Add --info-command for customizing the input text

Close #3866

CHANGELOG.md

@@ -3,6 +3,13 @@ CHANGELOG
 
 0.54.0
 ------
+- Added `--info-command` option for customizing info text
+  ```sh
+  # Prepend the current cursor position in yellow
+  fzf --info-command='echo -e "\x1b[33;1m$FZF_POS\x1b[m/$FZF_INFO 💛"'
+  ```
+    - `$FZF_INFO` is set to the original info text
+    - ANSI color codes are supported
 - Better cache management and improved rendering for `--tail`
 - Improved `--sync` behavior
     - When `--sync` is provided, fzf will not render the interface until the initial filtering and the associated actions (bound to any of `start`, `load`, `result`, or `focus`) are complete.

man/man1/fzf.1

@@ -452,6 +452,16 @@ Determines the display style of the finder info. (e.g. match counter, loading in
 .BR inline-right:PREFIX "  On the right end of the prompt line with a custom prefix"
 .br
 
+.TP
+.BI "--info-command=" "COMMAND"
+Command to generate the finder info. The command runs synchronously and block
+the UI until completion, so make sure that it's fast. ANSI color codes are
+supported. \fB$FZF_INFO\f$ variable is set to the original info text.
+
+e.g.
+     \fB# Prepend the current cursor position in yellow
+     fzf --info-command='echo -e "\\x1b[33;1m$FZF_POS\\x1b[m/$FZF_INFO 💛"'\fR
+
 .TP
 .B "--no-info"
 A synonym for \fB--info=hidden\fB

src/options.go

@@ -88,6 +88,7 @@ Usage: fzf [options]
     --padding=PADDING       Padding inside border (TRBL | TB,RL | T,RL,B | T,R,B,L)
     --info=STYLE            Finder info style
                             [default|right|hidden|inline[-right][:PREFIX]]
+    --info-command=COMMAND  Command to generate info line
     --separator=STR         String to form horizontal separator on info line
     --no-separator          Hide info line separator
     --scrollbar[=C1[C2]]    Scrollbar character(s) (each for main and preview window)
@@ -443,6 +444,7 @@ type Options struct {
 	FileWord     bool
 	InfoStyle    infoStyle
 	InfoPrefix   string
+	InfoCommand  string
 	Separator    *string
 	JumpLabels   string
 	Prompt       string
@@ -2189,6 +2191,12 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 			if opts.InfoStyle, opts.InfoPrefix, err = parseInfoStyle(str); err != nil {
 				return err
 			}
+		case "--info-command":
+			if opts.InfoCommand, err = nextString(allArgs, &i, "info command required"); err != nil {
+				return err
+			}
+		case "--no-info-command":
+			opts.InfoCommand = ""
 		case "--no-info":
 			opts.InfoStyle = infoHidden
 		case "--inline-info":
@@ -2543,6 +2551,8 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				if opts.InfoStyle, opts.InfoPrefix, err = parseInfoStyle(value); err != nil {
 					return err
 				}
+			} else if match, value := optString(arg, "--info-command="); match {
+				opts.InfoCommand = value
 			} else if match, value := optString(arg, "--separator="); match {
 				opts.Separator = &value
 			} else if match, value := optString(arg, "--scrollbar="); match {

src/terminal.go

@@ -207,6 +207,7 @@ type Status struct {
 // Terminal represents terminal input/output
 type Terminal struct {
 	initDelay          time.Duration
+	infoCommand        string
 	infoStyle          infoStyle
 	infoPrefix         string
 	separator          labelPrinter
@@ -753,6 +754,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 
 	t := Terminal{
 		initDelay:          delay,
+		infoCommand:        opts.InfoCommand,
 		infoStyle:          opts.InfoStyle,
 		infoPrefix:         opts.InfoPrefix,
 		separator:          nil,
@@ -1840,6 +1842,12 @@ func (t *Terminal) printInfo() {
 	if t.failed != nil && t.count == 0 {
 		output = fmt.Sprintf("[Command failed: %s]", *t.failed)
 	}
+	var outputPrinter labelPrinter
+	var outputLen int
+	if t.infoCommand != "" {
+		output = t.executeCommand(t.infoCommand, false, true, true, true, output)
+		outputPrinter, outputLen = t.ansiLabelPrinter(output, &tui.ColInfo, false)
+	}
 
 	if t.infoStyle == infoRight {
 		maxWidth := t.window.Width()
@@ -1847,8 +1855,13 @@ func (t *Terminal) printInfo() {
 			// Need space for spinner and a margin column
 			maxWidth -= 2
 		}
-		output = t.trimMessage(output, maxWidth)
+		var fillLength int
-		fillLength := t.window.Width() - len(output) - 2
+		if outputPrinter == nil {
+			output = t.trimMessage(output, maxWidth)
+			fillLength = t.window.Width() - len(output) - 2
+		} else {
+			fillLength = t.window.Width() - outputLen - 2
+		}
 		if t.reading {
 			if fillLength >= 2 {
 				printSeparator(fillLength-2, true)
@@ -1858,15 +1871,22 @@ func (t *Terminal) printInfo() {
 		} else if fillLength >= 0 {
 			printSeparator(fillLength, true)
 		}
-		t.window.CPrint(tui.ColInfo, output)
+		if outputPrinter == nil {
+			t.window.CPrint(tui.ColInfo, output)
+		} else {
+			outputPrinter(t.window, maxWidth)
+		}
 		t.window.Print(" ") // Margin
 		return
 	}
 
 	if t.infoStyle == infoInlineRight {
+		if outputPrinter == nil {
+			outputLen = util.StringWidth(output)
+		}
 		if len(t.infoPrefix) == 0 {
 			move(line, pos, false)
-			newPos := util.Max(pos, t.window.Width()-util.StringWidth(output)-3)
+			newPos := util.Max(pos, t.window.Width()-outputLen-3)
 			t.window.Print(strings.Repeat(" ", newPos-pos))
 			pos = newPos
 			if pos < t.window.Width() {
@@ -1878,14 +1898,18 @@ func (t *Terminal) printInfo() {
 				pos++
 			}
 		} else {
-			pos = util.Max(pos, t.window.Width()-util.StringWidth(output)-util.StringWidth(t.infoPrefix)-1)
+			pos = util.Max(pos, t.window.Width()-outputLen-util.StringWidth(t.infoPrefix)-1)
 			printInfoPrefix()
 		}
 	}
 
 	maxWidth := t.window.Width() - pos
-	output = t.trimMessage(output, maxWidth)
+	if outputPrinter == nil {
-	t.window.CPrint(tui.ColInfo, output)
+		output = t.trimMessage(output, maxWidth)
+		t.window.CPrint(tui.ColInfo, output)
+	} else {
+		outputPrinter(t.window, maxWidth)
+	}
 
 	if t.infoStyle == infoInlineRight {
 		if t.separatorLen > 0 {
@@ -1895,7 +1919,7 @@ func (t *Terminal) printInfo() {
 		return
 	}
 
-	fillLength := maxWidth - len(output) - 2
+	fillLength := maxWidth - outputLen - 2
 	if fillLength > 0 {
 		t.window.CPrint(tui.ColSeparator, " ")
 		printSeparator(fillLength, false)
@@ -2983,7 +3007,7 @@ func (t *Terminal) fullRedraw() {
 	t.printAll()
 }
 
-func (t *Terminal) executeCommand(template string, forcePlus bool, background bool, capture bool, firstLineOnly bool) string {
+func (t *Terminal) executeCommand(template string, forcePlus bool, background bool, capture bool, firstLineOnly bool, info string) string {
 	line := ""
 	valid, list := t.buildPlusList(template, forcePlus)
 	// 'capture' is used for transform-* and we don't want to
@@ -2994,6 +3018,9 @@ func (t *Terminal) executeCommand(template string, forcePlus bool, background bo
 	command, tempFiles := t.replacePlaceholder(template, forcePlus, string(t.input), list)
 	cmd := t.executor.ExecCommand(command, false)
 	cmd.Env = t.environ()
+	if len(info) > 0 {
+		cmd.Env = append(cmd.Env, "FZF_INFO="+info)
+	}
 	t.executing.Set(true)
 	if !background {
 		// Open a separate handle for tty input
@@ -3021,17 +3048,20 @@ func (t *Terminal) executeCommand(template string, forcePlus bool, background bo
 		}
 
 		t.mutex.Unlock()
-		t.uiMutex.Lock()
+		if len(info) == 0 {
+			t.uiMutex.Lock()
+		}
 		t.tui.Pause(true)
 		cmd.Run()
 		t.tui.Resume(true, false)
 		t.mutex.Lock()
 		t.fullRedraw()
 		t.flush()
-		t.uiMutex.Unlock()
 	} else {
 		t.mutex.Unlock()
-		t.uiMutex.Lock()
+		if len(info) == 0 {
+			t.uiMutex.Lock()
+		}
 		if capture {
 			out, _ := cmd.StdoutPipe()
 			reader := bufio.NewReader(out)
@@ -3048,6 +3078,8 @@ func (t *Terminal) executeCommand(template string, forcePlus bool, background bo
 			cmd.Run()
 		}
 		t.mutex.Lock()
+	}
+	if len(info) == 0 {
 		t.uiMutex.Unlock()
 	}
 	t.executing.Set(false)
@@ -3528,13 +3560,20 @@ func (t *Terminal) Loop() error {
 						t.printList()
 						currentIndex := t.currentIndex()
 						focusChanged := focusedIndex != currentIndex
+						printInfo := false
 						if focusChanged && t.track == trackCurrent {
 							t.track = trackDisabled
-							t.printInfo()
+							printInfo = true
 						}
-						if t.hasFocusActions && focusChanged && currentIndex != t.lastFocus {
+						if (t.hasFocusActions || t.infoCommand != "") && focusChanged && currentIndex != t.lastFocus {
 							t.lastFocus = currentIndex
 							t.eventChan <- tui.Focus.AsEvent()
+							if t.infoCommand != "" {
+								printInfo = true
+							}
+						}
+						if printInfo {
+							t.printInfo()
 						}
 						if focusChanged || version != t.version {
 							version = t.version
@@ -3809,9 +3848,9 @@ func (t *Terminal) Loop() error {
 					}
 				}
 			case actExecute, actExecuteSilent:
-				t.executeCommand(a.a, false, a.t == actExecuteSilent, false, false)
+				t.executeCommand(a.a, false, a.t == actExecuteSilent, false, false, "")
 			case actExecuteMulti:
-				t.executeCommand(a.a, true, false, false, false)
+				t.executeCommand(a.a, true, false, false, false, "")
 			case actInvalid:
 				t.mutex.Unlock()
 				return false
@@ -3852,12 +3891,12 @@ func (t *Terminal) Loop() error {
 					req(reqPreviewRefresh)
 				}
 			case actTransformPrompt:
-				prompt := t.executeCommand(a.a, false, true, true, true)
+				prompt := t.executeCommand(a.a, false, true, true, true, "")
 				t.promptString = prompt
 				t.prompt, t.promptLen = t.parsePrompt(prompt)
 				req(reqPrompt)
 			case actTransformQuery:
-				query := t.executeCommand(a.a, false, true, true, true)
+				query := t.executeCommand(a.a, false, true, true, true, "")
 				t.input = []rune(query)
 				t.cx = len(t.input)
 			case actToggleSort:
@@ -3921,7 +3960,7 @@ func (t *Terminal) Loop() error {
 				t.input = []rune(a.a)
 				t.cx = len(t.input)
 			case actTransformHeader:
-				header := t.executeCommand(a.a, false, true, true, false)
+				header := t.executeCommand(a.a, false, true, true, false, "")
 				if t.changeHeader(header) {
 					req(reqFullRedraw)
 				} else {
@@ -3946,19 +3985,19 @@ func (t *Terminal) Loop() error {
 					req(reqRedrawPreviewLabel)
 				}
 			case actTransform:
-				body := t.executeCommand(a.a, false, true, true, false)
+				body := t.executeCommand(a.a, false, true, true, false, "")
 				if actions, err := parseSingleActionList(strings.Trim(body, "\r\n")); err == nil {
 					return doActions(actions)
 				}
 			case actTransformBorderLabel:
-				label := t.executeCommand(a.a, false, true, true, true)
+				label := t.executeCommand(a.a, false, true, true, true, "")
 				t.borderLabelOpts.label = label
 				if t.border != nil {
 					t.borderLabel, t.borderLabelLen = t.ansiLabelPrinter(label, &tui.ColBorderLabel, false)
 					req(reqRedrawBorderLabel)
 				}
 			case actTransformPreviewLabel:
-				label := t.executeCommand(a.a, false, true, true, true)
+				label := t.executeCommand(a.a, false, true, true, true, "")
 				t.previewLabelOpts.label = label
 				if t.pborder != nil {
 					t.previewLabel, t.previewLabelLen = t.ansiLabelPrinter(label, &tui.ColPreviewLabel, false)

test/test_go.rb

@@ -2978,6 +2978,28 @@ class TestGoFZF < TestBase
     tmux.until { assert_match(%r{     0/100000}, _1[-1]) }
   end
 
+  def test_info_command
+    tmux.send_keys(%(seq 10000 | #{FZF} --separator x --info-command 'echo -e "--\\x1b[33m$FZF_POS\\x1b[m/$FZF_INFO--"'), :Enter)
+    tmux.until { assert_match(%r{^  --1/10000/10000-- xx}, _1[-2]) }
+    tmux.send_keys :Up
+    tmux.until { assert_match(%r{^  --2/10000/10000-- xx}, _1[-2]) }
+  end
+
+  def test_info_command_inline
+    tmux.send_keys(%(seq 10000 | #{FZF} --separator x --info-command 'echo -e "--\\x1b[33m$FZF_POS\\x1b[m/$FZF_INFO--"' --info inline:xx), :Enter)
+    tmux.until { assert_match(%r{^>  xx--1/10000/10000-- xx}, _1[-1]) }
+  end
+
+  def test_info_command_right
+    tmux.send_keys(%(seq 10000 | #{FZF} --separator x --info-command 'echo -e "--\\x1b[33m$FZF_POS\\x1b[m/$FZF_INFO--"' --info right), :Enter)
+    tmux.until { assert_match(%r{xx --1/10000/10000-- *$}, _1[-2]) }
+  end
+
+  def test_info_command_inline_right
+    tmux.send_keys(%(seq 10000 | #{FZF} --info-command 'echo -e "--\\x1b[33m$FZF_POS\\x1b[m/$FZF_INFO--"' --info inline-right), :Enter)
+    tmux.until { assert_match(%r{   --1/10000/10000-- *$}, _1[-1]) }
+  end
+
   def test_prev_next_selected
     tmux.send_keys 'seq 10 | fzf --multi --bind ctrl-n:next-selected,ctrl-p:prev-selected', :Enter
     tmux.until { |lines| assert_equal 10, lines.item_count }