readline

Readline is A Pure Go Implementation of a libreadline-style Library.
The goal is to be a powerful alternater for GNU-Readline.

WHY: Readline will support most of features which GNU Readline is supported, and provide a pure go environment and a MIT license.

It can also provides shell-like interactives by using flagly (demo: flagly-shell)

Demo

Also works fine in windows

• example/readline-demo The source code about the demo above

• example/readline-im Example for how to write a IM program.

• example/readline-multiline Example for how to parse command which can submit by multiple time.

• example/readline-pass-strength A example about checking password strength, written by @sahib

Todo

• Vi Mode is not completely finish
• More funny examples
• Support dumb/eterm-color terminal in emacs

Features

• Support emacs/vi mode, almost all basic features that GNU-Readline is supported
• zsh-style backward/forward history search
• zsh-style completion
• Readline auto refresh when others write to Stdout while editing (it needs specify the Stdout/Stderr provided by *readline.Instance to others).
• Support colourful prompt in all platforms.

Usage

• Import package

go get gopkg.in/readline.v1

or

go get github.com/chzyer/readline

• Simplest example

import "gopkg.in/readline.v1"

rl, err := readline.New("> ")
if err != nil {
	panic(err)
}
defer rl.Close()

for {
	line, err := rl.Readline()
	if err != nil { // io.EOF, readline.ErrInterrupt
		break
	}
	println(line)
}

• Example with durable history

rl, err := readline.NewEx(&readline.Config{
	Prompt: "> ",
	HistoryFile: "/tmp/readline.tmp",
})
if err != nil {
	panic(err)
}
defer rl.Close()

for {
	line, err := rl.Readline()
	if err != nil { // io.EOF, readline.ErrInterrupt
		break
	}
	println(line)
}

• Example with auto completion

import (
	"gopkg.in/readline.v1"
)

var completer = readline.NewPrefixCompleter(
	readline.PcItem("say",
		readline.PcItem("hello"),
		readline.PcItem("bye"),
	),
	readline.PcItem("help"),
)

rl, err := readline.NewEx(&readline.Config{
	Prompt:       "> ",
	AutoComplete: completer,
})
if err != nil {
	panic(err)
}
defer rl.Close()

for {
	line, err := rl.Readline()
	if err != nil { // io.EOF, readline.ErrInterrupt
		break
	}
	println(line)
}

Shortcut

Meta+B means press Esc and n separately.
Users can change that in terminal simulator(i.e. iTerm2) to Alt+B
Notice: Meta+B is equals with Alt+B in windows.

• Shortcut in normal mode

• Shortcut in Search Mode (Ctrl+S or Ctrl+r to enter this mode)

• Shortcut in Complete Select Mode (double Tab to enter this mode)

Tested with

Notice:

• Ctrl+A is not working in screen because it used as a control command by default

If you test it otherwhere, whether it works fine or not, please let me know!

Who is using Readline

• cockroachdb/cockroach
• youtube/doorman
• bom-d-van/harp
• abiosoft/ishell
• robertkrimen/otto
• Netflix/hal-9001
• docker/go-p9p

Feedback

If you have any questions, please submit a github issue and any pull requests is welcomed :)

• https://twitter.com/chzyer
• http://weibo.com/2145262190

Backers

Love Readline? Help me keep it alive by donating funds to cover project expenses!
[Become a backer]

Sponsors

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