A pure-ruby alternative to ReadLine

RawLine is a 100% Ruby alternative to the ReadLine library, providing some of its most popular features such as:

  • Basic line editing operations
  • Word completion
  • History Management
  • Custom key/key sequences bindings


The simplest method to install RawLine is to install the gem:

gem install rawline


Editor initialization:

require 'rawline'
editor = RawLine::Editor.new

Key binding:

editor.bind(:ctrl_z) { editor.undo }
editor.bind(:up_arrow) { editor.history_back }
editor.bind(:ctrl_x) { puts "Exiting..."; exit }

Setup word completion

editor.completion_proc = lambda do |word|
	if word
		['select', 'update', 'delete', 'debug', 'destroy'].find_all  { |e| e.match(/^#{Regexp.escape(word)}/) }

editor.completion_append_string = " "

Read input:

editor.read("=> ", true)

Replacing Readline

Simply include the RawLine (or Rawline) module:

include Rawline

…and you’ll get:

readline(prompt, add_history) # RawLine::Editor#read(prompt, add_history)
HISTORY # RawLine::Editor#history
FILENAME_COMPLETION_PROC # Rawline::Editor#filename_completion_proc
# ...

but also:

Rawline.editor # RawLine::Editor

…which opens a world of endless possibilities! ;-)

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