rosettea / readline

Readline bindings for Go

Readline Bindings

This is a set of bindings to the GNU Readline Library.

The existing readline bindings for Go are more limited than this library, if you can believe it.

Note that the return type of String() has changed.

It was

func String(prompt string) string

and it's now

func String(prompt string) (string, error)

Installing the library

To install the library in order to use it, type:

go get github.com/bobappleyard/readline

You may need to be root.

For Mac OS X users, you may see errors like rl_catch_sigwinch undeclared. If so, you need to install GNU Readline via Homebrew:

brew install readline

On Mac OS X, if you encounter errors like these:

> go get github.com/bobappleyard/readline
# github.com/bobappleyard/readline
readline.go:38:19: error: stdio.h: No such file or directory
readline.go:39:20: error: stdlib.h: No such file or directory
In file included from /usr/local/opt/readline/include/readline/keymaps.h:35,
    	         from /usr/local/opt/readline/include/readline/readline.h:37,
            	 from readline.go:40:
/usr/local/opt/readline/include/readline/chardefs.h:25:19: error: ctype.h: No such file or directory
/usr/local/opt/readline/include/readline/chardefs.h:38:22: error: string.h: No such file or directory
In file included from readline.go:41:
/usr/local/opt/readline/include/readline/history.h:29:58: error: time.h: No such file or directory

You need to install "Command Line Tools" which can be done in XCode > Preferences > Downloads.

To install the library in order to hack on it, type

git clone git://github.com/bobappleyard/readline.git

Using the library

import "github.com/bobappleyard/readline"

These bindings provide access to three basic features of Readline:

• Getting text from a prompt (via the String() and Reader() functions).
• Managing the prompt's history (via the AddHistory(), GetHistory(), ClearHistory() and HistorySize() functions).
• Controlling tab completion (via the Completer variable).

An example of the library's use:

package main

import (
	"io"
	"fmt"
	"github.com/bobappleyard/readline"
)

func main() {
	for {
		l, err := readline.String("> ")
		if err == io.EOF {
			break
		}
		if err != nil {
			fmt.Println("error: ", err)
			break
		}
		fmt.Println(l)
		readline.AddHistory(l)
	}
}