re = /\[img\](.*?)\[\/img\]/i
str = 'http://pt.wikipedia.org/wiki/Erich_von_D%C3%A4niken]Erich Von Daniken[/url][/align] [align=center][img]http://www.ceticismoaberto.com/wp-content/uploads/2012/04/erich_von_daniken_7.jpg[/img]'
# Print the match result
str.match(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