irb history not working

Question

in ~/.irbrc i have these lines:

require 'irb/ext/save-history'
#History configuration
IRB.conf[:SAVE_HISTORY] = 100
IRB.conf[:HISTORY_FILE] = "#{ENV['HOME']}/.irb-save-history"

and yet when i run irb and hit the up arrow nothing happens. also the irb history file specified is not getting created and nothing is logged to it.

What platform are you using? I'm pretty sure the default OS X install doesn't have readline support built in due to licensing issues. — Dave Bacher, Jan 14 '10 at 17:53
What you have there appears to work for me on doze, except that I have to hit two up arrows for some reason. — rogerdpack, Apr 27 '10 at 18:54
This solution worked for me: http://stackoverflow.com/questions/1752461/history-not-saving — Noah Sussman, Jan 20 '11 at 13:21
See also https://stackoverflow.com/questions/37847822/irb-history-not-working-with-ruby-2-3-0?noredirect=1&lq=1 which discusses how ruby must be complied with `readline` — Jared Beck, Jan 31 '18 at 17:04

score 20 · Answer 1 · answered Jan 14 '10 at 17:56

20

irb history works in Debian Linux out of the box. There's no etc/irbrc, nor do I have a ~/.irbrc. So, hmmmm.

This person put a bit more in his irbrc than you did. Do you suppose the ARGV.concat could be the missing piece?

require 'irb/completion'
require 'irb/ext/save-history'
ARGV.concat [ "--readline", "--prompt-mode", "simple" ]
IRB.conf[:SAVE_HISTORY] = 100
IRB.conf[:HISTORY_FILE] = "#{ENV['HOME']}/.irb-save-history"

answered Jan 14 '10 at 17:56

Wayne Conrad

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RVM automatically adds an irbrc that does it. Not present on Ubuntu out of box without RVM. – Ciro Santilli Путлер Капут 六四事 Oct 14 '14 at 16:51

score 11 · Accepted Answer · answered Jan 14 '10 at 17:50

I don't have an answer for you why the above doesn't work, but I did find a file, /etc/irbrc on my system (OS X - Snow Leopard, Ruby 1.8.7) that does provide a working, persistent history for me. So two pieces of advice: i) check your /etc/irbrc (or equivalent) to make sure that there isn't anything in there that might interfere with your settings, and ii) try out the settings below to see if you can get history working that way.

# Some default enhancements/settings for IRB, based on
# http://wiki.rubygarden.org/Ruby/page/show/Irb/TipsAndTricks

unless defined? ETC_IRBRC_LOADED

  # Require RubyGems by default.
  require 'rubygems'

  # Activate auto-completion.
  require 'irb/completion'

  # Use the simple prompt if possible.
  IRB.conf[:PROMPT_MODE] = :SIMPLE if IRB.conf[:PROMPT_MODE] == :DEFAULT

  # Setup permanent history.
  HISTFILE = "~/.irb_history"
  MAXHISTSIZE = 100
  begin
    histfile = File::expand_path(HISTFILE)
    if File::exists?(histfile)
      lines = IO::readlines(histfile).collect { |line| line.chomp }
      puts "Read #{lines.nitems} saved history commands from '#{histfile}'." if $VERBOSE
      Readline::HISTORY.push(*lines)
    else
      puts "History file '#{histfile}' was empty or non-existant." if $VERBOSE
    end
    Kernel::at_exit do
      lines = Readline::HISTORY.to_a.reverse.uniq.reverse
      lines = lines[-MAXHISTSIZE, MAXHISTSIZE] if lines.nitems > MAXHISTSIZE
      puts "Saving #{lines.length} history lines to '#{histfile}'." if $VERBOSE
      File::open(histfile, File::WRONLY|File::CREAT|File::TRUNC) { |io| io.puts lines.join("\n") }
    end
  rescue => e
    puts "Error when configuring permanent history: #{e}" if $VERBOSE
  end

  ETC_IRBRC_LOADED=true
end

despite that this seems kind of like faking it, this works for me. I know irb must have this feature built in somewhere. Oh well, i have a history now. thanks! — quinn, Jan 14 '10 at 19:59
This was a great help to me. I would however note that I changed: `lines.nitems` into `lines.count` because lines.nitems don't work for me. — Franco Rondini, Jun 08 '12 at 08:38
`/etc/irbrc` on OS X is now out of date. See [this question](http://stackoverflow.com/questions/37617519/is-etc-irbrc-installed-by-os-x-does-irb-read-it). — Franklin Yu, Nov 19 '16 at 20:15

score 1 · Answer 3 · answered Feb 06 '10 at 13:35

1

This is a known bug with a patch available. Easiest solution is to overwrite save-history.rb:

/usr/lib/ruby/1.8/irb/ext/save-history.rb

with a fixed version:

http://pastie.org/513500

or to do it in one go:

wget -O /usr/lib/ruby/1.8/irb/ext/save-history.rb http://pastie.org/pastes/513500/download

answered Feb 06 '10 at 13:35

Mike McKay

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is there a bug report on this anywhere? a linK? Thanks. – rogerdpack Apr 27 '10 at 18:52

score 0 · Answer 4 · answered Aug 05 '16 at 10:58

0

This may also happen if you have extra irb config file, e.g. ~/.irbrc. If this is the case, copy the content from liwp's answer to the extra config and it should work.

answered Aug 05 '16 at 10:58

medik

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score 0 · Answer 5 · answered Dec 11 '20 at 14:17

0

I had the same problem on ubuntu 20.04 and fixed it by running:

gem install irb

answered Dec 11 '20 at 14:17

Rob Geraghty

96
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score 0 · Answer 6 · answered Jan 03 '12 at 17:44

0

Check to make sure you built ruby with libreadline as irb history seems to not work without it.

answered Jan 03 '12 at 17:44

jwood

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irb history not working

6 Answers6

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