Liner

Liner is a command line editor with history. It was inspired by linenoise; everything Unix-like is a VT100 (or is trying very hard to be). If your terminal is not pretending to be a VT100, change it. Liner also support Windows.

Liner is intended for use by cross-platform applications. Therefore, the decision was made to write it in pure Go, avoiding cgo, for ease of cross compilation. Furthermore, features only supported on some platforms have been intentionally omitted. For example, Ctrl-Z is "suspend" on Unix, but "EOF" on Windows. In the interest of making an application behave the same way on every supported platform, Ctrl-Z is ignored by Liner.

Liner is released under the X11 license (which is similar to the new BSD license).

Line Editing

The following line editing commands are supported on platforms and terminals that Liner supports:

Note that "Previous" and "Next match from history" will retain the part of the line that the user has already typed, similar to zsh's "up-line-or-beginning-search" (which is the default on some systems) or bash's "history-search-backward" (which is my preferred behaviour, but does not appear to be the default Up keybinding on any system).

Getting started

package main

import (
	"log"
	"os"
	"path/filepath"
	"strings"

	"github.com/peterh/liner"
)

var (
	history_fn = filepath.Join(os.TempDir(), ".liner_example_history")
	names      = []string{"john", "james", "mary", "nancy"}
)

func main() {
	line := liner.NewLiner()
	defer line.Close()

	line.SetCtrlCAborts(true)

	line.SetCompleter(func(line string) (c []string) {
		for _, n := range names {
			if strings.HasPrefix(n, strings.ToLower(line)) {
				c = append(c, n)
			}
		}
		return
	})

	if f, err := os.Open(history_fn); err == nil {
		line.ReadHistory(f)
		f.Close()
	}

	if name, err := line.Prompt("What is your name? "); err == nil {
		log.Print("Got: ", name)
		line.AppendHistory(name)
	} else if err == liner.ErrPromptAborted {
		log.Print("Aborted")
	} else {
		log.Print("Error reading line: ", err)
	}

	if f, err := os.Create(history_fn); err != nil {
		log.Print("Error writing history file: ", err)
	} else {
		line.WriteHistory(f)
		f.Close()
	}
}

For documentation, see http://godoc.org/github.com/peterh/liner