re = /\d{11}|[1-9]\d{9}|[1-9]\d{4}\s\d{5}|\d{6}\s\d{5}/
str = '1234567890
01234567890
12345 67890
012345 67890
'
# 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