re = /([A-Za-z]{4}\d{7})|(\d{9})|(\d{8})/m
str = '12345678
87654321
77777777
CAXA1234564 123456789,
0123456789
AAAA12345678
'
# 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