Rails console issues using JRuby: no prompt character, no tab completion, broken arrow keys, etc

问题

I'm having various issues with my Rails console under JRuby, including

No prompt character
Tab completion not working (literal tab gets inserted)
Up/down arrows not browsing history (^[[A or ^[[B gets inserted, respectively)
Left/right arrows not moving cursor (^[[D or ^[[C gets inserted, respectively)
Home/End keys not moving cursor to beginning/end of line (instead 1~ or 4~ inserted, respectively); Ctrl+a / Ctrl+e work though
Ctrl+c killing console instead of killing the line I'm entering
Ctrl+d not having any effect until I hit Enter (which then executes anything I entered between Ctrl+d and Enter in my Unix shell).

I installed my JRuby interpreter from rvm like so:

rvm install jruby-1.6.8 --1.9

My Rails project is managed using Bundler (not rvm gemsets), so I run my Rails console using bundle exec rails c. Interestingly, raw irb as well as bundle exec irb don't have most of the above issues, except the Home/End keys and Ctrl+c needs an Enter before I get a fresh prompt line.

I can replicate the issue with a barebones Rails Gemfile:

source 'https://rubygems.org'
gem 'rails', '3.2.6'
gem 'sqlite3'

My shell is zsh, on Ubuntu 12.04 64-bit. $JAVA_HOME is /usr/lib/jvm/java-7-openjdk-amd64, but it might have still been java-6 when I installed this interpreter, if that matters.

Update: Some fixes

The missing prompt character is apparently caused by the IRB.conf[:PROMPT_MODE] getting set to :NULL by the Rails console. For regular irb, mine gets set to :RVM (apparently rvm does this in ~/.rvm/scripts/irb.rb; I ruled out rvm causing this issue by commenting out the script). Providing a :PROMPT_MODE value in ~/.irbrc fixes this. I thought maybe a similar issue was causing the Ctrl+c / Ctrl+d problems by changing :IGNORE_SIGINT and :IGNORE_EOF, but they are both set to their default values.

Tab completion and arrow keys get fixed by setting :USE_READLINE to true.

Here's my current ~/.irbrc that seems to fix said issues:

require 'irb/completion'

IRB.conf[:PROMPT_MODE]  = :SIMPLE
IRB.conf[:USE_READLINE] = true
IRB.conf[:AUTO_INDENT]  = true

回答1:

Running the console with the following fixed these sorts of problems for me:

jruby -Xlaunch.inproc=true -S rails c

If you don't like running that command every time, you can set an environment variable:

set JRUBY_OPTS=-Xlaunch.inproc=true

export JRUBY_OPTS=-Xlaunch.inproc=true

then

rails c

回答2:

I had this issue with Windows and the fix was to increase the "Number of Buffers" in the Command prompt settings. Command Prompt -> Properties -> Options -> Number of Buffers Default is 4, I changed to 8 and all worked well (I think 5 would work though)

来源：https://stackoverflow.com/questions/13649437/rails-console-issues-using-jruby-no-prompt-character-no-tab-completion-broken

标签

ruby-on-rails

jruby

rails-console