/usr/lib/ruby/vendor_ruby/rails/generators/erb/mailer/templates/view.text.erb is in ruby-railties 2:4.2.6-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | <%= class_name %>#<%= @action %>
<%%= @greeting %>, find me in <%= @path %>
|