re = /(?=
[ ]{0,8}? \d{1,9}
( .* ) $ # (1)
)
[ \d]{9}
(?= \1 $ )
/xm
str = 'examples of valid strings
123456789
kfasdf 3456789asdf
a 1
and examples of invalid strings
12345 789
1 9
a 678a
'
# 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