How to suppress the output of return value in IRB/Rails Console?

问题

An example is if I go into IRB and do the following:

jruby-1.6.7 :026 > puts [1,2,3,4,5]
1
2
3
4
5
=> nil 

Is there anyway to suppress the nil? The problem is if I put in a large data structure, it spams something an other irrelevant return respond. I'm more interested in seeing output from debug statements I run through a block and have to continually scroll up and look for the real data.

回答1:

If you just want to suppress long output once in a while, use ;0, like:

a = [*1..10000];0
# => 0

If you want to suppress it generally, use the ~/.irbrc file. The IRB.conf[:INSPECT_MODE] and IRB.conf[:PROMPT][your_prompt][:RETURN] control what is returned. You can figure out what your_prompt is by checking IRB.conf[:PROMPT_MODE]

Example:

IRB.conf[:PROMPT][:DEFAULT][:RETURN] = "" # suppress return value completely

You'll need to restart irb after changing the value.

Hope that helps.

回答2:

You can also supress the output with the following command as irb --simple-prompt --noecho.

Find the below:

@ubuntu:~$ irb --simple-prompt
>> puts "hi"
hi
=> nil
>> p "hi"
"hi"
=> "hi"
>> exit
@ubuntu:~$ irb --simple-prompt --noecho
>> puts "hi"
hi
>> p "hi"
"hi"
>> 

Hope you will be fine with it.

I am using ruby version as below :

@ubuntu:~$ ruby -v
ruby 1.9.3p194 (2012-04-20 revision 35410) [x86_64-linux]

回答3:

From @Tallboy dead link

To suppress the return value in Rails console, enter
conf.return_format = ""

Default (Print the return value)
conf.return_format = "=> %s\n"

回答4:

i run the following in irb:

irb_context.echo = false

e.g.

$ irb
> "foo"
=> "foo"
> irb_context.echo = false
> "foo"
>

来源：https://stackoverflow.com/questions/10150541/how-to-suppress-the-output-of-return-value-in-irb-rails-console