re = /(?(DEFINE)
(?<XHTML>
(?&DOCTYPE)
\s*
(?&HTML)
)
# HTML element
(?<HTML>
<html(?&attrs)?>(?&content)<\/html>
)
# Match content
(?<content>
\s*
(?:
((?&tag) | [^<>]+)\s*
)*
)
# General tag
(?<tag>
<((?&tagname))(?&attrs)?\s*(?:
\/>|
>\s*(?&content)\s*
<\/\g'-1'>
)
)
# Attributes
(?<attrs>\s+
# The name
(?&keyword) (
\s*=\s*
(?:
(?&keyword)|
"(?:\\.|.)+?"|
'(?:\\.|.)+?'
)
)?
(?&attrs)?
)
# Match keyword
(?<keyword>[^\s\/>"'=]+)
# Match tag name
(?<tagname>(?!xml)[A-Za-z_][A-Za-z\d_.-]*)
# DOCTYPE expression
(?<DOCTYPE>
<!doctype\s+x?html>
)
)
(?&XHTML)/xi
str = '<!doctype html>
<html style="\'\'inva\'lid css I know">textttt<head></head><body><div class="onfoodstamps"><div class="upper">foo<p>ayyy</p>bar</div>baz</div><br/></head></html>'
# Print the match result
str.scan(re) do |match|
puts match.to_s
end
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html