re = /^{{\w+}}(?:_{{\w+}})*$/m
str = '{{word1}}_{{word2}}_{{word3}}
_{{word1}}_{{word2}}_{{word3}}.
{{word1}}_word{{word2}}_{{word3}}
{{word1}}_{{word2}}_{{word3}}word4
{{word1}}_{{word2}}_{{word3}}_
_{{word1}}_{{word2}}_{{word3}}_
{{word1}}_{{word2))_{{word3}}
+{{word1}}-{{word2}}_{{word3}
word{{word}}_{{word2}}_'
# 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