re = /^(?=.{11,12}$)(?=\S* \S*$)0[ 1-9][ \d]+$/m
str = '01123 456789
01123467 890
0112367 890
012367 890
011 23 456789
011 234567 890
0012 4567890
001 4567890
'
# 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