Nokogiri is a HTML, XML, SAX and Reader parser.
# To parse the contents of a url or file:
nokogiri <url|path/to/file>
# To parse as a specific type:
nokogiri <url|path/to/file> --type <xml|html>
# To load a specific initialisation file before parsing:
nokogiri <url|path/to/file> -C <path/to/config_file>
# To parse using a specific encoding:
nokogiri <url|path/to/file> --encoding <encoding>
# To validate using a RELAX NG file:
nokogiri <url|path/to/file> --rng <url|path/to/file>