How to suppress Rails console/irb outputs
-
10-10-2019 - |
Question
I'm stuck with a pretty weird problem.
I was testing some db entries in our production server in Rails Console where almost all the commands were resulting a huge number of o/p lines, due to which the ssh channel was getting hanged :(
Is there a way to suppress the console/irb screenfuls?
Thanks
Solution
You can append ; nil to all your your commands/statements.
Example:
users = User.all; nil
Actually irb prints the (return) value of the last executed statement. Thus in this case it'll print only nil as nil is the last executed valid statement :)
OTHER TIPS
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"
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! :)
Supress Output, In General
Also, depending on your needs, have a look at using quietly
or silence_stream
for suppressing output in general, not just in the irb/console:
silence_stream(STDOUT) do
users = User.all
end
NOTE: quietly
will be deprecated in Ruby 2.2.0 and will eventually be removed. (Thanks BenMorganIO!)
More information can be found here.
$ irb --simple-prompt --noecho
running the following within irb works for me:
irb_context.echo = false