Remove trailing spaces from each line in a string in ruby -

can me, how remove trailing white spaces each line in string in ruby.... example:

str = "hello everyone. \nhope guys doing  \nstrange can't remove spaces" 

i tried rstrip not working me.... may have try gsub.... want answer in below wayy.

"hello everyone.\nhope guys doing good\nstrange can't remove spaces" 

str.split("\n").map(&:rstrip).join("\n") 

its doable regex prefer way.