0.40.0

Close #3269

CHANGELOG.md

@@ -1,6 +1,38 @@
 CHANGELOG
 =========
 
+0.40.0
+------
+- Added `zero` event that is triggered when there's no match
+  ```sh
+  # Reload the candidate list when there's no match
+  echo $RANDOM | fzf --bind 'zero:reload(echo $RANDOM)+clear-query' --height 3
+  ```
+- New actions
+    - Added `track` action which makes fzf track the current item when the
+      search result is updated. If the user manually moves the cursor, or the
+      item is not in the updated search result, tracking is automatically
+      disabled. Tracking is useful when you want to see the surrounding items
+      by deleting the query string.
+      ```sh
+      # Narrow down the list with a query, point to a command,
+      # and hit CTRL-T to see its surrounding commands.
+      export FZF_CTRL_R_OPTS="
+        --preview 'echo {}' --preview-window up:3:hidden:wrap
+        --bind 'ctrl-/:toggle-preview'
+        --bind 'ctrl-t:track+clear-query'
+        --bind 'ctrl-y:execute-silent(echo -n {2..} | pbcopy)+abort'
+        --color header:italic
+        --header 'Press CTRL-Y to copy command into clipboard'"
+      ```
+    - Added `change-header(...)`
+    - Added `transform-header(...)`
+    - Added `toggle-track` action
+- Fixed `--track` behavior when used with `--tac`
+    - However, using `--track` with `--tac` is not recommended. The resulting
+      behavior can be very confusing.
+- Bug fixes and improvements
+
 0.39.0
 ------
 - Added `one` event that is triggered when there's only one match
@@ -176,7 +208,7 @@ CHANGELOG
 - Added color name `preview-label` for `--preview-label` (defaults to `label`
   for `--border-label`)
 - Better support for (Windows) terminals where each box-drawing character
-  takes 2 columns. Set `RUNEWIDTH_EASTASIAN` environment variable to `1`.
+  takes 2 columns. Set `RUNEWIDTH_EASTASIAN` environment variable to `0` or `1`.
     - On Vim, the variable will be automatically set if `&ambiwidth` is `double`
 - Behavior changes
     - fzf will always execute the preview command if the command template

bin/fzf-tmux

@@ -180,7 +180,7 @@ trap 'cleanup' EXIT
 envs="export TERM=$TERM "
 if [[ "$opt" =~ "-E" ]]; then
   tmux_version=$(tmux -V | sed 's/[^0-9.]//g')
-  if [[ $(bc -l <<< "$tmux_version > 3.2") = 1 ]]; then
+  if [[ $(awk '{print ($1 > 3.2)}' <<< "$tmux_version" 2> /dev/null || bc -l <<< "$tmux_version > 3.2") = 1 ]]; then
     FZF_DEFAULT_OPTS="--border $FZF_DEFAULT_OPTS"
     opt="-B $opt"
   elif [[ $tmux_version = 3.2 ]]; then

go.mod

@@ -7,8 +7,8 @@ require (
 	github.com/mattn/go-shellwords v1.0.12
 	github.com/rivo/uniseg v0.4.4
 	github.com/saracen/walker v0.1.3
-	golang.org/x/sys v0.6.0
+	golang.org/x/sys v0.7.0
-	golang.org/x/term v0.6.0
+	golang.org/x/term v0.7.0
 )
 
 require (

go.sum

@@ -32,12 +32,12 @@ golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.6.0 h1:MVltZSvRTcU2ljQOhs94SXPftV6DCNnZViHeQps87pQ=
+golang.org/x/sys v0.7.0 h1:3jlCCIQZPdOYu1h8BkNvLz8Kgwtae2cagcG/VamtZRU=
-golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
-golang.org/x/term v0.6.0 h1:clScbb1cHjoCkyRbWwBEUZ5H/tIFu5TAXIqaZD0Gcjw=
+golang.org/x/term v0.7.0 h1:BEvjmm5fURWqcfbSKTdpkDXYBrUS1c0m8agp14W48vQ=
-golang.org/x/term v0.6.0/go.mod h1:m6U89DPEgQRMq3DNkDClhWw02AUbt2daBVO4cn4Hv9U=
+golang.org/x/term v0.7.0/go.mod h1:P32HKFT3hSsZrRxla30E9HqToFYAQPCMs/zFMBUFqPY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=

install

@@ -2,7 +2,7 @@
 
 set -u
 
-version=0.39.0
+version=0.40.0
 auto_completion=
 key_bindings=
 update_config=2

install.ps1

@@ -1,4 +1,4 @@
-$version="0.39.0"
+$version="0.40.0"
 
 $fzf_base=Split-Path -Parent $MyInvocation.MyCommand.Definition
 

main.go

@@ -5,7 +5,7 @@ import (
 	"github.com/junegunn/fzf/src/protector"
 )
 
-var version string = "0.39"
+var version string = "0.40"
 var revision string = "devel"
 
 func main() {

man/man1/fzf-tmux.1

@@ -21,7 +21,7 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ..
-.TH fzf-tmux 1 "Apr 2023" "fzf 0.39.0" "fzf-tmux - open fzf in tmux split pane"
+.TH fzf-tmux 1 "May 2023" "fzf 0.40.0" "fzf-tmux - open fzf in tmux split pane"
 
 .SH NAME
 fzf-tmux - open fzf in tmux split pane

man/man1/fzf.1

@@ -21,7 +21,7 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ..
-.TH fzf 1 "Apr 2023" "fzf 0.39.0" "fzf - a command-line fuzzy finder"
+.TH fzf 1 "May 2023" "fzf 0.40.0" "fzf - a command-line fuzzy finder"
 
 .SH NAME
 fzf - a command-line fuzzy finder
@@ -94,7 +94,10 @@ Do not sort the result
 .TP
 .B "--track"
 Make fzf track the current selection when the result list is updated.
-This can be useful when browsing logs using fzf with sorting disabled.
+This can be useful when browsing logs using fzf with sorting disabled. It is
+not recommended to use this option with \fB--tac\fR as the resulting behavior
+can be confusing. Also, consider using \fBtrack\fR action instead of this
+option.
 
 .RS
 e.g.
@@ -241,8 +244,9 @@ Draw border around the finder
 .br
 
 If you use a terminal emulator where each box-drawing character takes
-2 columns, try setting \fBRUNEWIDTH_EASTASIAN\fR to \fB1\fR. If the border is
+2 columns, try setting \fBRUNEWIDTH_EASTASIAN\fR environment variable to
-still not properly rendered, set \fB--no-unicode\fR.
+\fB0\fR or \fB1\fR. If the border is still not properly rendered, set
+\fB--no-unicode\fR.
 
 .TP
 .BI "--border-label" [=LABEL]
@@ -1004,6 +1008,17 @@ e.g.
      \fB# Automatically select the only match
      seq 10 | fzf --bind one:accept\fR
 .RE
+\fIzero\fR
+.RS
+Triggered when there's no match. \fBzero:abort\fR binding is comparable to
+\fB--exit-0\fR option, but the difference is that \fB--exit-0\fR is only
+effective before the interactive finder starts but \fBzero\fR event is
+triggered by the interactive finder.
+
+e.g.
+     \fB# Reload the candidate list when there's no match
+     echo $RANDOM | fzf --bind 'zero:reload(echo $RANDOM)+clear-query' --height 3\fR
+.RE
 
 \fIbackward-eof\fR
 .RS
@@ -1030,6 +1045,7 @@ A key or an event can be bound to one or more of the following actions.
     \fBbeginning-of-line\fR            \fIctrl-a  home\fR
     \fBcancel\fR                       (clear query string if not empty, abort fzf otherwise)
     \fBchange-border-label(...)\fR     (change \fB--border-label\fR to the given string)
+    \fBchange-header(...)\fR           (change header to the given string; doesn't affect \fB--header-lines\fR)
     \fBchange-preview(...)\fR          (change \fB--preview\fR option)
     \fBchange-preview-label(...)\fR    (change \fB--preview-label\fR to the given string)
     \fBchange-preview-window(...)\fR   (change \fB--preview-window\fR option; rotate through the multiple option sets separated by '|')
@@ -1097,8 +1113,11 @@ A key or an event can be bound to one or more of the following actions.
     \fBtoggle-preview-wrap\fR
     \fBtoggle-search\fR                (toggle search functionality)
     \fBtoggle-sort\fR
+    \fBtoggle-track\fR
     \fBtoggle+up\fR                    \fIbtab    (shift-tab)\fR
+    \fBtrack\fR                        (track the current item; automatically disabled if focus changes)
     \fBtransform-border-label(...)\fR  (transform border label using an external command)
+    \fBtransform-header(...)\fR        (transform header using an external command)
     \fBtransform-preview-label(...)\fR (transform preview label using an external command)
     \fBtransform-prompt(...)\fR        (transform prompt string using an external command)
     \fBtransform-query(...)\fR         (transform query string using an external command)

plugin/fzf.vim

@@ -164,7 +164,7 @@ function s:get_version(bin)
   if has_key(s:versions, a:bin)
     return s:versions[a:bin]
   end
-  let command = (&shell =~ 'powershell' ? '&' : '') . s:fzf_call('shellescape', a:bin) . ' --version --no-height'
+  let command = (&shell =~ 'powershell\|pwsh' ? '&' : '') . s:fzf_call('shellescape', a:bin) . ' --version --no-height'
   let output = systemlist(command)
   if v:shell_error || empty(output)
     return ''

src/core.go

@@ -299,10 +299,12 @@ func Run(opts *Options, version string, revision string) {
 
 				case EvtSearchNew:
 					var command *string
+					var changed bool
 					switch val := value.(type) {
 					case searchRequest:
 						sort = val.sort
 						command = val.command
+						changed = val.changed
 						if command != nil {
 							useSnapshot = val.sync
 						}
@@ -314,10 +316,17 @@ func Run(opts *Options, version string, revision string) {
 						} else {
 							restart(*command)
 						}
+					}
+					if !changed {
 						break
 					}
 					if !useSnapshot {
-						snapshot, _ = chunkList.Snapshot()
+						newSnapshot, _ := chunkList.Snapshot()
+						// We want to avoid showing empty list when reload is triggered
+						// and the query string is changed at the same time i.e. command != nil && changed
+						if command == nil || len(newSnapshot) > 0 {
+							snapshot = newSnapshot
+						}
 					}
 					reset := !useSnapshot && clearCache()
 					matcher.Reset(snapshot, input(reset), true, !reading, sort, reset)

src/merger.go

@@ -60,17 +60,30 @@ func (mg *Merger) Length() int {
 	return mg.count
 }
 
+func (mg *Merger) First() Result {
+	if mg.tac && !mg.sorted {
+		return mg.Get(mg.count - 1)
+	}
+	return mg.Get(0)
+}
+
 // FindIndex returns the index of the item with the given item index
 func (mg *Merger) FindIndex(itemIndex int32) int {
+	index := -1
 	if mg.pass {
-		return int(itemIndex)
+		index = int(itemIndex)
+		if mg.tac {
+			index = mg.count - index - 1
 		}
+	} else {
 		for i := 0; i < mg.count; i++ {
 			if mg.Get(i).item.Index() == itemIndex {
-			return i
+				index = i
+				break
 			}
 		}
-	return -1
+	}
+	return index
 }
 
 // Get returns the pointer to the Result object indexed by the given integer

src/options.go

@@ -165,6 +165,14 @@ func defaultMargin() [4]sizeSpec {
 	return [4]sizeSpec{}
 }
 
+type trackOption int
+
+const (
+	trackDisabled trackOption = iota
+	trackEnabled
+	trackCurrent
+)
+
 type windowPosition int
 
 const (
@@ -267,7 +275,7 @@ type Options struct {
 	WithNth      []Range
 	Delimiter    Delimiter
 	Sort         int
-	Track        bool
+	Track        trackOption
 	Tac          bool
 	Criteria     []criterion
 	Multi        int
@@ -340,7 +348,7 @@ func defaultOptions() *Options {
 		WithNth:      make([]Range, 0),
 		Delimiter:    Delimiter{},
 		Sort:         1000,
-		Track:        false,
+		Track:        trackDisabled,
 		Tac:          false,
 		Criteria:     []criterion{byScore, byLength},
 		Multi:        0,
@@ -624,6 +632,8 @@ func parseKeyChordsImpl(str string, message string, exit func(string)) map[tui.E
 			add(tui.Focus)
 		case "one":
 			add(tui.One)
+		case "zero":
+			add(tui.Zero)
 		case "alt-enter", "alt-return":
 			chords[tui.CtrlAltKey('m')] = key
 		case "alt-space":
@@ -927,7 +937,7 @@ const (
 
 func init() {
 	executeRegexp = regexp.MustCompile(
-		`(?si)[:+](become|execute(?:-multi|-silent)?|reload(?:-sync)?|preview|(?:change|transform)-(?:query|prompt|border-label|preview-label)|change-preview-window|change-preview|(?:re|un)bind|pos|put)`)
+		`(?si)[:+](become|execute(?:-multi|-silent)?|reload(?:-sync)?|preview|(?:change|transform)-(?:header|query|prompt|border-label|preview-label)|change-preview-window|change-preview|(?:re|un)bind|pos|put)`)
 	splitRegexp = regexp.MustCompile("[,:]+")
 	actionNameRegexp = regexp.MustCompile("(?i)^[a-z-]+")
 }
@@ -1083,6 +1093,10 @@ func parseActionList(masked string, original string, prevActions []*action, putA
 			appendAction(actToggleAll)
 		case "toggle-search":
 			appendAction(actToggleSearch)
+		case "toggle-track":
+			appendAction(actToggleTrack)
+		case "track":
+			appendAction(actTrack)
 		case "select":
 			appendAction(actSelect)
 		case "select-all":
@@ -1247,6 +1261,8 @@ func isExecuteAction(str string) actionType {
 		return actPreview
 	case "change-border-label":
 		return actChangeBorderLabel
+	case "change-header":
+		return actChangeHeader
 	case "change-preview-label":
 		return actChangePreviewLabel
 	case "change-preview-window":
@@ -1271,6 +1287,8 @@ func isExecuteAction(str string) actionType {
 		return actTransformBorderLabel
 	case "transform-preview-label":
 		return actTransformPreviewLabel
+	case "transform-header":
+		return actTransformHeader
 	case "transform-prompt":
 		return actTransformPrompt
 	case "transform-query":
@@ -1568,9 +1586,9 @@ func parseOptions(opts *Options, allArgs []string) {
 		case "+s", "--no-sort":
 			opts.Sort = 0
 		case "--track":
-			opts.Track = true
+			opts.Track = trackEnabled
 		case "--no-track":
-			opts.Track = false
+			opts.Track = trackDisabled
 		case "--tac":
 			opts.Tac = true
 		case "--no-tac":

src/terminal.go

@@ -3,6 +3,7 @@ package fzf
 import (
 	"bufio"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"math"
 	"os"
@@ -183,7 +184,7 @@ type Terminal struct {
 	multi              int
 	sort               bool
 	toggleSort         bool
-	track              bool
+	track              trackOption
 	delimiter          Delimiter
 	expect             map[tui.Event]string
 	keymap             map[tui.Event][]*action
@@ -310,6 +311,7 @@ const (
 	actBackwardWord
 	actCancel
 	actChangeBorderLabel
+	actChangeHeader
 	actChangePreviewLabel
 	actChangePrompt
 	actChangeQuery
@@ -337,6 +339,8 @@ const (
 	actToggleUp
 	actToggleIn
 	actToggleOut
+	actToggleTrack
+	actTrack
 	actDown
 	actUp
 	actPageUp
@@ -355,6 +359,7 @@ const (
 	actTogglePreview
 	actTogglePreviewWrap
 	actTransformBorderLabel
+	actTransformHeader
 	actTransformPreviewLabel
 	actTransformPrompt
 	actTransformQuery
@@ -403,6 +408,7 @@ type searchRequest struct {
 	sort    bool
 	sync    bool
 	command *string
+	changed bool
 }
 
 type previewRequest struct {
@@ -623,7 +629,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		cycle:              opts.Cycle,
 		headerFirst:        opts.HeaderFirst,
 		headerLines:        opts.HeaderLines,
-		header:             header,
+		header:             []string{},
 		header0:            header,
 		ellipsis:           opts.Ellipsis,
 		ansi:               opts.Ansi,
@@ -882,10 +888,21 @@ func reverseStringArray(input []string) []string {
 	return reversed
 }
 
+func (t *Terminal) changeHeader(header string) bool {
+	lines := strings.Split(strings.TrimSuffix(header, "\n"), "\n")
+	switch t.layout {
+	case layoutDefault, layoutReverseList:
+		lines = reverseStringArray(lines)
+	}
+	needFullRedraw := len(t.header0) != len(lines)
+	t.header0 = lines
+	return needFullRedraw
+}
+
 // UpdateHeader updates the header
 func (t *Terminal) UpdateHeader(header []string) {
 	t.mutex.Lock()
-	t.header = append(append([]string{}, t.header0...), header...)
+	t.header = header
 	t.mutex.Unlock()
 	t.reqBox.Set(reqHeader, nil)
 }
@@ -907,8 +924,12 @@ func (t *Terminal) UpdateProgress(progress float32) {
 func (t *Terminal) UpdateList(merger *Merger, reset bool) {
 	t.mutex.Lock()
 	var prevIndex int32 = -1
-	if !reset && t.track && t.merger.Length() > 0 {
+	if !reset && t.track != trackDisabled {
+		if t.merger.Length() > 0 {
 			prevIndex = t.merger.Get(t.cy).item.Index()
+		} else if merger.Length() > 0 {
+			prevIndex = merger.First().item.Index()
+		}
 	}
 	t.progress = 100
 	t.merger = merger
@@ -916,7 +937,7 @@ func (t *Terminal) UpdateList(merger *Merger, reset bool) {
 		t.selected = make(map[int32]selectedItem)
 		t.version++
 	}
-	if t.hasLoadActions && t.triggerLoad {
+	if t.triggerLoad {
 		t.triggerLoad = false
 		t.eventChan <- tui.Load.AsEvent()
 	}
@@ -927,17 +948,29 @@ func (t *Terminal) UpdateList(merger *Merger, reset bool) {
 		if i >= 0 {
 			t.cy = i
 			t.offset = t.cy - pos
+		} else if t.track == trackCurrent {
+			t.track = trackDisabled
+			t.cy = pos
+			t.offset = 0
 		} else if t.cy > count {
 			// Try to keep the vertical position when the list shrinks
 			t.cy = count - util.Min(count, t.maxItems()) + pos
 		}
 	}
-	if !t.reading && t.merger.Length() == 1 {
+	if !t.reading {
+		switch t.merger.Length() {
+		case 0:
+			zero := tui.Zero.AsEvent()
+			if _, prs := t.keymap[zero]; prs {
+				t.eventChan <- zero
+			}
+		case 1:
 			one := tui.One.AsEvent()
 			if _, prs := t.keymap[one]; prs {
 				t.eventChan <- one
 			}
 		}
+	}
 	t.mutex.Unlock()
 	t.reqBox.Set(reqInfo, nil)
 	t.reqBox.Set(reqList, nil)
@@ -1340,7 +1373,7 @@ func (t *Terminal) move(y int, x int, clear bool) {
 	case layoutDefault:
 		y = h - y - 1
 	case layoutReverseList:
-		n := 2 + len(t.header)
+		n := 2 + len(t.header0) + len(t.header)
 		if t.noInfoLine() {
 			n--
 		}
@@ -1460,6 +1493,9 @@ func (t *Terminal) printInfo() {
 			output += " -S"
 		}
 	}
+	if t.track != trackDisabled {
+		output += " +T"
+	}
 	if t.multi > 0 {
 		if t.multi == maxMulti {
 			output += fmt.Sprintf(" (%d)", len(t.selected))
@@ -1485,7 +1521,7 @@ func (t *Terminal) printInfo() {
 }
 
 func (t *Terminal) printHeader() {
-	if len(t.header) == 0 {
+	if len(t.header0)+len(t.header) == 0 {
 		return
 	}
 	max := t.window.Height()
@@ -1496,7 +1532,7 @@ func (t *Terminal) printHeader() {
 		}
 	}
 	var state *ansiState
-	for idx, lineStr := range t.header {
+	for idx, lineStr := range append(append([]string{}, t.header0...), t.header...) {
 		line := idx
 		if !t.headerFirst {
 			line++
@@ -1530,7 +1566,7 @@ func (t *Terminal) printList() {
 		if t.layout == layoutDefault {
 			i = maxy - 1 - j
 		}
-		line := i + 2 + len(t.header)
+		line := i + 2 + len(t.header0) + len(t.header)
 		if t.noInfoLine() {
 			line--
 		}
@@ -1836,7 +1872,7 @@ func (t *Terminal) renderPreviewText(height int, lines []string, lineNo int, unc
 		if ansi != nil {
 			ansi.lbg = -1
 		}
-		line = strings.TrimSuffix(line, "\n")
+		line = strings.TrimRight(line, "\r\n")
 		if lineNo >= height || t.pwindow.Y() == height-1 && t.pwindow.X() > 0 {
 			t.previewed.filled = true
 			t.previewer.scrollable = true
@@ -2268,12 +2304,12 @@ func (t *Terminal) redraw() {
 	t.printAll()
 }
 
-func (t *Terminal) executeCommand(template string, forcePlus bool, background bool, captureFirstLine bool) string {
+func (t *Terminal) executeCommand(template string, forcePlus bool, background bool, capture bool, firstLineOnly bool) string {
 	line := ""
 	valid, list := t.buildPlusList(template, forcePlus)
-	// captureFirstLine is used for transform-{prompt,query} and we don't want to
+	// 'capture' is used for transform-* and we don't want to
 	// return an empty string in those cases
-	if !valid && !captureFirstLine {
+	if !valid && !capture {
 		return line
 	}
 	command := t.replacePlaceholder(template, forcePlus, string(t.input), list)
@@ -2290,12 +2326,17 @@ func (t *Terminal) executeCommand(template string, forcePlus bool, background bo
 		t.redraw()
 		t.refresh()
 	} else {
-		if captureFirstLine {
+		if capture {
 			out, _ := cmd.StdoutPipe()
 			reader := bufio.NewReader(out)
 			cmd.Start()
+			if firstLineOnly {
 				line, _ = reader.ReadString('\n')
 				line = strings.TrimRight(line, "\r\n")
+			} else {
+				bytes, _ := io.ReadAll(reader)
+				line = string(bytes)
+			}
 			cmd.Wait()
 		} else {
 			cmd.Run()
@@ -2706,6 +2747,10 @@ func (t *Terminal) Loop() {
 							currentIndex = currentItem.Index()
 						}
 						focusChanged := focusedIndex != currentIndex
+						if focusChanged && t.track == trackCurrent {
+							t.track = trackDisabled
+							t.printInfo()
+						}
 						if onFocus != nil && focusChanged {
 							t.serverChan <- onFocus
 						}
@@ -2818,7 +2863,7 @@ func (t *Terminal) Loop() {
 			}
 			select {
 			case event = <-t.eventChan:
-				needBarrier = event != tui.Load.AsEvent()
+				needBarrier = !event.Is(tui.Load, tui.One, tui.Zero)
 			case actions = <-t.serverChan:
 				event = tui.Invalid.AsEvent()
 				needBarrier = false
@@ -2913,9 +2958,9 @@ func (t *Terminal) Loop() {
 					}
 				}
 			case actExecute, actExecuteSilent:
-				t.executeCommand(a.a, false, a.t == actExecuteSilent, false)
+				t.executeCommand(a.a, false, a.t == actExecuteSilent, false, false)
 			case actExecuteMulti:
-				t.executeCommand(a.a, true, false, false)
+				t.executeCommand(a.a, true, false, false, false)
 			case actInvalid:
 				t.mutex.Unlock()
 				return false
@@ -2949,11 +2994,11 @@ func (t *Terminal) Loop() {
 					req(reqPreviewRefresh)
 				}
 			case actTransformPrompt:
-				prompt := t.executeCommand(a.a, false, true, true)
+				prompt := t.executeCommand(a.a, false, true, true, true)
 				t.prompt, t.promptLen = t.parsePrompt(prompt)
 				req(reqPrompt)
 			case actTransformQuery:
-				query := t.executeCommand(a.a, false, true, true)
+				query := t.executeCommand(a.a, false, true, true, true)
 				t.input = []rune(query)
 				t.cx = len(t.input)
 			case actToggleSort:
@@ -3002,6 +3047,19 @@ func (t *Terminal) Loop() {
 			case actChangeQuery:
 				t.input = []rune(a.a)
 				t.cx = len(t.input)
+			case actTransformHeader:
+				header := t.executeCommand(a.a, false, true, true, false)
+				if t.changeHeader(header) {
+					req(reqFullRedraw)
+				} else {
+					req(reqHeader)
+				}
+			case actChangeHeader:
+				if t.changeHeader(a.a) {
+					req(reqFullRedraw)
+				} else {
+					req(reqHeader)
+				}
 			case actChangeBorderLabel:
 				if t.border != nil {
 					t.borderLabel, t.borderLabelLen = t.ansiLabelPrinter(a.a, &tui.ColBorderLabel, false)
@@ -3014,13 +3072,13 @@ func (t *Terminal) Loop() {
 				}
 			case actTransformBorderLabel:
 				if t.border != nil {
-					label := t.executeCommand(a.a, false, true, true)
+					label := t.executeCommand(a.a, false, true, true, true)
 					t.borderLabel, t.borderLabelLen = t.ansiLabelPrinter(label, &tui.ColBorderLabel, false)
 					req(reqRedrawBorderLabel)
 				}
 			case actTransformPreviewLabel:
 				if t.pborder != nil {
-					label := t.executeCommand(a.a, false, true, true)
+					label := t.executeCommand(a.a, false, true, true, true)
 					t.previewLabel, t.previewLabelLen = t.ansiLabelPrinter(label, &tui.ColPreviewLabel, false)
 					req(reqRedrawPreviewLabel)
 				}
@@ -3270,6 +3328,19 @@ func (t *Terminal) Loop() {
 				t.paused = !t.paused
 				changed = !t.paused
 				req(reqPrompt)
+			case actToggleTrack:
+				switch t.track {
+				case trackEnabled:
+					t.track = trackDisabled
+				case trackDisabled:
+					t.track = trackEnabled
+				}
+				req(reqInfo)
+			case actTrack:
+				if t.track == trackDisabled {
+					t.track = trackCurrent
+				}
+				req(reqInfo)
 			case actEnableSearch:
 				t.paused = false
 				changed = true
@@ -3347,7 +3418,7 @@ func (t *Terminal) Loop() {
 				// Translate coordinates
 				mx -= t.window.Left()
 				my -= t.window.Top()
-				min := 2 + len(t.header)
+				min := 2 + len(t.header0) + len(t.header)
 				if t.noInfoLine() {
 					min--
 				}
@@ -3552,7 +3623,7 @@ func (t *Terminal) Loop() {
 		t.mutex.Unlock() // Must be unlocked before touching reqBox
 
 		if changed || newCommand != nil {
-			t.eventBox.Set(EvtSearchNew, searchRequest{sort: t.sort, sync: reloadSync, command: newCommand})
+			t.eventBox.Set(EvtSearchNew, searchRequest{sort: t.sort, sync: reloadSync, command: newCommand, changed: changed})
 		}
 		for _, event := range events {
 			t.reqBox.Set(event, nil)
@@ -3616,7 +3687,7 @@ func (t *Terminal) vset(o int) bool {
 }
 
 func (t *Terminal) maxItems() int {
-	max := t.window.Height() - 2 - len(t.header)
+	max := t.window.Height() - 2 - len(t.header0) - len(t.header)
 	if t.noInfoLine() {
 		max++
 	}

src/tui/tui.go

@@ -94,6 +94,7 @@ const (
 	Load
 	Focus
 	One
+	Zero
 
 	AltBS
 
@@ -283,6 +284,15 @@ type Event struct {
 	MouseEvent *MouseEvent
 }
 
+func (e Event) Is(types ...EventType) bool {
+	for _, t := range types {
+		if e.Type == t {
+			return true
+		}
+	}
+	return false
+}
+
 type MouseEvent struct {
 	Y      int
 	X      int

test/test_go.rb

@@ -1865,6 +1865,67 @@ class TestGoFZF < TestBase
     tmux.until { |lines| assert_equal '>', lines.last }
   end
 
+  def test_change_and_transform_header
+    [
+      'space:change-header:$(seq 4)',
+      'space:transform-header:seq 4'
+    ].each_with_index do |binding, i|
+      tmux.send_keys %(seq 3 | #{FZF} --header-lines 2 --header bar --bind "#{binding}"), :Enter
+      expected = <<~OUTPUT
+        > 3
+          2
+          1
+          bar
+          1/1
+        >
+      OUTPUT
+      tmux.until { assert_block(expected, _1) }
+      tmux.send_keys :Space
+      expected = <<~OUTPUT
+        > 3
+          2
+          1
+          1
+          2
+          3
+          4
+          1/1
+        >
+      OUTPUT
+      tmux.until { assert_block(expected, _1) }
+      next unless i.zero?
+
+      teardown
+      setup
+    end
+  end
+
+  def test_change_header
+    tmux.send_keys %(seq 3 | #{FZF} --header-lines 2 --header bar --bind "space:change-header:$(seq 4)"), :Enter
+    expected = <<~OUTPUT
+      > 3
+        2
+        1
+        bar
+        1/1
+      >
+    OUTPUT
+    tmux.until { assert_block(expected, _1) }
+    tmux.send_keys :Space
+    expected = <<~OUTPUT
+      > 3
+        2
+        1
+        1
+        2
+        3
+        4
+        1/1
+      >
+    OUTPUT
+    tmux.until { assert_block(expected, _1) }
+  end
+
   def test_change_query
     tmux.send_keys %(: | #{FZF} --query foo --bind space:change-query:foobar), :Enter
     tmux.until { |lines| assert_equal 0, lines.item_count }
@@ -2681,7 +2742,7 @@ class TestGoFZF < TestBase
   end
 
   def test_track
-    tmux.send_keys "seq 1000 | #{FZF} --query 555 --track", :Enter
+    tmux.send_keys "seq 1000 | #{FZF} --query 555 --track --bind t:toggle-track", :Enter
     tmux.until do |lines|
       assert_equal 1, lines.match_count
       assert_includes lines, '> 555'
@@ -2701,20 +2762,97 @@ class TestGoFZF < TestBase
       assert_equal 1000, lines.match_count
       assert_equal '> 555', lines[index]
     end
+    tmux.send_keys '555'
+    tmux.until do |lines|
+      assert_equal 1, lines.match_count
+      assert_includes lines, '> 555'
+      assert_includes lines[-2], '+T'
+    end
+    tmux.send_keys 't'
+    tmux.until do |lines|
+      refute_includes lines[-2], '+T'
+    end
+    tmux.send_keys :BSpace
+    tmux.until do |lines|
+      assert_equal 28, lines.match_count
+      assert_includes lines, '> 55'
+    end
+    tmux.send_keys :BSpace
+    tmux.until do |lines|
+      assert_equal 271, lines.match_count
+      assert_includes lines, '> 5'
+    end
+    tmux.send_keys 't'
+    tmux.until do |lines|
+      assert_includes lines[-2], '+T'
+    end
+    tmux.send_keys :BSpace
+    tmux.until do |lines|
+      assert_equal 1000, lines.match_count
+      assert_includes lines, '> 5'
+    end
   end
 
-  def test_one
+  def test_track_action
-    tmux.send_keys "seq 10 | #{FZF} --bind 'one:preview:echo {} is the only match'", :Enter
+    tmux.send_keys "seq 1000 | #{FZF} --query 555 --bind t:track", :Enter
+    tmux.until do |lines|
+      assert_equal 1, lines.match_count
+      assert_includes lines, '> 555'
+    end
+    tmux.send_keys :BSpace
+    tmux.until do |lines|
+      assert_equal 28, lines.match_count
+      assert_includes lines, '> 55'
+    end
+    tmux.send_keys :t
+    tmux.until do |lines|
+      assert_includes lines[-2], '+T'
+    end
+    tmux.send_keys :BSpace
+    tmux.until do |lines|
+      assert_equal 271, lines.match_count
+      assert_includes lines, '> 55'
+    end
+
+    # Automatically disabled when the tracking item is no longer visible
+    tmux.send_keys '4'
+    tmux.until do |lines|
+      assert_equal 28, lines.match_count
+      refute_includes lines[-2], '+T'
+    end
+    tmux.send_keys :BSpace
+    tmux.until do |lines|
+      assert_equal 271, lines.match_count
+      assert_includes lines, '> 5'
+    end
+    tmux.send_keys :t
+    tmux.until do |lines|
+      assert_includes lines[-2], '+T'
+    end
+    tmux.send_keys :Up
+    tmux.until do |lines|
+      refute_includes lines[-2], '+T'
+    end
+  end
+
+  def test_one_and_zero
+    tmux.send_keys "seq 10 | #{FZF} --bind 'zero:preview(echo no match),one:preview(echo {} is the only match)'", :Enter
     tmux.send_keys '1'
     tmux.until do |lines|
       assert_equal 2, lines.match_count
       refute(lines.any? { _1.include?('only match') })
+      refute(lines.any? { _1.include?('no match') })
     end
     tmux.send_keys '0'
     tmux.until do |lines|
       assert_equal 1, lines.match_count
       assert(lines.any? { _1.include?('only match') })
     end
+    tmux.send_keys '0'
+    tmux.until do |lines|
+      assert_equal 0, lines.match_count
+      assert(lines.any? { _1.include?('no match') })
+    end
   end
 
   def test_height_range_with_exit_0
@@ -2723,6 +2861,11 @@ class TestGoFZF < TestBase
     tmux.send_keys :c
     tmux.until { |lines| assert_equal 0, lines.match_count }
   end
+
+  def test_reload_and_change
+    tmux.send_keys "(echo foo; echo bar) | #{FZF} --bind 'load:reload-sync(sleep 60)+change-query(bar)'", :Enter
+    tmux.until { |lines| assert_equal 1, lines.match_count }
+  end
 end
 
 module TestShell