How Do You Clear The IRB Console?

Question

How do you clear the IRB console screen?

Dirndl

Answer 1

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

Dirndl

Ctrl+L also works in gnome-terminal, but something more programmatic is system 'clear' – Bodyguard

With zsh ctrl + L doesn't work, ctrl + K does. (Oh My ZSH to be specific) – Chainplate

@SidneyLiebrand I tested on Oh My ZSH and only Ctrl + L worked – Gradey

@fanaugen On MacOS, cmd+k will clear all within a terminal tap, if you use tmux to split area of the visual area, ctrl+L will do a better work. – Cheddite

I can confirm that this works on Windows 10 as well, both on the Command Prompt and the WSL (running Ubuntu). In WSL, it pushes the prompt to the top (history still remains scrollable) but in Command Prompt, it wipes out all the history too. – Froehlich

Answer 2

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

def cls
  system('cls')
end

From IRB clear screen on windows.

Nailbiting

I should clarify that this applies to Windows only. – Nailbiting

system('clear') will also work on a Mac. It should be noted that this will leave => true at the top of the console. – Redivivus

@anthropomorphic `system('clear') will work on almost every Unix/Unix-like system. – Quechua

@Quechua That's absolutely true, however many people don't know that OS X is a Unix-like system. – Redivivus

@anthropomorphic because it is not. OS X is certified Unix by Open Group. – Quechua

@BenHoffstein - I do not care that this comment is going to get deleted THANK YOU DUDE THANK YOU += >9,000. This took entirely too long to find, relative to my normal stackoverflow expurrrrience. – Thyrse

@BenHoffstein You should put that clarification in the body of your post. And maybe note that for Mac OS its system('clear') – Crompton

Answer 3

On *nix boxes

`clear`

on Windows

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

on OSX

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

Armillia

yeah this doesn't work. Have to do system('clear') or Ctrl + L – Myrticemyrtie

system 'clear' worked for me but I got : command not found => false – Stanfordstang

You can add an alias such as clear you your pryrc file for this. Thanks for sharing – Harshman

Answer 4

Command + K in macOS works great.

Gahan

Answer 5

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 > 

Clap

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 on Mac & Linux, we can use:

. clear

And, on Windows (Command Prompt and Windows Terminal), we can use:

. cls

Source: pry.github.io

Alternative

I just tried this using raw irb under Ruby 2.0.0p481 on Windows and it doesn't work. – Dirndl

Yes. Seems it does not work in windows. But it surely does work in mac & Linux. – Alternative

I like this answer the best. You don't have to modify anything and it's just shelling out. Simple to remember too. Btw, . cls should work on Windows. – Viperish

I wonder which command would work with tmux. I think Ctrl + L is the one as thatway_3 says down below. – Dardani

Answer 7

In order to clear the screen just do:

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

P.S. This was tested on Linux.

Th

This is just the output from `clear`, and is equivalent to puts %x(/usr/bin/clear). – Demy

Answer 8

system 'clear'

Should work for rails 4.0 as well

Arrhenius

Answer 9

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

or

Ctrl + L to clear the IRB screen.

Osteoporosis

Worked for Mac OS X.11.1 in the Terminal app – Quicktempered

@Osteoporosis - nice answer: how did you print the keyboard instructions on Stackoverflow? – Turnkey

Answer 10

puts `clear`

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

Vaccaro

Answer 11

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')

Heptagonal

Answer 12

In windows, using Rails 4,

system('cls')

worked for me

Stephen

Answer 13

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.

Tryptophan

Answer 14

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.

Aurify

Answer 15

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

Bigener

Answer 16

I've used this for executable files:

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

clear

Ean

Answer 17

system 'cls' 

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

Staton

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!

Ruse

simplify it using back ticks: `reset`. – Hendel

@the Tin Man - backticks don't always operate how you think, but reset should work fine – Bodyguard

Backticks always work how I expect but then, I've been using them in various languages for years and years. – Hendel

Indeed, sometimes what resembles a backtick may indeed be some other UTF-8 creature. Occasionally I fix "text" docs with upper and lower quotation marks that are actually != the ANSI/ASCII " character. Like in commercial SRT files, where all hell breaks loose. – Ruse

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.

Duston

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 ;)

Jadotville

Answer 21

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

s = `cls`
puts s

would work better, I guess.

Conduct

This fails: You get this irb(main):004:0> cls => "\f" – Oxytocic

@OrionEdwards @Conduct the first line showed me "\f" which is what you got and then puts s outputs this ♀ I wonder why? – Bigener