re = /^(?:(?!.*LT circa).+\n)*(?:(?!LT circa).)*LT circa\s+(\d\d\.\d\d.\d{4})(?!(?:.+\n)*.*LT circa)/
str = 'Metall-Notierung 464,95 EUR 100 KG
* LT circa 21.04.2020 2 x 500 M Einwegtrommel 400x 150x 404mm
* LT circa 17.05.2020 2 x 500 M Einwegtrommel 400x 150x 404mm
Zolltarifnummer 80464995'
# 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