUR>"]

rvalvik · Answer 2 · 2013-03-05T07:37:19.617

-1

Although the general consensus is that parsing xml etc with regex is not the way to go, something like this should do the trick:

<\s*(to[^>\s]+)[^>]*>([^<]+)<\s*/\s*\1\s*>

In ruby format:

/<\s*(to[^>\s]+)[^>]*>([^<]+)<\s*\/\s*\1\s*>/

Matches <toWatever>value</toWhatever> back-reference group 1 returns the name (toWhatever) and back-reference group 2 returns the value.

edited Mar 05 '13 at 07:37

answered Mar 04 '13 at 22:48

rvalvik

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Get nodes from xml string using regex

2 Answers2