diff --git a/example/demo.gif b/example/demo.gif new file mode 100644 index 0000000..64fbb6c Binary files /dev/null and b/example/demo.gif differ diff --git a/example/main.go b/example/main.go new file mode 100644 index 0000000..995456b --- /dev/null +++ b/example/main.go @@ -0,0 +1,42 @@ +package main + +import ( + "io" + "log" + "strconv" + "time" + + "github.com/chzyer/readline" +) + +func main() { + t, err := readline.NewTerminal() + if err != nil { + panic(err) + } + defer t.Close() + + l := t.NewReadline("> ") + log.SetOutput(l.Stderr()) + for { + line, err := l.Readline() + if err != nil { + break + } + switch line { + case "help": + io.WriteString(l.Stderr(), "sayhello: start to display oneline log per second\nbye: quit\n") + case "sayhello": + go func() { + for _ = range time.Tick(time.Second) { + log.Println("hello") + } + }() + case "bye": + goto exit + default: + log.Println("you said:", strconv.Quote(line)) + } + } +exit: +} diff --git a/readline.go b/readline.go new file mode 100644 index 0000000..342643e --- /dev/null +++ b/readline.go @@ -0,0 +1,103 @@ +package readline + +import ( + "io" + "os" +) + +type Readline struct { + r *os.File + t *Terminal + buf *RuneBuffer + outchan chan []rune +} + +const ( + CharLineStart = 0x1 + CharLineEnd = 0x5 + CharPrev = 0x2 + CharNext = 0x6 + CharEscape = 0x7f + CharEnter = 0xd +) + +type wrapWriter struct { + r *Readline + target io.Writer +} + +func (w *wrapWriter) Write(b []byte) (int, error) { + buf := w.r.buf + buf.Clean() + n, err := w.target.Write(b) + w.r.buf.RefreshSet(0, 0) + return n, err +} + +func newReadline(r *os.File, t *Terminal, prompt string) *Readline { + rl := &Readline{ + r: r, + t: t, + buf: NewRuneBuffer(t, prompt), + outchan: make(chan []rune), + } + go rl.ioloop() + return rl +} + +func (l *Readline) ioloop() { + for { + r := l.t.ReadRune() + switch r { + case MetaNext: + l.buf.MoveToNextWord() + case MetaPrev: + l.buf.MoveToPrevWord() + case MetaDelete: + l.buf.DeleteWord() + case CharLineStart: + l.buf.MoveToLineStart() + case CharLineEnd: + l.buf.MoveToLineEnd() + case KeyDelete: + l.buf.Delete() + case CharEscape: + l.buf.BackEscape() + case CharEnter: + l.buf.WriteRune('\n') + data := l.buf.Reset() + l.outchan <- data[:len(data)-1] + case CharPrev: + l.buf.MovePrev() + case CharNext: + l.buf.MoveNext() + case KeyInterrupt: + l.buf.WriteString("^C\n") + l.outchan <- nil + break + default: + l.buf.WriteRune(r) + } + } +} + +func (l *Readline) Stderr() io.Writer { + return &wrapWriter{target: os.Stderr, r: l} +} + +func (l *Readline) Readline() (string, error) { + r, err := l.ReadlineSlice() + if err != nil { + return "", err + } + return string(r), nil +} + +func (l *Readline) ReadlineSlice() ([]byte, error) { + l.buf.Refresh(0, 0) + r := <-l.outchan + if r == nil { + return nil, io.EOF + } + return []byte(string(r)), nil +} diff --git a/runebuf.go b/runebuf.go new file mode 100644 index 0000000..33348d4 --- /dev/null +++ b/runebuf.go @@ -0,0 +1,189 @@ +package readline + +import ( + "bytes" + "io" +) + +type RuneBuffer struct { + buf []rune + idx int + prompt []byte + w io.Writer + lastWritten int + printPrompt bool +} + +func NewRuneBuffer(w io.Writer, prompt string) *RuneBuffer { + rb := &RuneBuffer{ + prompt: []byte(prompt), + w: w, + printPrompt: true, + } + return rb +} + +func (r *RuneBuffer) Runes() []rune { + return r.buf +} + +func (r *RuneBuffer) Pos() int { + return r.idx +} + +func (r *RuneBuffer) Len() int { + return len(r.buf) +} + +func (r *RuneBuffer) MoveToLineStart() { + if r.idx == 0 { + return + } + r.Refresh(-1, r.SetIdx(0)) +} + +func (r *RuneBuffer) MovePrev() { + if r.idx == 0 { + return + } + r.idx-- + r.Refresh(0, -1) +} + +func (rb *RuneBuffer) WriteString(s string) { + rb.WriteRunes([]rune(s)) +} + +func (rb *RuneBuffer) WriteRune(r rune) { + rb.WriteRunes([]rune{r}) +} + +func (rb *RuneBuffer) WriteRunes(r []rune) { + tail := append(r, rb.buf[rb.idx:]...) + rb.buf = append(rb.buf[:rb.idx], tail...) + rb.idx++ + rb.Refresh(1, 1) +} + +func (r *RuneBuffer) MoveNext() { + if r.idx == len(r.buf) { + return + } + r.idx++ + r.Refresh(0, 1) +} + +func (r *RuneBuffer) Delete() { + if r.idx == len(r.buf) { + return + } + r.buf = append(r.buf[:r.idx], r.buf[r.idx+1:]...) + r.Refresh(-1, 0) +} + +func (r *RuneBuffer) DeleteWord() { + if r.idx == len(r.buf) { + return + } + for i := r.idx + 1; i < len(r.buf); i++ { + if r.buf[i] != ' ' && r.buf[i-1] == ' ' { + r.buf = append(r.buf[:r.idx], r.buf[i-1:]...) + r.Refresh(r.idx-i+1, 0) + return + } + } + length := len(r.buf) + r.buf = r.buf[:r.idx] + r.Refresh(length-r.idx, 0) +} + +func (r *RuneBuffer) MoveToPrevWord() { + if r.idx == 0 { + return + } + for i := r.idx - 1; i > 0; i-- { + if r.buf[i] != ' ' && r.buf[i-1] == ' ' { + r.Refresh(0, r.SetIdx(i)) + return + } + } + r.Refresh(0, r.SetIdx(0)) +} + +func (r *RuneBuffer) SetIdx(idx int) (change int) { + i := r.idx + r.idx = idx + return r.idx - i +} + +func (r *RuneBuffer) MoveToNextWord() { + for i := r.idx + 1; i < len(r.buf); i++ { + if r.buf[i] != ' ' && r.buf[i-1] == ' ' { + r.Refresh(0, r.SetIdx(i)) + return + } + } + r.Refresh(0, r.SetIdx(len(r.buf))) +} + +func (r *RuneBuffer) BackEscape() { + if r.idx == 0 { + return + } + r.idx-- + r.buf = append(r.buf[:r.idx], r.buf[r.idx+1:]...) + r.Refresh(-1, -1) +} + +func (r *RuneBuffer) MoveToLineEnd() { + if r.idx == len(r.buf) { + return + } + r.Refresh(0, r.SetIdx(len(r.buf))) +} + +func (r *RuneBuffer) Refresh(chlen, chidx int) { + s := r.Output(len(r.buf)-chlen, r.idx-chidx) + r.w.Write(s) +} + +func (r *RuneBuffer) RefreshSet(originLength, originIdx int) { + r.w.Write(r.Output(originLength, originIdx)) +} + +func (r *RuneBuffer) Output(originLength, originIdx int) []byte { + buf := bytes.NewBuffer(nil) + if r.printPrompt { + r.printPrompt = false + buf.Write(r.prompt) + } + + buf.Write(bytes.Repeat([]byte{'\b'}, originIdx)) + buf.Write([]byte(string(r.buf))) + if originLength > len(r.buf) { + buf.Write(bytes.Repeat([]byte{' '}, originLength-len(r.buf))) + buf.Write(bytes.Repeat([]byte{'\b'}, originLength-len(r.buf))) + } + buf.Write(bytes.Repeat([]byte{'\b'}, len(r.buf)-r.idx)) + return buf.Bytes() +} + +func (r *RuneBuffer) Clean() { + moveToFirst := r.idx + moveToFirst += len(r.prompt) + r.w.Write(bytes.Repeat([]byte{'\b'}, moveToFirst)) + length := len(r.buf) + len(r.prompt) + + r.w.Write(bytes.Repeat([]byte{' '}, length)) + r.w.Write(bytes.Repeat([]byte{'\b'}, length)) + r.printPrompt = true +} + +func (r *RuneBuffer) Reset() []rune { + ret := r.buf + r.buf = r.buf[:0] + r.idx = 0 + r.printPrompt = true + r.Refresh(-len(ret), r.SetIdx(0)) + return ret +} diff --git a/terminal.go b/terminal.go new file mode 100644 index 0000000..de78782 --- /dev/null +++ b/terminal.go @@ -0,0 +1,108 @@ +package readline + +import ( + "bufio" + "fmt" + "os" + "sync/atomic" + "syscall" + + "golang.org/x/crypto/ssh/terminal" +) + +const ( + MetaPrev = -iota - 1 + MetaNext + MetaDelete +) + +const ( + KeyPrevChar = 0x2 + KeyInterrupt = 0x3 + KeyNextChar = 0x6 + KeyDelete = 0x4 + KeyEnter = 0xd + KeyEsc = 0x1b +) + +type Terminal struct { + state *terminal.State + outchan chan rune + closed int64 +} + +func NewTerminal() (*Terminal, error) { + state, err := MakeRaw(syscall.Stdin) + if err != nil { + return nil, err + } + t := &Terminal{ + state: state, + outchan: make(chan rune), + } + + go t.ioloop() + return t, nil +} + +func (t *Terminal) Write(b []byte) (int, error) { + return os.Stdout.Write(b) +} + +func (t *Terminal) Print(s string) { + fmt.Fprintf(os.Stdout, "%s", s) +} + +func (t *Terminal) PrintRune(r rune) { + fmt.Fprintf(os.Stdout, "%c", r) +} + +func (t *Terminal) NewReadline(prompt string) *Readline { + return newReadline(os.Stdin, t, prompt) +} + +func (t *Terminal) ReadRune() rune { + return <-t.outchan +} + +func (t *Terminal) ioloop() { + buf := bufio.NewReader(os.Stdin) + prefix := false + for { + r, _, err := buf.ReadRune() + if err != nil { + break + } + + if prefix { + prefix = false + r = prefixKey(r) + } + + if IsPrintable(r) || r < 0 { + t.outchan <- r + continue + } + switch r { + case KeyInterrupt: + t.outchan <- r + goto exit + case KeyEsc: + prefix = true + case KeyEnter, KeyPrevChar, KeyNextChar, KeyDelete: + fallthrough + case CharLineEnd, CharLineStart: + t.outchan <- r + default: + println("np:", r) + } + } +exit: +} + +func (t *Terminal) Close() error { + if atomic.SwapInt64(&t.closed, 1) != 0 { + return nil + } + return Restore(syscall.Stdin, t.state) +} diff --git a/utils.go b/utils.go new file mode 100644 index 0000000..cfbc5b0 --- /dev/null +++ b/utils.go @@ -0,0 +1,44 @@ +package readline + +import ( + "fmt" + "os" + + "golang.org/x/crypto/ssh/terminal" +) + +// IsTerminal returns true if the given file descriptor is a terminal. +func IsTerminal(fd int) bool { + return terminal.IsTerminal(fd) +} + +func MakeRaw(fd int) (*terminal.State, error) { + return terminal.MakeRaw(fd) +} + +func Restore(fd int, state *terminal.State) error { + return terminal.Restore(fd, state) +} + +func IsPrintable(key rune) bool { + isInSurrogateArea := key >= 0xd800 && key <= 0xdbff + return key >= 32 && !isInSurrogateArea +} + +func prefixKey(r rune) rune { + switch r { + case 'b': + r = MetaPrev + case 'f': + r = MetaNext + case 'd': + r = MetaDelete + } + return r +} + +func Debug(o ...interface{}) { + f, _ := os.OpenFile("debug.tmp", os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666) + fmt.Fprintln(f, o...) + f.Close() +}