re = /(?<=asad=).*?(?=(?:&|\n))/
str = 'https://teststore.com/products/mens-sandals-black?asad=253485_e1c6ae3ad&ol_color=13968
https://teststore.com/products/womens-sandals-tan-?asad=252485_c1c63c01d&variant=2770725251
https://teststore.com/products/mens-shoes-blue?asad=254325_c1c63c01d
https://teststore.com/collections/men/products/mens-sneakers?variant=310637539&asad=204207_e1c1756d5
'
# 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