re = /[^\s,"]+(?=\s+1200w\b)/m
str = 'srcset="https://cimg.co/w/articles/1/5ca/f022bb06dc.png 150w, https://cimg.co/w/articles/2/5ca/f022bb06dc.png 300w, https://cimg.co/w/articles/3/5ca/f022bb06dc.png 600w, https://cimg.co/w/articles/4/5ca/f022bb06dc.png 1200w"'
# 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