How Do You Clear The IRB Console?

Question

How do you clear the IRB console screen?

Answer 1

On Mac OS X or Linux you can use Ctrl + L to clear the IRB screen.

Answer 2

Throw this inside %userprofile%\.irbrc and you're good

def cls
  system('cls')
end

From IRB clear screen on windows.

Answer 3

On *nix boxes

`clear`

on Windows

system 'cls' # works
`cls` # does not work

on OSX

system 'clear' # works
`clear` # does not work

Answer 4

On Ubuntu 11.10 system clear will mostly clear the irb window. You get a return => True value printed.

A big mess of ugly text

ruby-1.9.2-p290 :007 > system 'clear'

what ya get:

 => true 
ruby-1.9.2-p290 :007 > 

Answer 5

Command + K in macOS works great.

Answer 6

Just discovered this today: In Pry (an IRB alternative), a line of input that begins with a . will be forwarded to the command shell. Which means in mac & Linux, we can use:

. clear

Update: Unfortunately, it does not seems to work on Windows.

Source: Pryrepl.org

Answer 7

In order to clear the screen just do:

puts "\e[H\e[2J"

P.S. This was tested on Linux.

Answer 8

system 'clear'

Should work for rails 4.0 as well

Answer 9

puts `clear`

Clears the screen and then returns => nil Tested on Mac OSX 10.6 Terminal and iTerm2.

Answer 10

On Linux Mint 17 also you can use Ctrl + Shift + L

or

Ctrl + L to clear the IRB screen.

Answer 11

In windows, using Rails 4,

system('cls')

worked for me

Answer 12

Add the following method to ~/.irbrc:

def clear
  conf.return_format = ""
  system('clear')
end

Cntrl-L or Cntrl-K work in regular console but I'm using tmux and those mess the screen up inside the tmux window.

The conf.return_format = "" takes the nil off the return value.

Answer 13

Windows users simply try,

system 'cls'

OR

system('cls')

Looks like this in the IRB window,

irb(main):333:0> system 'cls'
irb(main):007:0> system('cls')

Did the trick for me in ruby 1.9.3. However the following commands did not work and returned => nil,

system('clear')
system 'clear'
system `cls`       #using the backquotes below ESC Key in windows

Answer 14

I've used this for executable files:

def clear
    system("cls") || system("clear") || puts("\e[H\e[2J")
end

clear

Answer 15

Method: def clear_screen if RUBY_PLATFORM =~ /win32|win64|\.NET|windows|cygwin|mingw32/i system('cls') else system('clear') end end

Or in IRB you can use system('clear')

Answer 16

system 'cls' 

Works for me in Windows, with Ruby 2.2.0 and rails 4.0

Answer 17

Tons of good answers here, but I often remote into a linux box with Mintty from windows. Kudos to the above about using .irbrc, but came up with this:

def cls
  puts "\ec\e[3J"
end

def clear
  puts "\e[H\e[2Js"
end

This gives you the options for both the *nix 'clear' behavior and the Windows 'cls' behavior, which I often find more useful if I really want to nuke the buffer rather than just scrolling it out of view.

P.S. a similar variant also works in .bashrc:

alias cls='echo -e "\ec\e[3J"'

If anyone could find a way to actually map that to a keystroke, I'd love to hear it. I would really like to have something akin to cmd-k on osx that would work in Mintty.

Answer 18

I came here looking for a way to reset the tty with irb, since it wasn't printing newlines or showing what I typed somehow, only some output.

1.9.3-p125 :151 >   system 'reset'

finally did the trick for me!

Answer 19

For windows users:

If you create a bat file name c.bat whose contents are:

@echo off
cls

Then, in IRB, you can say:

system('c')

to clear the console. I just thought I would share because I thought that was pretty cool. Essentially anything in the path is accessible.

Answer 20

->(a,b,c){x=a.method(b);a.send(c,b){send c,b,&x;false};print"\e[2J\e[H \e[D"}[irb_context,:echo?,:define_singleton_method]

This will fully clear your IRB screen, with no extra empty lines and “=> nil” stuff. Tested on Linux/Windows.

This one-liner could be expanded as:

lambda {
  original_echo = irb_context.method(:echo?)
  irb_context.send(:define_singleton_method, :echo?) {
    send :define_singleton_method, :echo?, &original_echo
    false
  }
  print "\e[2J\e[H \e[D"
}.call

This uses lots of tricks.

Firstly, irb will call echo? to check if the result should be printed. I saved the method, then redefined with a method which restores the defination but returns false so irb will not echo the result.

Secondly, I printed some ANSI control chars. \e[2J will clean the screen and \e[H will move the cursor to the upper left position of the screen. \e[D will print a space and then move back the cursor while this is a workaround for something strange on Windows.

Finally this is kind of not practical at all. Just smile ;)

Answer 21

The backtick operator captures the output of the command and returns it

s = `cls`
puts s

would work better, I guess.