Add --ghost=TEXT to display a ghost text when the input is empty

src/terminal.go

@@ -234,6 +234,7 @@ type Terminal struct {
 	wrap               bool
 	wrapSign           string
 	wrapSignWidth      int
+	ghost              string
 	separator          labelPrinter
 	separatorLen       int
 	spinner            []string
@@ -847,6 +848,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 		infoCommand:        opts.InfoCommand,
 		infoStyle:          opts.InfoStyle,
 		infoPrefix:         opts.InfoPrefix,
+		ghost:              opts.Ghost,
 		separator:          nil,
 		spinner:            makeSpinner(opts.Unicode),
 		promptString:       opts.Prompt,
@@ -2359,6 +2361,11 @@ func (t *Terminal) printPrompt() {
 	t.prompt()
 
 	before, after := t.updatePromptOffset()
+	if len(before) == 0 && len(after) == 0 && len(t.ghost) > 0 {
+		w.CPrint(tui.ColInput.WithAttr(tui.Dim), t.ghost)
+		return
+	}
+
 	color := tui.ColInput
 	if t.paused {
 		color = tui.ColDisabled