package main import ( "io" "log" "strconv" "strings" "time" "github.com/chzyer/readline" ) func usage(w io.Writer) { io.WriteString(w, ` sayhello: start to display oneline log per second bye: quit `[1:]) } var completer = readline.NewPrefixCompleter( readline.PcItem("say", readline.PcItem("hello"), readline.PcItem("bye"), ), readline.PcItem("bye"), readline.PcItem("help"), readline.PcItem("go", readline.PcItem("build"), readline.PcItem("install"), readline.PcItem("test"), ), ) func main() { l, err := readline.NewEx(&readline.Config{ Prompt: "\033[31m»\033[0m ", HistoryFile: "/tmp/readline.tmp", AutoComplete: completer, }) if err != nil { panic(err) } defer l.Close() log.SetOutput(l.Stderr()) for { line, err := l.Readline() if err != nil { break } switch { case line == "help": usage(l.Stderr()) case strings.HasPrefix(line, "say"): line := strings.TrimSpace(line[3:]) if len(line) == 0 { log.Println("say what?") break } go func() { for _ = range time.Tick(time.Second) { log.Println(line) } }() case line == "bye": goto exit case line == "": default: log.Println("you said:", strconv.Quote(line)) } } exit: }