How to suppress Rails console/irb outputs

irb --simple-prompt --noecho

• --simple-prompt - Uses a simple prompt - just >>
• --noecho - Suppresses the result of operations

You can append ; nil to your statements.

Example:

users = User.all; nil

irb prints the return value of the last executed statement; thus in this case it'll print only nil since nil is the last executed valid statement.

Here, add this to your ~/.irbrc:

require 'ctx'
require 'awesome_print'

module IRB
  class Irb    
    ctx :ap do
      def output_value()
        ap(@context.last_value)
      end
    end
    ctx :puts do
      def output_value()
        puts(@context.last_value)
      end
    end
    ctx :p do
      def output_value()
        p(@context.last_value)
      end
    end
    ctx :quiet do
      def output_value()
      end
    end
  end
end

def irb_mode(mode)
  ctx(mode) { irb }
end

(Note: You must install the ctx gem first, though awesome_print is optional, of course.)

Now when you are on any console that uses irb, you can do the following:

Normal mode:

irb(main):001:0> { this:'is a complex object', that:[ { will:'probably'}, { be:'good to read' } ], in:{ some:{ formatted:'way'} } }

=> {:this=>"is a complex object", :that=>[{:will=>"probably"}, {:be=>"good to read"}], :in=>{:some=>{:formatted=>"way"}}}

...yep, just what you expect.

awesome_print mode:

irb(main):002:0> irb_mode(:ap)
irb#1(main):001:0> { this:'is a complex object', that:[ { will:'probably'}, { be:'good to read' } ], in:{ some:{ formatted:'way'} } }

=> {
    :this => "is a complex object",
    :that => [
        [0] {
            :will => "probably"
        },
        [1] {
            :be => "good to read"
        }
    ],
      :in => {
        :some => {
            :formatted => "way"
        }
    }
}

...wow, now everything is printing out awesomely! :)

Quiet mode:

irb#1(main):002:0> irb_mode(:quiet)
irb#1(main):001:0> { this:'is a complex object', that:[ { will:'probably'}, { be:'good to read' } ], in:{ some:{ formatted:'way'} } }
irb#1(main):002:0>

... whoah, no output at all? Nice.

Anyways, you can add whatever mode you like, and when you're finished with that mode, just exit out or it, and you'll be back in the previous mode.

Hope that was helpful! :)

In search of a solution how to silence the irb/console output, I also found an answer at austinruby.com:

silence irb:

conf.return_format = ""

default output:

conf.return_format = "=> %s\n"

limit to eg 512 chars:

conf.return_format = "=> limited output\n %.512s\n"