Nokogiri (鋸) is an HTML, XML, SAX, and Reader parser. Among Nokogiri's many features is the ability to search documents via XPath or CSS3 selectors.
- XML/HTML DOM parser which handles broken HTML
- XML/HTML SAX parser
- XML/HTML Push parser
- XPath 1.0 support for document searching
- CSS3 selector support for document searching
- XML/HTML builder
- XSLT transformer
Nokogiri parses and searches XML/HTML using native libraries (either C or Java, depending on your Ruby), which means it's fast and standards-compliant.
If this doesn't work:
gem install nokogiri
then please start troubleshooting here:
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Instead, tell us when the above instructions don't work for you. This allows us to both help you directly and improve the documentation.
Binary packages are available for some distributions.
- Debian: https://packages.debian.org/sid/ruby-nokogiri
- SuSE: https://download.opensuse.org/repositories/devel:/languages:/ruby:/extensions/
- Fedora: http://s390.koji.fedoraproject.org/koji/packageinfo?packageID=6756
There are open-source tutorials (to which we invite contributions!) here: http://nokogiri.org/tutorials
- The Nokogiri mailing list is active: https://groups.google.com/group/nokogiri-talk
- The Nokogiri bug tracker is here: https://github.com/sparklemotion/nokogiri/issues
- Before filing a bug report, please read our submission guidelines: http://nokogiri.org/tutorials/getting_help.html
- The IRC channel is #nokogiri on freenode.
Security and Vulnerability Reporting
Nokogiri is a large library, but here is example usage for parsing and examining a document:
#! /usr/bin/env ruby require 'nokogiri' require 'open-uri' # Fetch and parse HTML document doc = Nokogiri::HTML(open('http://www.nokogiri.org/tutorials/installing_nokogiri.html')) puts "### Search for nodes by css" doc.css('nav ul.menu li a', 'article h2').each do |link| puts link.content end puts "### Search for nodes by xpath" doc.xpath('//nav//ul//li/a', '//article//h2').each do |link| puts link.content end puts "### Or mix and match." doc.search('nav ul.menu li a', '//article//h2').each do |link| puts link.content end
Ruby 2.1.0 or higher, including any development packages necessary to compile native extensions.
In Nokogiri 1.6.0 and later libxml2 and libxslt are bundled with the gem, but if you want to use the system versions:
First, check out the long list of fixes and changes between releases before deciding to use any version older than is bundled with Nokogiri.
At install time, set the environment variable
NOKOGIRI_USE_SYSTEM_LIBRARIESor else use the
--use-system-librariesargument. (See http://nokogiri.org/tutorials/installing_nokogiri.html#using_your_system_libraries for specifics.)
libxml2 >=2.6.21 with iconv support (libxml2-dev/-devel is also required)
libxslt, built with and supported by the given libxml2 (libxslt-dev/-devel is also required)
Strings are always stored as UTF-8 internally. Methods that return text values will always return UTF-8 encoded strings. Methods that return a string containing markup (like
inner_html) will return a string encoded like the source document.
Some documents declare one encoding, but actually use a different one. In these cases, which encoding should the parser choose?
Data is just a stream of bytes. Humans add meaning to that stream. Any particular set of bytes could be valid characters in multiple encodings, so detecting encoding with 100% accuracy is not possible.
libxml2 does its best, but it can't be right all the time.
If you want Nokogiri to handle the document encoding properly, your best bet is to explicitly set the encoding. Here is an example of explicitly setting the encoding to EUC-JP on the parser:
doc = Nokogiri.XML('<foo><bar /></foo>', nil, 'EUC-JP')
bundle install bundle exec rake