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Callback for puts and warn Ruby

I am trying to have a callback for all iterations of puts (puts, p) and warn.

For example:

puts "test" -> def callback() -> "test"

How would I be able to achieve this?

Solution

  • You can do this, but be really sure you want to, because it will apply to the entire Ruby runtime whenever you do. If you are working on a project with other people, be sure to get their buy-in.

    To do this, you alias the original method to an additional method name. Then you redefine the method to do your own processing, which I presume ends with calling the original method. For example, for puts:

    #!/usr/bin/env ruby

module Kernel
    alias original_puts puts
    def puts(object)
        # Do my own processing here, e.g.
        original_puts "This is coming from my overrided puts:"
        original_puts(object)
    end
end

puts 'hi'

=begin

Outputs:

This is coming from my overrided puts:
hi

=end