Extract common popup argument building into popupArgStr

Fix #4732

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,17 @@
+## Contribution Policy
+
+We do not accept pull requests generated primarily by AI without genuine understanding or real-world usage context.
+
+All contributions are expected to demonstrate:
+- A clear understanding of the codebase
+- Alignment with product direction
+- Thoughtful reasoning behind changes
+- Evidence of real-world usage or hands-on experience with the problem
+
+If these expectations are not met, we would prefer to implement the changes ourselves rather than spend time reviewing low-effort submissions.
+
+---
+
+## Acknowledgement
+
+- [ ] I confirm that this PR meets the above expectations and reflects my own understanding and real-world context.

.github/labeler.yml

@@ -0,0 +1,64 @@
+go:
+  - changed-files:
+      - any-glob-to-any-file:
+          - src/**
+          - main.go
+          - go.mod
+          - go.sum
+
+shell:
+  - changed-files:
+      - any-glob-to-any-file:
+          - shell/**
+
+bash:
+  - changed-files:
+      - any-glob-to-any-file:
+          - shell/**/*.bash
+
+zsh:
+  - changed-files:
+      - any-glob-to-any-file:
+          - shell/**/*.zsh
+
+fish:
+  - changed-files:
+      - any-glob-to-any-file:
+          - shell/**/*.fish
+
+vim:
+  - changed-files:
+      - any-glob-to-any-file:
+          - plugin/**
+
+docs:
+  - changed-files:
+      - any-glob-to-any-file:
+          - '*.md'
+          - doc/**
+          - man/**
+
+ci:
+  - changed-files:
+      - any-glob-to-any-file:
+          - .github/**
+
+build:
+  - changed-files:
+      - any-glob-to-any-file:
+          - Makefile
+          - .goreleaser.yml
+          - Dockerfile
+
+test:
+  - changed-files:
+      - any-glob-to-any-file:
+          - test/**
+          - src/**/*_test.go
+
+install:
+  - changed-files:
+      - any-glob-to-any-file:
+          - install
+          - install.ps1
+          - uninstall

.github/workflows/labeler.yml

@@ -0,0 +1,17 @@
+name: Label PRs
+
+on:
+  pull_request_target:
+    types: [opened, synchronize, reopened]
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  label:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/labeler@v6
+        with:
+          configuration-path: .github/labeler.yml

.github/workflows/linux.yml

@@ -5,7 +5,7 @@ on:
   push:
     branches: [ master, devel ]
   pull_request:
-    branches: [ master ]
+    branches: [ master, devel ]
   workflow_dispatch:
 
 permissions:
@@ -44,5 +44,10 @@ jobs:
     - name: Unit test
       run: make test
 
+    - name: Fuzz test
+      run: |
+        go test ./src/algo/ -fuzz=FuzzIndexByteTwo -fuzztime=5s
+        go test ./src/algo/ -fuzz=FuzzLastIndexByteTwo -fuzztime=5s
+
     - name: Integration test
       run: make install && ./install --all && tmux new-session -d && ruby test/runner.rb --verbose

CHANGELOG.md

@@ -1,6 +1,80 @@
 CHANGELOG
 =========
 
+0.71.0
+------
+- Added `--popup` as a new name for `--tmux` with Zellij support
+    - `--popup` starts fzf in a tmux popup or a Zellij floating pane
+    - `--tmux` is now an alias for `--popup`
+    - Requires tmux 3.3+ or Zellij 0.44+
+- Cross-reload item identity with `--id-nth`
+    - Added `--id-nth=NTH` to define item identity fields for cross-reload operations
+    - When a `reload` is triggered with tracking enabled, fzf searches for the tracked item by its identity fields in the new list.
+        - `--track --id-nth ..` tracks by the entire line
+        - `--track --id-nth 1` tracks by the first field
+        - `--track` without `--id-nth` retains the existing index-based tracking behavior
+        - The UI is temporarily blocked (prompt dimmed, input disabled) until the item is found or loading completes.
+            - Press `Escape` or `Ctrl-C` to cancel the blocked state without quitting
+            - Info line shows `+T*` / `+t*` while searching
+    - With `--multi`, selected items are preserved across `reload-sync` by matching their identity fields
+- Performance improvements
+    - The search performance now scales linearly with the number of CPU cores, as we dropped static partitioning to allow better load balancing across threads.
+      ```
+      === query: 'linux' ===
+        [all]   baseline:    17.12ms  current:    14.28ms  (1.20x)  matches: 179966 (12.79%)
+        [1T]    baseline:   136.49ms  current:   137.25ms  (0.99x)  matches: 179966 (12.79%)
+        [2T]    baseline:    75.74ms  current:    68.75ms  (1.10x)  matches: 179966 (12.79%)
+        [4T]    baseline:    41.16ms  current:    34.97ms  (1.18x)  matches: 179966 (12.79%)
+        [8T]    baseline:    32.82ms  current:    17.79ms  (1.84x)  matches: 179966 (12.79%)
+      ```
+    - Improved the cache structure, reducing memory footprint per entry by 86x.
+        - With the reduced per-entry cost, the cache now has broader coverage.
+- Shell integration improvements
+    - bash: CTRL-R now supports multi-select and `shift-delete` to delete history entries (#4715)
+    - fish: Improved command history (CTRL-R) (#4703) (@bitraid)
+- `GET /` HTTP endpoint now includes `positions` field in each match entry, providing the indices of matched characters for external highlighting (#4726)
+- Bug fixes
+    - `--walker=follow` no longer follows symlinks whose target is an ancestor of the walker root, avoiding severe resource exhaustion when a symlink points outside the tree (e.g. Wine's `z:` → `/`) (#4710)
+    - Fixed AWK tokenizer not treating a new line character as whitespace
+    - Fixed `--{accept,with}-nth` removing trailing whitespaces with a non-default `--delimiter`
+    - Fixed OSC8 hyperlinks being mangled when the URL contains unicode characters (#4707)
+    - Fixed `--with-shell` not handling quoted arguments correctly (#4709)
+
+0.70.0
+------
+- Added `change-with-nth` action for dynamically changing the `--with-nth` option.
+    - Requires `--with-nth` to be set initially.
+    - Multiple options separated by `|` can be given to cycle through.
+  ```sh
+  echo -e "a b c\nd e f\ng h i" | fzf --with-nth .. \
+    --bind 'space:change-with-nth(1|2|3|1,3|2,3|)'
+  ```
+- Added `change-header-lines` action for dynamically changing the `--header-lines` option
+- Performance improvements (1.3x to 1.9x faster filtering depending on query)
+  ```
+  === query: 'l' ===
+    [all]   baseline:   168.87ms  current:    95.21ms  (1.77x)  matches: 5069891 (94.78%)
+    [1T]    baseline:  1652.22ms  current:   841.40ms  (1.96x)  matches: 5069891 (94.78%)
+
+  === query: 'lin' ===
+    [all]   baseline:   343.27ms  current:   252.59ms  (1.36x)  matches: 3516507 (65.74%)
+    [1T]    baseline:  3199.89ms  current:  2230.64ms  (1.43x)  matches: 3516507 (65.74%)
+
+  === query: 'linux' ===
+    [all]   baseline:    85.47ms  current:    63.72ms  (1.34x)  matches: 307229 (5.74%)
+    [1T]    baseline:   774.64ms  current:   589.32ms  (1.31x)  matches: 307229 (5.74%)
+
+  === query: 'linuxlinux' ===
+    [all]   baseline:    55.13ms  current:    35.67ms  (1.55x)  matches: 12230 (0.23%)
+    [1T]    baseline:   461.99ms  current:   332.38ms  (1.39x)  matches: 12230 (0.23%)
+
+  === query: 'linuxlinuxlinux' ===
+    [all]   baseline:    51.77ms  current:    32.53ms  (1.59x)  matches: 865 (0.02%)
+    [1T]    baseline:   409.99ms  current:   296.33ms  (1.38x)  matches: 865 (0.02%)
+  ```
+- Fixed `nth` attribute merge order to respect precedence hierarchy (#4697)
+- bash: Replaced `printf` with builtin `printf` to bypass local indirections (#4684) (@DarrenBishop)
+
 0.68.0
 ------
 - Implemented word wrapping in the list section

install

@@ -2,7 +2,7 @@
 
 set -u
 
-version=0.68.0
+version=0.70.0
 auto_completion=
 key_bindings=
 update_config=2

install.ps1

@@ -1,4 +1,4 @@
-$version="0.68.0"
+$version="0.70.0"
 
 $fzf_base=Split-Path -Parent $MyInvocation.MyCommand.Definition
 

main.go

@@ -11,7 +11,7 @@ import (
 	"github.com/junegunn/fzf/src/protector"
 )
 
-var version = "0.68"
+var version = "0.70"
 var revision = "devel"
 
 //go:embed shell/key-bindings.bash

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 "Feb 2026" "fzf 0.68.0" "fzf\-tmux - open fzf in tmux split pane"
+.TH fzf\-tmux 1 "Mar 2026" "fzf 0.70.0" "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 "Feb 2026" "fzf 0.68.0" "fzf - a command-line fuzzy finder"
+.TH fzf 1 "Mar 2026" "fzf 0.70.0" "fzf - a command-line fuzzy finder"
 
 .SH NAME
 fzf - a command-line fuzzy finder
@@ -134,6 +134,14 @@ e.g.
      # Use template to rearrange fields
      echo foo,bar,baz | fzf --delimiter , --with-nth '{n},{1},{3},{2},{1..2}'
 .RE
+.RS
+
+\fBchange\-with\-nth\fR action is only available when \fB\-\-with\-nth\fR is set.
+When \fB\-\-with\-nth\fR is used, fzf retains the original input lines in memory
+so they can be re\-transformed on the fly (e.g. \fB\-\-with\-nth ..\fR to keep
+the original presentation). This increases memory usage, so only use
+\fB\-\-with\-nth\fR when you actually need field transformation.
+.RE
 .TP
 .BI "\-\-accept\-nth=" "N[,..] or TEMPLATE"
 Define which fields to print on accept. The last delimiter is stripped from the
@@ -407,25 +415,26 @@ layout options so that the specified number of items are visible in the list
 section (default: \fB10+\fR).
 Ignored when \fB\-\-height\fR is not specified or set as an absolute value.
 .TP
-.BI "\-\-tmux" "[=[center|top|bottom|left|right][,SIZE[%]][,SIZE[%]][,border-native]]"
-Start fzf in a tmux popup (default \fBcenter,50%\fR). Requires tmux 3.3 or
-later. This option is ignored if you are not running fzf inside tmux.
+.BI "\-\-popup" "[=[center|top|bottom|left|right][,SIZE[%]][,SIZE[%]][,border-native]]"
+Start fzf in a tmux popup or in a Zellij floating pane (default
+\fBcenter,50%\fR). Requires tmux 3.3+ or Zellij 0.44+. This option is ignored if you
+are not running fzf inside tmux or Zellij. \fB\-\-tmux\fR is an alias for this option.
 
 e.g.
   \fB# Popup in the center with 70% width and height
-  fzf \-\-tmux 70%
+  fzf \-\-popup 70%
 
   # Popup on the left with 40% width and 100% height
-  fzf \-\-tmux right,40%
+  fzf \-\-popup right,40%
 
   # Popup on the bottom with 100% width and 30% height
-  fzf \-\-tmux bottom,30%
+  fzf \-\-popup bottom,30%
 
   # Popup on the top with 80% width and 40% height
-  fzf \-\-tmux top,80%,40%
+  fzf \-\-popup top,80%,40%
 
-  # Popup with a native tmux border in the center with 80% width and height
-  fzf \-\-tmux center,80%,border\-native\fR
+  # Popup with a native tmux or Zellij border in the center with 80% width and height
+  fzf \-\-popup center,80%,border\-native\fR
 
 .SS LAYOUT
 .TP
@@ -609,17 +618,53 @@ Disable multi-line display of items when using \fB\-\-read0\fR
 .B "\-\-raw"
 Enable raw mode where non-matching items are also displayed in a dimmed color.
 .TP
-.B "\-\-track"
+.BI "\-\-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. 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.
+can be confusing.
+
+When \fB\-\-id\-nth\fR is also set, fzf enables field\-based tracking across
+\fBreload\fRs. See \fB\-\-id\-nth\fR for details.
+
+Without \fB\-\-id\-nth\fR, \fB\-\-track\fR uses index\-based tracking that
+does not persist across reloads.
 
 .RS
 e.g.
-     \fBgit log \-\-oneline \-\-graph \-\-color=always | nl |
+     \fB# Index\-based tracking (does not persist across reloads)
+     git log \-\-oneline \-\-graph \-\-color=always | nl |
          fzf \-\-ansi \-\-track \-\-no\-sort \-\-layout=reverse\-list\fR
+
+     \fB# Track by first field (e.g. pod name) across reloads
+     kubectl get pods | fzf \-\-track \-\-id\-nth 1 \-\-header\-lines=1 \\
+         \-\-bind 'ctrl\-r:reload:kubectl get pods'\fR
+.RE
+.TP
+.BI "\-\-id\-nth=" "N[,..]"
+Define item identity fields for cross\-reload operations. When set, fzf
+uses the specified fields to identify items across \fBreload\fR and
+\fBreload\-sync\fR.
+
+With \fB\-\-track\fR, fzf extracts the tracking key from the current item
+using the nth expression and searches for a matching item in the reloaded list.
+While searching, the UI is blocked (query input and cursor movement are
+disabled, and the prompt is dimmed). With \fBreload\fR, the blocked state
+clears as soon as the match is found in the stream. With \fBreload\-sync\fR,
+the blocked state persists until the entire stream is complete. Press
+\fBEscape\fR or \fBCtrl\-C\fR to cancel the blocked state without quitting fzf.
+
+The info line shows \fB+T*\fR (or \fB+t*\fR for one\-off tracking) while
+the search is in progress.
+
+With \fB\-\-multi\fR, selected items are preserved across \fBreload\-sync\fR
+by matching their identity fields in the reloaded list.
+
+.RS
+e.g.
+     \fB# Track and preserve selections by pod name across reloads
+     kubectl get pods | fzf \-\-multi \-\-track \-\-id\-nth 1 \-\-header\-lines=1 \\
+         \-\-bind 'ctrl\-r:reload\-sync:kubectl get pods'\fR
 .RE
 .TP
 .B "\-\-tac"
@@ -1229,6 +1274,18 @@ Here is an example script that uses a Unix socket instead of a TCP port.
     curl --unix-socket /tmp/fzf.sock http -d up
     \fR
 
+.TP
+.BI "\-\-threads=" "N"
+Number of matcher threads to use. The default value is
+\fBmin(8 * NUM_CPU, 32)\fR.
+.TP
+.BI "\-\-bench=" "DURATION"
+Repeatedly run \fB\-\-filter\fR for the given duration and print timing
+statistics. Must be used with \fB\-\-filter\fR.
+
+e.g.
+     \fBcat /usr/share/dict/words | fzf \-\-filter abc \-\-bench 10s\fR
+
 .SS DIRECTORY TRAVERSAL
 .TP
 .B "\-\-walker=[file][,dir][,follow][,hidden]"
@@ -1398,6 +1455,8 @@ fzf exports the following environment variables to its child processes.
 .br
 .BR FZF_NTH "             Current \-\-nth option"
 .br
+.BR FZF_WITH_NTH "        Current \-\-with\-nth option"
+.br
 .BR FZF_PROMPT "          Prompt string"
 .br
 .BR FZF_GHOST "           Ghost string"
@@ -1881,12 +1940,14 @@ A key or an event can be bound to one or more of the following actions.
     \fBchange\-border\-label(...)\fR     (change \fB\-\-border\-label\fR to the given string)
     \fBchange\-ghost(...)\fR            (change ghost text to the given string)
     \fBchange\-header(...)\fR           (change header to the given string; doesn't affect \fB\-\-header\-lines\fR)
+    \fBchange\-header\-lines(N)\fR       (change the number of \fB\-\-header\-lines\fR)
     \fBchange\-header\-label(...)\fR     (change \fB\-\-header\-label\fR to the given string)
     \fBchange\-input\-label(...)\fR      (change \fB\-\-input\-label\fR to the given string)
     \fBchange\-list\-label(...)\fR       (change \fB\-\-list\-label\fR to the given string)
     \fBchange\-multi\fR                 (enable multi-select mode with no limit)
     \fBchange\-multi(...)\fR            (enable multi-select mode with a limit or disable it with 0)
     \fBchange\-nth(...)\fR              (change \fB\-\-nth\fR option; rotate through the multiple options separated by '|')
+    \fBchange\-with\-nth(...)\fR         (change \fB\-\-with\-nth\fR option; rotate through the multiple options separated by '|')
     \fBchange\-pointer(...)\fR          (change \fB\-\-pointer\fR option)
     \fBchange\-preview(...)\fR          (change \fB\-\-preview\fR option)
     \fBchange\-preview\-label(...)\fR    (change \fB\-\-preview\-label\fR to the given string)
@@ -1987,10 +2048,12 @@ A key or an event can be bound to one or more of the following actions.
     \fBtransform\-border\-label(...)\fR  (transform border label using an external command)
     \fBtransform\-ghost(...)\fR         (transform ghost text using an external command)
     \fBtransform\-header(...)\fR        (transform header using an external command)
+    \fBtransform\-header\-lines(...)\fR  (transform the number of \fB\-\-header\-lines\fR using an external command)
     \fBtransform\-header\-label(...)\fR  (transform header label using an external command)
     \fBtransform\-input\-label(...)\fR   (transform input label using an external command)
     \fBtransform\-list\-label(...)\fR    (transform list label using an external command)
     \fBtransform\-nth(...)\fR           (transform nth using an external command)
+    \fBtransform\-with\-nth(...)\fR      (transform with-nth using an external command)
     \fBtransform\-pointer(...)\fR       (transform pointer 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)

shell/common.sh

@@ -1,9 +1,9 @@
 __fzf_defaults() {
   # $1: Prepend to FZF_DEFAULT_OPTS_FILE and FZF_DEFAULT_OPTS
   # $2: Append to FZF_DEFAULT_OPTS_FILE and FZF_DEFAULT_OPTS
-  printf '%s\n' "--height ${FZF_TMUX_HEIGHT:-40%} --min-height 20+ --bind=ctrl-z:ignore $1"
+  builtin printf '%s\n' "--height ${FZF_TMUX_HEIGHT:-40%} --min-height 20+ --bind=ctrl-z:ignore $1"
   command cat "${FZF_DEFAULT_OPTS_FILE-}" 2> /dev/null
-  printf '%s\n' "${FZF_DEFAULT_OPTS-} $2"
+  builtin printf '%s\n' "${FZF_DEFAULT_OPTS-} $2"
 }
 
 __fzf_exec_awk() {

shell/completion.bash

@@ -38,9 +38,9 @@ if [[ $- =~ i ]]; then
 # the changes. See code comments in "common.sh" for the implementation details.
 
 __fzf_defaults() {
-  printf '%s\n' "--height ${FZF_TMUX_HEIGHT:-40%} --min-height 20+ --bind=ctrl-z:ignore $1"
+  builtin printf '%s\n' "--height ${FZF_TMUX_HEIGHT:-40%} --min-height 20+ --bind=ctrl-z:ignore $1"
   command cat "${FZF_DEFAULT_OPTS_FILE-}" 2> /dev/null
-  printf '%s\n' "${FZF_DEFAULT_OPTS-} $2"
+  builtin printf '%s\n' "${FZF_DEFAULT_OPTS-} $2"
 }
 
 __fzf_exec_awk() {
@@ -81,7 +81,7 @@ __fzf_orig_completion() {
       f="${BASH_REMATCH[2]}"
       cmd="${BASH_REMATCH[3]}"
       [[ $f == _fzf_* ]] && continue
-      printf -v "_fzf_orig_completion_${cmd//[^A-Za-z0-9_]/_}" "%s" "${comp} %s ${cmd} #${f}"
+      builtin printf -v "_fzf_orig_completion_${cmd//[^A-Za-z0-9_]/_}" "%s" "${comp} %s ${cmd} #${f}"
       if [[ $l == *" -o nospace "* ]] && [[ ${__fzf_nospace_commands-} != *" $cmd "* ]]; then
         __fzf_nospace_commands="${__fzf_nospace_commands-} $cmd "
       fi
@@ -111,7 +111,7 @@ __fzf_orig_completion_instantiate() {
   orig="${!orig_var-}"
   orig="${orig%#*}"
   [[ $orig == *' %s '* ]] || return 1
-  printf -v REPLY "$orig" "$func"
+  builtin printf -v REPLY "$orig" "$func"
 }
 
 _fzf_opts_completion() {
@@ -161,6 +161,7 @@ _fzf_opts_completion() {
     --history
     --history-size
     --hscroll-off
+    --id-nth
     --info
     --info-command
     --input-border
@@ -376,7 +377,7 @@ __fzf_generic_path_completion() {
             eval "rest=(${FZF_COMPLETION_PATH_OPTS-})"
           fi
           if declare -F "$1" > /dev/null; then
-            eval "$1 $(printf %q "$dir")" | __fzf_comprun "$4" -q "$leftover" "${rest[@]}"
+            eval "$1 $(builtin printf %q "$dir")" | __fzf_comprun "$4" -q "$leftover" "${rest[@]}"
           else
             if [[ $1 =~ dir ]]; then
               walker=dir,follow
@@ -385,7 +386,7 @@ __fzf_generic_path_completion() {
             fi
             __fzf_comprun "$4" -q "$leftover" --walker "$walker" --walker-root="$dir" "${rest[@]}"
           fi | while read -r item; do
-            printf "%q " "${item%$3}$3"
+            builtin printf "%q " "${item%$3}$3"
           done
         )
         matches=${matches% }
@@ -395,9 +396,9 @@ __fzf_generic_path_completion() {
         else
           COMPREPLY=("$cur")
         fi
-        # To redraw line after fzf closes (printf '\e[5n')
+        # To redraw line after fzf closes (builtin printf '\e[5n')
         bind '"\e[0n": redraw-current-line' 2> /dev/null
-        printf '\e[5n'
+        builtin printf '\e[5n'
         return 0
       fi
       dir=$(command dirname "$dir")
@@ -455,7 +456,7 @@ _fzf_complete() {
       COMPREPLY=("$cur")
     fi
     bind '"\e[0n": redraw-current-line' 2> /dev/null
-    printf '\e[5n'
+    builtin printf '\e[5n'
     return 0
   else
     _fzf_handle_dynamic_completion "$cmd" "${rest[@]}"
@@ -527,7 +528,7 @@ _fzf_proc_completion_post() {
 #     # Set the local attribute for any non-local variable that is set by _known_hosts_real()
 #     local COMPREPLY=()
 #     _known_hosts_real ''
-#     printf '%s\n' "${COMPREPLY[@]}" | command sort -u --version-sort
+#     builtin printf '%s\n' "${COMPREPLY[@]}" | command sort -u --version-sort
 #   }
 if ! declare -F __fzf_list_hosts > /dev/null; then
   __fzf_list_hosts() {

shell/completion.zsh

@@ -102,9 +102,9 @@ if [[ -o interactive ]]; then
 # the changes. See code comments in "common.sh" for the implementation details.
 
 __fzf_defaults() {
-  printf '%s\n' "--height ${FZF_TMUX_HEIGHT:-40%} --min-height 20+ --bind=ctrl-z:ignore $1"
+  builtin printf '%s\n' "--height ${FZF_TMUX_HEIGHT:-40%} --min-height 20+ --bind=ctrl-z:ignore $1"
   command cat "${FZF_DEFAULT_OPTS_FILE-}" 2> /dev/null
-  printf '%s\n' "${FZF_DEFAULT_OPTS-} $2"
+  builtin printf '%s\n' "${FZF_DEFAULT_OPTS-} $2"
 }
 
 __fzf_exec_awk() {

shell/key-bindings.bash

@@ -25,9 +25,9 @@ if [[ $- =~ i ]]; then
 # the changes. See code comments in "common.sh" for the implementation details.
 
 __fzf_defaults() {
-  printf '%s\n' "--height ${FZF_TMUX_HEIGHT:-40%} --min-height 20+ --bind=ctrl-z:ignore $1"
+  builtin printf '%s\n' "--height ${FZF_TMUX_HEIGHT:-40%} --min-height 20+ --bind=ctrl-z:ignore $1"
   command cat "${FZF_DEFAULT_OPTS_FILE-}" 2> /dev/null
-  printf '%s\n' "${FZF_DEFAULT_OPTS-} $2"
+  builtin printf '%s\n' "${FZF_DEFAULT_OPTS-} $2"
 }
 
 __fzf_exec_awk() {
@@ -77,17 +77,31 @@ __fzf_cd__() {
   ) && printf 'builtin cd -- %q' "$(builtin unset CDPATH && builtin cd -- "$dir" && builtin pwd)"
 }
 
+__fzf_history_delete() {
+  [[ -s $1 ]] || return
+
+  local offsets
+  offsets=($(sort -rnu "$1"))
+  for offset in "${offsets[@]}"; do
+    builtin history -d "$offset"
+  done
+}
+
 if command -v perl > /dev/null; then
   __fzf_history__() {
-    local output script
+    local output script deletefile
+    deletefile=$(mktemp)
     script='BEGIN { getc; $/ = "\n\t"; $HISTCOUNT = $ENV{last_hist} + 1 } s/^[ *]//; s/\n/\n\t/gm; print $HISTCOUNT - $. . "\t$_" if !$seen{$_}++'
     output=$(
       set +o pipefail
       builtin fc -lnr -2147483648 |
         last_hist=$(HISTTIMEFORMAT='' builtin history 1) command perl -n -l0 -e "$script" |
-        FZF_DEFAULT_OPTS=$(__fzf_defaults "" "-n2..,.. --scheme=history --bind=ctrl-r:toggle-sort,alt-r:toggle-raw --wrap-sign '"$'\t'"↳ ' --highlight-line ${FZF_CTRL_R_OPTS-} +m --read0") \
+        FZF_DEFAULT_OPTS=$(__fzf_defaults "" "-n2..,.. --scheme=history --bind=ctrl-r:toggle-sort,alt-r:toggle-raw --wrap-sign '"$'\t'"↳ ' --highlight-line --bind 'shift-delete:execute-silent(cat {+f1} >> \"$deletefile\")+exclude-multi' --multi ${FZF_CTRL_R_OPTS-} --read0") \
         FZF_DEFAULT_OPTS_FILE='' $(__fzfcmd) --query "$READLINE_LINE"
-    ) || return
+    )
+    __fzf_history_delete "$deletefile"
+    command rm -f "$deletefile"
+    [[ -n $output ]] || return
     READLINE_LINE=$(command perl -pe 's/^\d*\t//' <<< "$output")
     if [[ -z $READLINE_POINT ]]; then
       echo "$READLINE_LINE"
@@ -97,7 +111,8 @@ if command -v perl > /dev/null; then
   }
 else # awk - fallback for POSIX systems
   __fzf_history__() {
-    local output script
+    local output script deletefile
+    deletefile=$(mktemp)
     [[ $(HISTTIMEFORMAT='' builtin history 1) =~ [[:digit:]]+ ]] # how many history entries
     script='function P(b) { ++n; sub(/^[ *]/, "", b); if (!seen[b]++) { printf "%d\t%s%c", '$((BASH_REMATCH + 1))' - n, b, 0 } }
     NR==1 { b = substr($0, 2); next }
@@ -108,9 +123,12 @@ else # awk - fallback for POSIX systems
       set +o pipefail
       builtin fc -lnr -2147483648 2> /dev/null | # ( $'\t '<lines>$'\n' )* ; <lines> ::= [^\n]* ( $'\n'<lines> )*
         __fzf_exec_awk "$script" |               # ( <counter>$'\t'<lines>$'\000' )*
-        FZF_DEFAULT_OPTS=$(__fzf_defaults "" "-n2..,.. --scheme=history --bind=ctrl-r:toggle-sort,alt-r:toggle-raw --wrap-sign '"$'\t'"↳ ' --highlight-line ${FZF_CTRL_R_OPTS-} +m --read0") \
+        FZF_DEFAULT_OPTS=$(__fzf_defaults "" "-n2..,.. --scheme=history --bind=ctrl-r:toggle-sort,alt-r:toggle-raw --wrap-sign '"$'\t'"↳ ' --highlight-line --bind 'shift-delete:execute-silent(cat {+f1} >> \"$deletefile\")+exclude-multi' --multi ${FZF_CTRL_R_OPTS-} --read0") \
         FZF_DEFAULT_OPTS_FILE='' $(__fzfcmd) --query "$READLINE_LINE"
-    ) || return
+    )
+    __fzf_history_delete "$deletefile"
+    command rm -f "$deletefile"
+    [[ -n $output ]] || return
     READLINE_LINE=${output#*$'\t'}
     if [[ -z $READLINE_POINT ]]; then
       echo "$READLINE_LINE"

shell/key-bindings.zsh

@@ -45,9 +45,9 @@ if [[ -o interactive ]]; then
 # the changes. See code comments in "common.sh" for the implementation details.
 
 __fzf_defaults() {
-  printf '%s\n' "--height ${FZF_TMUX_HEIGHT:-40%} --min-height 20+ --bind=ctrl-z:ignore $1"
+  builtin printf '%s\n' "--height ${FZF_TMUX_HEIGHT:-40%} --min-height 20+ --bind=ctrl-z:ignore $1"
   command cat "${FZF_DEFAULT_OPTS_FILE-}" 2> /dev/null
-  printf '%s\n' "${FZF_DEFAULT_OPTS-} $2"
+  builtin printf '%s\n' "${FZF_DEFAULT_OPTS-} $2"
 }
 
 __fzf_exec_awk() {
@@ -129,7 +129,7 @@ fi
 # CTRL-R - Paste the selected command from history into the command line
 fzf-history-widget() {
   local selected extracted_with_perl=0
-  setopt localoptions noglobsubst noposixbuiltins pipefail no_aliases no_glob no_ksharrays extendedglob 2> /dev/null
+  setopt localoptions noglobsubst noposixbuiltins pipefail no_aliases no_glob no_sh_glob no_ksharrays extendedglob 2> /dev/null
   # Ensure the module is loaded if not already, and the required features, such
   # as the associative 'history' array, which maps event numbers to full history
   # lines, are set. Also, make sure Perl is installed for multi-line output.

src/actiontype_string.go

@@ -30,161 +30,167 @@ func _() {
 	_ = x[actChangeBorderLabel-19]
 	_ = x[actChangeGhost-20]
 	_ = x[actChangeHeader-21]
-	_ = x[actChangeFooter-22]
-	_ = x[actChangeHeaderLabel-23]
-	_ = x[actChangeFooterLabel-24]
-	_ = x[actChangeInputLabel-25]
-	_ = x[actChangeListLabel-26]
-	_ = x[actChangeMulti-27]
-	_ = x[actChangeNth-28]
-	_ = x[actChangePointer-29]
-	_ = x[actChangePreview-30]
-	_ = x[actChangePreviewLabel-31]
-	_ = x[actChangePreviewWindow-32]
-	_ = x[actChangePrompt-33]
-	_ = x[actChangeQuery-34]
-	_ = x[actClearScreen-35]
-	_ = x[actClearQuery-36]
-	_ = x[actClearSelection-37]
-	_ = x[actClose-38]
-	_ = x[actDeleteChar-39]
-	_ = x[actDeleteCharEof-40]
-	_ = x[actEndOfLine-41]
-	_ = x[actFatal-42]
-	_ = x[actForwardChar-43]
-	_ = x[actForwardWord-44]
-	_ = x[actForwardSubWord-45]
-	_ = x[actKillLine-46]
-	_ = x[actKillWord-47]
-	_ = x[actKillSubWord-48]
-	_ = x[actUnixLineDiscard-49]
-	_ = x[actUnixWordRubout-50]
-	_ = x[actYank-51]
-	_ = x[actBackwardKillWord-52]
-	_ = x[actBackwardKillSubWord-53]
-	_ = x[actSelectAll-54]
-	_ = x[actDeselectAll-55]
-	_ = x[actToggle-56]
-	_ = x[actToggleSearch-57]
-	_ = x[actToggleAll-58]
-	_ = x[actToggleDown-59]
-	_ = x[actToggleUp-60]
-	_ = x[actToggleIn-61]
-	_ = x[actToggleOut-62]
-	_ = x[actToggleTrack-63]
-	_ = x[actToggleTrackCurrent-64]
-	_ = x[actToggleHeader-65]
-	_ = x[actToggleWrap-66]
-	_ = x[actToggleWrapWord-67]
-	_ = x[actToggleMultiLine-68]
-	_ = x[actToggleHscroll-69]
-	_ = x[actToggleRaw-70]
-	_ = x[actEnableRaw-71]
-	_ = x[actDisableRaw-72]
-	_ = x[actTrackCurrent-73]
-	_ = x[actToggleInput-74]
-	_ = x[actHideInput-75]
-	_ = x[actShowInput-76]
-	_ = x[actUntrackCurrent-77]
-	_ = x[actDown-78]
-	_ = x[actDownMatch-79]
-	_ = x[actUp-80]
-	_ = x[actUpMatch-81]
-	_ = x[actPageUp-82]
-	_ = x[actPageDown-83]
-	_ = x[actPosition-84]
-	_ = x[actHalfPageUp-85]
-	_ = x[actHalfPageDown-86]
-	_ = x[actOffsetUp-87]
-	_ = x[actOffsetDown-88]
-	_ = x[actOffsetMiddle-89]
-	_ = x[actJump-90]
-	_ = x[actJumpAccept-91]
-	_ = x[actPrintQuery-92]
-	_ = x[actRefreshPreview-93]
-	_ = x[actReplaceQuery-94]
-	_ = x[actToggleSort-95]
-	_ = x[actShowPreview-96]
-	_ = x[actHidePreview-97]
-	_ = x[actTogglePreview-98]
-	_ = x[actTogglePreviewWrap-99]
-	_ = x[actTogglePreviewWrapWord-100]
-	_ = x[actTransform-101]
-	_ = x[actTransformBorderLabel-102]
-	_ = x[actTransformGhost-103]
-	_ = x[actTransformHeader-104]
-	_ = x[actTransformFooter-105]
-	_ = x[actTransformHeaderLabel-106]
-	_ = x[actTransformFooterLabel-107]
-	_ = x[actTransformInputLabel-108]
-	_ = x[actTransformListLabel-109]
-	_ = x[actTransformNth-110]
-	_ = x[actTransformPointer-111]
-	_ = x[actTransformPreviewLabel-112]
-	_ = x[actTransformPrompt-113]
-	_ = x[actTransformQuery-114]
-	_ = x[actTransformSearch-115]
-	_ = x[actTrigger-116]
-	_ = x[actBgTransform-117]
-	_ = x[actBgTransformBorderLabel-118]
-	_ = x[actBgTransformGhost-119]
-	_ = x[actBgTransformHeader-120]
-	_ = x[actBgTransformFooter-121]
-	_ = x[actBgTransformHeaderLabel-122]
-	_ = x[actBgTransformFooterLabel-123]
-	_ = x[actBgTransformInputLabel-124]
-	_ = x[actBgTransformListLabel-125]
-	_ = x[actBgTransformNth-126]
-	_ = x[actBgTransformPointer-127]
-	_ = x[actBgTransformPreviewLabel-128]
-	_ = x[actBgTransformPrompt-129]
-	_ = x[actBgTransformQuery-130]
-	_ = x[actBgTransformSearch-131]
-	_ = x[actBgCancel-132]
-	_ = x[actSearch-133]
-	_ = x[actPreview-134]
-	_ = x[actPreviewTop-135]
-	_ = x[actPreviewBottom-136]
-	_ = x[actPreviewUp-137]
-	_ = x[actPreviewDown-138]
-	_ = x[actPreviewPageUp-139]
-	_ = x[actPreviewPageDown-140]
-	_ = x[actPreviewHalfPageUp-141]
-	_ = x[actPreviewHalfPageDown-142]
-	_ = x[actPrevHistory-143]
-	_ = x[actPrevSelected-144]
-	_ = x[actPrint-145]
-	_ = x[actPut-146]
-	_ = x[actNextHistory-147]
-	_ = x[actNextSelected-148]
-	_ = x[actExecute-149]
-	_ = x[actExecuteSilent-150]
-	_ = x[actExecuteMulti-151]
-	_ = x[actSigStop-152]
-	_ = x[actBest-153]
-	_ = x[actFirst-154]
-	_ = x[actLast-155]
-	_ = x[actReload-156]
-	_ = x[actReloadSync-157]
-	_ = x[actDisableSearch-158]
-	_ = x[actEnableSearch-159]
-	_ = x[actSelect-160]
-	_ = x[actDeselect-161]
-	_ = x[actUnbind-162]
-	_ = x[actRebind-163]
-	_ = x[actToggleBind-164]
-	_ = x[actBecome-165]
-	_ = x[actShowHeader-166]
-	_ = x[actHideHeader-167]
-	_ = x[actBell-168]
-	_ = x[actExclude-169]
-	_ = x[actExcludeMulti-170]
-	_ = x[actAsync-171]
+	_ = x[actChangeHeaderLines-22]
+	_ = x[actChangeFooter-23]
+	_ = x[actChangeHeaderLabel-24]
+	_ = x[actChangeFooterLabel-25]
+	_ = x[actChangeInputLabel-26]
+	_ = x[actChangeListLabel-27]
+	_ = x[actChangeMulti-28]
+	_ = x[actChangeNth-29]
+	_ = x[actChangeWithNth-30]
+	_ = x[actChangePointer-31]
+	_ = x[actChangePreview-32]
+	_ = x[actChangePreviewLabel-33]
+	_ = x[actChangePreviewWindow-34]
+	_ = x[actChangePrompt-35]
+	_ = x[actChangeQuery-36]
+	_ = x[actClearScreen-37]
+	_ = x[actClearQuery-38]
+	_ = x[actClearSelection-39]
+	_ = x[actClose-40]
+	_ = x[actDeleteChar-41]
+	_ = x[actDeleteCharEof-42]
+	_ = x[actEndOfLine-43]
+	_ = x[actFatal-44]
+	_ = x[actForwardChar-45]
+	_ = x[actForwardWord-46]
+	_ = x[actForwardSubWord-47]
+	_ = x[actKillLine-48]
+	_ = x[actKillWord-49]
+	_ = x[actKillSubWord-50]
+	_ = x[actUnixLineDiscard-51]
+	_ = x[actUnixWordRubout-52]
+	_ = x[actYank-53]
+	_ = x[actBackwardKillWord-54]
+	_ = x[actBackwardKillSubWord-55]
+	_ = x[actSelectAll-56]
+	_ = x[actDeselectAll-57]
+	_ = x[actToggle-58]
+	_ = x[actToggleSearch-59]
+	_ = x[actToggleAll-60]
+	_ = x[actToggleDown-61]
+	_ = x[actToggleUp-62]
+	_ = x[actToggleIn-63]
+	_ = x[actToggleOut-64]
+	_ = x[actToggleTrack-65]
+	_ = x[actToggleTrackCurrent-66]
+	_ = x[actToggleHeader-67]
+	_ = x[actToggleWrap-68]
+	_ = x[actToggleWrapWord-69]
+	_ = x[actToggleMultiLine-70]
+	_ = x[actToggleHscroll-71]
+	_ = x[actToggleRaw-72]
+	_ = x[actEnableRaw-73]
+	_ = x[actDisableRaw-74]
+	_ = x[actTrackCurrent-75]
+	_ = x[actToggleInput-76]
+	_ = x[actHideInput-77]
+	_ = x[actShowInput-78]
+	_ = x[actUntrackCurrent-79]
+	_ = x[actDown-80]
+	_ = x[actDownMatch-81]
+	_ = x[actUp-82]
+	_ = x[actUpMatch-83]
+	_ = x[actPageUp-84]
+	_ = x[actPageDown-85]
+	_ = x[actPosition-86]
+	_ = x[actHalfPageUp-87]
+	_ = x[actHalfPageDown-88]
+	_ = x[actOffsetUp-89]
+	_ = x[actOffsetDown-90]
+	_ = x[actOffsetMiddle-91]
+	_ = x[actJump-92]
+	_ = x[actJumpAccept-93]
+	_ = x[actPrintQuery-94]
+	_ = x[actRefreshPreview-95]
+	_ = x[actReplaceQuery-96]
+	_ = x[actToggleSort-97]
+	_ = x[actShowPreview-98]
+	_ = x[actHidePreview-99]
+	_ = x[actTogglePreview-100]
+	_ = x[actTogglePreviewWrap-101]
+	_ = x[actTogglePreviewWrapWord-102]
+	_ = x[actTransform-103]
+	_ = x[actTransformBorderLabel-104]
+	_ = x[actTransformGhost-105]
+	_ = x[actTransformHeader-106]
+	_ = x[actTransformHeaderLines-107]
+	_ = x[actTransformFooter-108]
+	_ = x[actTransformHeaderLabel-109]
+	_ = x[actTransformFooterLabel-110]
+	_ = x[actTransformInputLabel-111]
+	_ = x[actTransformListLabel-112]
+	_ = x[actTransformNth-113]
+	_ = x[actTransformWithNth-114]
+	_ = x[actTransformPointer-115]
+	_ = x[actTransformPreviewLabel-116]
+	_ = x[actTransformPrompt-117]
+	_ = x[actTransformQuery-118]
+	_ = x[actTransformSearch-119]
+	_ = x[actTrigger-120]
+	_ = x[actBgTransform-121]
+	_ = x[actBgTransformBorderLabel-122]
+	_ = x[actBgTransformGhost-123]
+	_ = x[actBgTransformHeader-124]
+	_ = x[actBgTransformHeaderLines-125]
+	_ = x[actBgTransformFooter-126]
+	_ = x[actBgTransformHeaderLabel-127]
+	_ = x[actBgTransformFooterLabel-128]
+	_ = x[actBgTransformInputLabel-129]
+	_ = x[actBgTransformListLabel-130]
+	_ = x[actBgTransformNth-131]
+	_ = x[actBgTransformWithNth-132]
+	_ = x[actBgTransformPointer-133]
+	_ = x[actBgTransformPreviewLabel-134]
+	_ = x[actBgTransformPrompt-135]
+	_ = x[actBgTransformQuery-136]
+	_ = x[actBgTransformSearch-137]
+	_ = x[actBgCancel-138]
+	_ = x[actSearch-139]
+	_ = x[actPreview-140]
+	_ = x[actPreviewTop-141]
+	_ = x[actPreviewBottom-142]
+	_ = x[actPreviewUp-143]
+	_ = x[actPreviewDown-144]
+	_ = x[actPreviewPageUp-145]
+	_ = x[actPreviewPageDown-146]
+	_ = x[actPreviewHalfPageUp-147]
+	_ = x[actPreviewHalfPageDown-148]
+	_ = x[actPrevHistory-149]
+	_ = x[actPrevSelected-150]
+	_ = x[actPrint-151]
+	_ = x[actPut-152]
+	_ = x[actNextHistory-153]
+	_ = x[actNextSelected-154]
+	_ = x[actExecute-155]
+	_ = x[actExecuteSilent-156]
+	_ = x[actExecuteMulti-157]
+	_ = x[actSigStop-158]
+	_ = x[actBest-159]
+	_ = x[actFirst-160]
+	_ = x[actLast-161]
+	_ = x[actReload-162]
+	_ = x[actReloadSync-163]
+	_ = x[actDisableSearch-164]
+	_ = x[actEnableSearch-165]
+	_ = x[actSelect-166]
+	_ = x[actDeselect-167]
+	_ = x[actUnbind-168]
+	_ = x[actRebind-169]
+	_ = x[actToggleBind-170]
+	_ = x[actBecome-171]
+	_ = x[actShowHeader-172]
+	_ = x[actHideHeader-173]
+	_ = x[actBell-174]
+	_ = x[actExclude-175]
+	_ = x[actExcludeMulti-176]
+	_ = x[actAsync-177]
 }
 
-const _actionType_name = "actIgnoreactStartactClickactInvalidactBracketedPasteBeginactBracketedPasteEndactCharactMouseactBeginningOfLineactAbortactAcceptactAcceptNonEmptyactAcceptOrPrintQueryactBackwardCharactBackwardDeleteCharactBackwardDeleteCharEofactBackwardWordactBackwardSubWordactCancelactChangeBorderLabelactChangeGhostactChangeHeaderactChangeFooteractChangeHeaderLabelactChangeFooterLabelactChangeInputLabelactChangeListLabelactChangeMultiactChangeNthactChangePointeractChangePreviewactChangePreviewLabelactChangePreviewWindowactChangePromptactChangeQueryactClearScreenactClearQueryactClearSelectionactCloseactDeleteCharactDeleteCharEofactEndOfLineactFatalactForwardCharactForwardWordactForwardSubWordactKillLineactKillWordactKillSubWordactUnixLineDiscardactUnixWordRuboutactYankactBackwardKillWordactBackwardKillSubWordactSelectAllactDeselectAllactToggleactToggleSearchactToggleAllactToggleDownactToggleUpactToggleInactToggleOutactToggleTrackactToggleTrackCurrentactToggleHeaderactToggleWrapactToggleWrapWordactToggleMultiLineactToggleHscrollactToggleRawactEnableRawactDisableRawactTrackCurrentactToggleInputactHideInputactShowInputactUntrackCurrentactDownactDownMatchactUpactUpMatchactPageUpactPageDownactPositionactHalfPageUpactHalfPageDownactOffsetUpactOffsetDownactOffsetMiddleactJumpactJumpAcceptactPrintQueryactRefreshPreviewactReplaceQueryactToggleSortactShowPreviewactHidePreviewactTogglePreviewactTogglePreviewWrapactTogglePreviewWrapWordactTransformactTransformBorderLabelactTransformGhostactTransformHeaderactTransformFooteractTransformHeaderLabelactTransformFooterLabelactTransformInputLabelactTransformListLabelactTransformNthactTransformPointeractTransformPreviewLabelactTransformPromptactTransformQueryactTransformSearchactTriggeractBgTransformactBgTransformBorderLabelactBgTransformGhostactBgTransformHeaderactBgTransformFooteractBgTransformHeaderLabelactBgTransformFooterLabelactBgTransformInputLabelactBgTransformListLabelactBgTransformNthactBgTransformPointeractBgTransformPreviewLabelactBgTransformPromptactBgTransformQueryactBgTransformSearchactBgCancelactSearchactPreviewactPreviewTopactPreviewBottomactPreviewUpactPreviewDownactPreviewPageUpactPreviewPageDownactPreviewHalfPageUpactPreviewHalfPageDownactPrevHistoryactPrevSelectedactPrintactPutactNextHistoryactNextSelectedactExecuteactExecuteSilentactExecuteMultiactSigStopactBestactFirstactLastactReloadactReloadSyncactDisableSearchactEnableSearchactSelectactDeselectactUnbindactRebindactToggleBindactBecomeactShowHeaderactHideHeaderactBellactExcludeactExcludeMultiactAsync"
+const _actionType_name = "actIgnoreactStartactClickactInvalidactBracketedPasteBeginactBracketedPasteEndactCharactMouseactBeginningOfLineactAbortactAcceptactAcceptNonEmptyactAcceptOrPrintQueryactBackwardCharactBackwardDeleteCharactBackwardDeleteCharEofactBackwardWordactBackwardSubWordactCancelactChangeBorderLabelactChangeGhostactChangeHeaderactChangeHeaderLinesactChangeFooteractChangeHeaderLabelactChangeFooterLabelactChangeInputLabelactChangeListLabelactChangeMultiactChangeNthactChangeWithNthactChangePointeractChangePreviewactChangePreviewLabelactChangePreviewWindowactChangePromptactChangeQueryactClearScreenactClearQueryactClearSelectionactCloseactDeleteCharactDeleteCharEofactEndOfLineactFatalactForwardCharactForwardWordactForwardSubWordactKillLineactKillWordactKillSubWordactUnixLineDiscardactUnixWordRuboutactYankactBackwardKillWordactBackwardKillSubWordactSelectAllactDeselectAllactToggleactToggleSearchactToggleAllactToggleDownactToggleUpactToggleInactToggleOutactToggleTrackactToggleTrackCurrentactToggleHeaderactToggleWrapactToggleWrapWordactToggleMultiLineactToggleHscrollactToggleRawactEnableRawactDisableRawactTrackCurrentactToggleInputactHideInputactShowInputactUntrackCurrentactDownactDownMatchactUpactUpMatchactPageUpactPageDownactPositionactHalfPageUpactHalfPageDownactOffsetUpactOffsetDownactOffsetMiddleactJumpactJumpAcceptactPrintQueryactRefreshPreviewactReplaceQueryactToggleSortactShowPreviewactHidePreviewactTogglePreviewactTogglePreviewWrapactTogglePreviewWrapWordactTransformactTransformBorderLabelactTransformGhostactTransformHeaderactTransformHeaderLinesactTransformFooteractTransformHeaderLabelactTransformFooterLabelactTransformInputLabelactTransformListLabelactTransformNthactTransformWithNthactTransformPointeractTransformPreviewLabelactTransformPromptactTransformQueryactTransformSearchactTriggeractBgTransformactBgTransformBorderLabelactBgTransformGhostactBgTransformHeaderactBgTransformHeaderLinesactBgTransformFooteractBgTransformHeaderLabelactBgTransformFooterLabelactBgTransformInputLabelactBgTransformListLabelactBgTransformNthactBgTransformWithNthactBgTransformPointeractBgTransformPreviewLabelactBgTransformPromptactBgTransformQueryactBgTransformSearchactBgCancelactSearchactPreviewactPreviewTopactPreviewBottomactPreviewUpactPreviewDownactPreviewPageUpactPreviewPageDownactPreviewHalfPageUpactPreviewHalfPageDownactPrevHistoryactPrevSelectedactPrintactPutactNextHistoryactNextSelectedactExecuteactExecuteSilentactExecuteMultiactSigStopactBestactFirstactLastactReloadactReloadSyncactDisableSearchactEnableSearchactSelectactDeselectactUnbindactRebindactToggleBindactBecomeactShowHeaderactHideHeaderactBellactExcludeactExcludeMultiactAsync"
 
-var _actionType_index = [...]uint16{0, 9, 17, 25, 35, 57, 77, 84, 92, 110, 118, 127, 144, 165, 180, 201, 225, 240, 258, 267, 287, 301, 316, 331, 351, 371, 390, 408, 422, 434, 450, 466, 487, 509, 524, 538, 552, 565, 582, 590, 603, 619, 631, 639, 653, 667, 684, 695, 706, 720, 738, 755, 762, 781, 803, 815, 829, 838, 853, 865, 878, 889, 900, 912, 926, 947, 962, 975, 992, 1010, 1026, 1038, 1050, 1063, 1078, 1092, 1104, 1116, 1133, 1140, 1152, 1157, 1167, 1176, 1187, 1198, 1211, 1226, 1237, 1250, 1265, 1272, 1285, 1298, 1315, 1330, 1343, 1357, 1371, 1387, 1407, 1431, 1443, 1466, 1483, 1501, 1519, 1542, 1565, 1587, 1608, 1623, 1642, 1666, 1684, 1701, 1719, 1729, 1743, 1768, 1787, 1807, 1827, 1852, 1877, 1901, 1924, 1941, 1962, 1988, 2008, 2027, 2047, 2058, 2067, 2077, 2090, 2106, 2118, 2132, 2148, 2166, 2186, 2208, 2222, 2237, 2245, 2251, 2265, 2280, 2290, 2306, 2321, 2331, 2338, 2346, 2353, 2362, 2375, 2391, 2406, 2415, 2426, 2435, 2444, 2457, 2466, 2479, 2492, 2499, 2509, 2524, 2532}
+var _actionType_index = [...]uint16{0, 9, 17, 25, 35, 57, 77, 84, 92, 110, 118, 127, 144, 165, 180, 201, 225, 240, 258, 267, 287, 301, 316, 336, 351, 371, 391, 410, 428, 442, 454, 470, 486, 502, 523, 545, 560, 574, 588, 601, 618, 626, 639, 655, 667, 675, 689, 703, 720, 731, 742, 756, 774, 791, 798, 817, 839, 851, 865, 874, 889, 901, 914, 925, 936, 948, 962, 983, 998, 1011, 1028, 1046, 1062, 1074, 1086, 1099, 1114, 1128, 1140, 1152, 1169, 1176, 1188, 1193, 1203, 1212, 1223, 1234, 1247, 1262, 1273, 1286, 1301, 1308, 1321, 1334, 1351, 1366, 1379, 1393, 1407, 1423, 1443, 1467, 1479, 1502, 1519, 1537, 1560, 1578, 1601, 1624, 1646, 1667, 1682, 1701, 1720, 1744, 1762, 1779, 1797, 1807, 1821, 1846, 1865, 1885, 1910, 1930, 1955, 1980, 2004, 2027, 2044, 2065, 2086, 2112, 2132, 2151, 2171, 2182, 2191, 2201, 2214, 2230, 2242, 2256, 2272, 2290, 2310, 2332, 2346, 2361, 2369, 2375, 2389, 2404, 2414, 2430, 2445, 2455, 2462, 2470, 2477, 2486, 2499, 2515, 2530, 2539, 2550, 2559, 2568, 2581, 2590, 2603, 2616, 2623, 2633, 2648, 2656}
 
 func (i actionType) String() string {
 	if i < 0 || i >= actionType(len(_actionType_index)-1) {

src/algo/SIMD.md

@@ -0,0 +1,99 @@
+# SIMD byte search: `indexByteTwo` / `lastIndexByteTwo`
+
+## What these functions do
+
+`indexByteTwo(s []byte, b1, b2 byte) int` — returns the index of the
+**first** occurrence of `b1` or `b2` in `s`, or `-1`.
+
+`lastIndexByteTwo(s []byte, b1, b2 byte) int` — returns the index of the
+**last** occurrence of `b1` or `b2` in `s`, or `-1`.
+
+They are used by the fuzzy matching algorithm (`algo.go`) to skip ahead
+during case-insensitive search. Instead of calling `bytes.IndexByte` twice
+(once for lowercase, once for uppercase), a single SIMD pass finds both at
+once.
+
+## File layout
+
+| File                  | Purpose                                                           |
+| ------                | ---------                                                         |
+| `indexbyte2_arm64.go` | Go declarations (`//go:noescape`) for ARM64                       |
+| `indexbyte2_arm64.s`  | ARM64 NEON assembly (32-byte aligned blocks, syndrome extraction) |
+| `indexbyte2_amd64.go` | Go declarations + AVX2 runtime detection for AMD64                |
+| `indexbyte2_amd64.s`  | AMD64 AVX2/SSE2 assembly with CPUID dispatch                      |
+| `indexbyte2_other.go` | Pure Go fallback for all other architectures                      |
+| `indexbyte2_test.go`  | Unit tests, exhaustive tests, fuzz tests, and benchmarks          |
+
+## How the SIMD implementations work
+
+**ARM64 (NEON):**
+- Broadcasts both needle bytes into NEON registers (`VMOV`).
+- Processes 32-byte aligned chunks. For each chunk, compares all bytes
+  against both needles (`VCMEQ`), ORs the results (`VORR`), and builds a
+  64-bit syndrome with 2 bits per byte.
+- `indexByteTwo` uses `RBIT` + `CLZ` to find the lowest set bit (first match).
+- `lastIndexByteTwo` scans backward and uses `CLZ` on the raw syndrome to
+  find the highest set bit (last match).
+- Handles alignment and partial first/last blocks with bit masking.
+- Adapted from Go's `internal/bytealg/indexbyte_arm64.s`.
+
+**AMD64 (AVX2 with SSE2 fallback):**
+- At init time, `cpuHasAVX2()` checks CPUID + XGETBV for AVX2 and OS YMM
+  support. The result is cached in `_useAVX2`.
+- **AVX2 path** (inputs >= 32 bytes, when available):
+  - Broadcasts both needles via `VPBROADCASTB`.
+  - Processes 32-byte blocks: `VPCMPEQB` against both needles, `VPOR`, then
+    `VPMOVMSKB` to get a 32-bit mask.
+  - 5 instructions per loop iteration (vs 7 for SSE2) at 2x the throughput.
+  - `VZEROUPPER` before every return to avoid SSE/AVX transition penalties.
+- **SSE2 fallback** (inputs < 32 bytes, or CPUs without AVX2):
+  - Broadcasts via `PUNPCKLBW` + `PSHUFL`.
+  - Processes 16-byte blocks: `PCMPEQB`, `POR`, `PMOVMSKB`.
+  - Small inputs (<16 bytes) are handled with page-boundary-safe loads.
+- Both paths use `BSFL` (forward) / `BSRL` (reverse) for bit scanning.
+- Adapted from Go's `internal/bytealg/indexbyte_amd64.s`.
+
+**Fallback (other platforms):**
+- `indexByteTwo` uses two `bytes.IndexByte` calls with scope-limiting
+  (search `b1` first, then limit the `b2` search to `s[:i1]`).
+- `lastIndexByteTwo` uses a simple backward for loop.
+
+## Running tests
+
+```bash
+# Unit + exhaustive tests
+go test ./src/algo/ -run 'TestIndexByteTwo|TestLastIndexByteTwo' -v
+
+# Fuzz tests (run for 10 seconds each)
+go test ./src/algo/ -run '^$' -fuzz FuzzIndexByteTwo -fuzztime 10s
+go test ./src/algo/ -run '^$' -fuzz FuzzLastIndexByteTwo -fuzztime 10s
+
+# Cross-architecture: test amd64 on an arm64 Mac (via Rosetta)
+GOARCH=amd64 go test ./src/algo/ -run 'TestIndexByteTwo|TestLastIndexByteTwo' -v
+GOARCH=amd64 go test ./src/algo/ -run '^$' -fuzz FuzzIndexByteTwo -fuzztime 10s
+GOARCH=amd64 go test ./src/algo/ -run '^$' -fuzz FuzzLastIndexByteTwo -fuzztime 10s
+```
+
+## Running micro-benchmarks
+
+```bash
+# All indexByteTwo / lastIndexByteTwo benchmarks
+go test ./src/algo/ -bench 'IndexByteTwo' -benchmem
+
+# Specific size
+go test ./src/algo/ -bench 'IndexByteTwo_1000'
+```
+
+Each benchmark compares the SIMD `asm` implementation against reference
+implementations (`2xIndexByte` using `bytes.IndexByte`, and a simple `loop`).
+
+## Correctness verification
+
+The assembly is verified by three layers of testing:
+
+1. **Table-driven tests** — known inputs with expected outputs.
+2. **Exhaustive tests** — all lengths 0–256, every match position, no-match
+   cases, and both-bytes-present cases, compared against a simple loop
+   reference.
+3. **Fuzz tests** — randomized inputs via `testing.F`, compared against the
+   same loop reference.

src/algo/algo.go

@@ -321,22 +321,15 @@ type Algo func(caseSensitive bool, normalize bool, forward bool, input *util.Cha
 
 func trySkip(input *util.Chars, caseSensitive bool, b byte, from int) int {
 	byteArray := input.Bytes()[from:]
-	idx := bytes.IndexByte(byteArray, b)
-	if idx == 0 {
-		// Can't skip any further
-		return from
-	}
-	// We may need to search for the uppercase letter again. We don't have to
-	// consider normalization as we can be sure that this is an ASCII string.
+	// For case-insensitive search of a letter, search for both cases in one pass
 	if !caseSensitive && b >= 'a' && b <= 'z' {
-		if idx > 0 {
-			byteArray = byteArray[:idx]
-		}
-		uidx := bytes.IndexByte(byteArray, b-32)
-		if uidx >= 0 {
-			idx = uidx
+		idx := IndexByteTwo(byteArray, b, b-32)
+		if idx < 0 {
+			return -1
 		}
+		return from + idx
 	}
+	idx := bytes.IndexByte(byteArray, b)
 	if idx < 0 {
 		return -1
 	}
@@ -380,14 +373,17 @@ func asciiFuzzyIndex(input *util.Chars, pattern []rune, caseSensitive bool) (int
 	}
 
 	// Find the last appearance of the last character of the pattern to limit the search scope
-	bu := b
-	if !caseSensitive && b >= 'a' && b <= 'z' {
-		bu = b - 32
-	}
 	scope := input.Bytes()[lastIdx:]
-	for offset := len(scope) - 1; offset > 0; offset-- {
-		if scope[offset] == b || scope[offset] == bu {
-			return firstIdx, lastIdx + offset + 1
+	if len(scope) > 1 {
+		tail := scope[1:]
+		var end int
+		if !caseSensitive && b >= 'a' && b <= 'z' {
+			end = lastIndexByteTwo(tail, b, b-32)
+		} else {
+			end = bytes.LastIndexByte(tail, b)
+		}
+		if end >= 0 {
+			return firstIdx, lastIdx + 1 + end + 1
 		}
 	}
 	return firstIdx, lastIdx + 1

src/algo/indexbyte2_amd64.go

@@ -0,0 +1,24 @@
+//go:build amd64
+
+package algo
+
+var _useAVX2 bool
+
+func init() {
+	_useAVX2 = cpuHasAVX2()
+}
+
+//go:noescape
+func cpuHasAVX2() bool
+
+// indexByteTwo returns the index of the first occurrence of b1 or b2 in s,
+// or -1 if neither is present. Uses AVX2 when available, SSE2 otherwise.
+//
+//go:noescape
+func IndexByteTwo(s []byte, b1, b2 byte) int
+
+// lastIndexByteTwo returns the index of the last occurrence of b1 or b2 in s,
+// or -1 if neither is present. Uses AVX2 when available, SSE2 otherwise.
+//
+//go:noescape
+func lastIndexByteTwo(s []byte, b1, b2 byte) int

src/algo/indexbyte2_amd64.s

@@ -0,0 +1,377 @@
+#include "textflag.h"
+
+// func cpuHasAVX2() bool
+//
+// Checks CPUID and XGETBV for AVX2 + OS YMM support.
+TEXT ·cpuHasAVX2(SB),NOSPLIT,$0-1
+	MOVQ	BX, R8          // save BX (callee-saved, clobbered by CPUID)
+
+	// Check max CPUID leaf >= 7
+	MOVL	$0, AX
+	CPUID
+	CMPL	AX, $7
+	JL	cpuid_no
+
+	// Check OSXSAVE (CPUID.1:ECX bit 27)
+	MOVL	$1, AX
+	CPUID
+	TESTL	$(1<<27), CX
+	JZ	cpuid_no
+
+	// Check AVX2 (CPUID.7.0:EBX bit 5)
+	MOVL	$7, AX
+	MOVL	$0, CX
+	CPUID
+	TESTL	$(1<<5), BX
+	JZ	cpuid_no
+
+	// Check OS YMM state support via XGETBV
+	MOVL	$0, CX
+	BYTE	$0x0F; BYTE $0x01; BYTE $0xD0  // XGETBV → EDX:EAX
+	ANDL	$6, AX          // bits 1 (XMM) and 2 (YMM)
+	CMPL	AX, $6
+	JNE	cpuid_no
+
+	MOVQ	R8, BX          // restore BX
+	MOVB	$1, ret+0(FP)
+	RET
+
+cpuid_no:
+	MOVQ	R8, BX
+	MOVB	$0, ret+0(FP)
+	RET
+
+// func IndexByteTwo(s []byte, b1, b2 byte) int
+//
+// Returns the index of the first occurrence of b1 or b2 in s, or -1.
+// Uses AVX2 (32 bytes/iter) when available, SSE2 (16 bytes/iter) otherwise.
+TEXT ·IndexByteTwo(SB),NOSPLIT,$0-40
+	MOVQ	s_base+0(FP), SI
+	MOVQ	s_len+8(FP), BX
+	MOVBLZX	b1+24(FP), AX
+	MOVBLZX	b2+25(FP), CX
+	LEAQ	ret+32(FP), R8
+
+	TESTQ	BX, BX
+	JEQ	fwd_failure
+
+	// Try AVX2 for inputs >= 32 bytes
+	CMPQ	BX, $32
+	JLT	fwd_sse2
+	CMPB	·_useAVX2(SB), $1
+	JNE	fwd_sse2
+
+	// ====== AVX2 forward search ======
+	MOVD	AX, X0
+	VPBROADCASTB	X0, Y0       // Y0 = splat(b1)
+	MOVD	CX, X1
+	VPBROADCASTB	X1, Y1       // Y1 = splat(b2)
+
+	MOVQ	SI, DI
+	LEAQ	-32(SI)(BX*1), AX    // AX = last valid 32-byte chunk
+	JMP	fwd_avx2_entry
+
+fwd_avx2_loop:
+	VMOVDQU	(DI), Y2
+	VPCMPEQB	Y0, Y2, Y3
+	VPCMPEQB	Y1, Y2, Y4
+	VPOR	Y3, Y4, Y3
+	VPMOVMSKB	Y3, DX
+	BSFL	DX, DX
+	JNZ	fwd_avx2_success
+	ADDQ	$32, DI
+
+fwd_avx2_entry:
+	CMPQ	DI, AX
+	JB	fwd_avx2_loop
+
+	// Last 32-byte chunk (may overlap with previous)
+	MOVQ	AX, DI
+	VMOVDQU	(AX), Y2
+	VPCMPEQB	Y0, Y2, Y3
+	VPCMPEQB	Y1, Y2, Y4
+	VPOR	Y3, Y4, Y3
+	VPMOVMSKB	Y3, DX
+	BSFL	DX, DX
+	JNZ	fwd_avx2_success
+
+	MOVQ	$-1, (R8)
+	VZEROUPPER
+	RET
+
+fwd_avx2_success:
+	SUBQ	SI, DI
+	ADDQ	DX, DI
+	MOVQ	DI, (R8)
+	VZEROUPPER
+	RET
+
+	// ====== SSE2 forward search (< 32 bytes or no AVX2) ======
+
+fwd_sse2:
+	// Broadcast b1 into X0
+	MOVD	AX, X0
+	PUNPCKLBW	X0, X0
+	PUNPCKLBW	X0, X0
+	PSHUFL	$0, X0, X0
+
+	// Broadcast b2 into X4
+	MOVD	CX, X4
+	PUNPCKLBW	X4, X4
+	PUNPCKLBW	X4, X4
+	PSHUFL	$0, X4, X4
+
+	CMPQ	BX, $16
+	JLT	fwd_small
+
+	MOVQ	SI, DI
+	LEAQ	-16(SI)(BX*1), AX
+	JMP	fwd_sseloopentry
+
+fwd_sseloop:
+	MOVOU	(DI), X1
+	MOVOU	X1, X2
+	PCMPEQB	X0, X1
+	PCMPEQB	X4, X2
+	POR	X2, X1
+	PMOVMSKB	X1, DX
+	BSFL	DX, DX
+	JNZ	fwd_ssesuccess
+	ADDQ	$16, DI
+
+fwd_sseloopentry:
+	CMPQ	DI, AX
+	JB	fwd_sseloop
+
+	// Search the last 16-byte chunk (may overlap)
+	MOVQ	AX, DI
+	MOVOU	(AX), X1
+	MOVOU	X1, X2
+	PCMPEQB	X0, X1
+	PCMPEQB	X4, X2
+	POR	X2, X1
+	PMOVMSKB	X1, DX
+	BSFL	DX, DX
+	JNZ	fwd_ssesuccess
+
+fwd_failure:
+	MOVQ	$-1, (R8)
+	RET
+
+fwd_ssesuccess:
+	SUBQ	SI, DI
+	ADDQ	DX, DI
+	MOVQ	DI, (R8)
+	RET
+
+fwd_small:
+	// Check if loading 16 bytes from SI would cross a page boundary
+	LEAQ	16(SI), AX
+	TESTW	$0xff0, AX
+	JEQ	fwd_endofpage
+
+	MOVOU	(SI), X1
+	MOVOU	X1, X2
+	PCMPEQB	X0, X1
+	PCMPEQB	X4, X2
+	POR	X2, X1
+	PMOVMSKB	X1, DX
+	BSFL	DX, DX
+	JZ	fwd_failure
+	CMPL	DX, BX
+	JAE	fwd_failure
+	MOVQ	DX, (R8)
+	RET
+
+fwd_endofpage:
+	MOVOU	-16(SI)(BX*1), X1
+	MOVOU	X1, X2
+	PCMPEQB	X0, X1
+	PCMPEQB	X4, X2
+	POR	X2, X1
+	PMOVMSKB	X1, DX
+	MOVL	BX, CX
+	SHLL	CX, DX
+	SHRL	$16, DX
+	BSFL	DX, DX
+	JZ	fwd_failure
+	MOVQ	DX, (R8)
+	RET
+
+// func lastIndexByteTwo(s []byte, b1, b2 byte) int
+//
+// Returns the index of the last occurrence of b1 or b2 in s, or -1.
+// Uses AVX2 (32 bytes/iter) when available, SSE2 (16 bytes/iter) otherwise.
+TEXT ·lastIndexByteTwo(SB),NOSPLIT,$0-40
+	MOVQ	s_base+0(FP), SI
+	MOVQ	s_len+8(FP), BX
+	MOVBLZX	b1+24(FP), AX
+	MOVBLZX	b2+25(FP), CX
+	LEAQ	ret+32(FP), R8
+
+	TESTQ	BX, BX
+	JEQ	back_failure
+
+	// Try AVX2 for inputs >= 32 bytes
+	CMPQ	BX, $32
+	JLT	back_sse2
+	CMPB	·_useAVX2(SB), $1
+	JNE	back_sse2
+
+	// ====== AVX2 backward search ======
+	MOVD	AX, X0
+	VPBROADCASTB	X0, Y0
+	MOVD	CX, X1
+	VPBROADCASTB	X1, Y1
+
+	// DI = start of last 32-byte chunk
+	LEAQ	-32(SI)(BX*1), DI
+
+back_avx2_loop:
+	CMPQ	DI, SI
+	JBE	back_avx2_first
+
+	VMOVDQU	(DI), Y2
+	VPCMPEQB	Y0, Y2, Y3
+	VPCMPEQB	Y1, Y2, Y4
+	VPOR	Y3, Y4, Y3
+	VPMOVMSKB	Y3, DX
+	BSRL	DX, DX
+	JNZ	back_avx2_success
+	SUBQ	$32, DI
+	JMP	back_avx2_loop
+
+back_avx2_first:
+	// First 32 bytes (DI <= SI, load from SI)
+	VMOVDQU	(SI), Y2
+	VPCMPEQB	Y0, Y2, Y3
+	VPCMPEQB	Y1, Y2, Y4
+	VPOR	Y3, Y4, Y3
+	VPMOVMSKB	Y3, DX
+	BSRL	DX, DX
+	JNZ	back_avx2_firstsuccess
+
+	MOVQ	$-1, (R8)
+	VZEROUPPER
+	RET
+
+back_avx2_success:
+	SUBQ	SI, DI
+	ADDQ	DX, DI
+	MOVQ	DI, (R8)
+	VZEROUPPER
+	RET
+
+back_avx2_firstsuccess:
+	MOVQ	DX, (R8)
+	VZEROUPPER
+	RET
+
+	// ====== SSE2 backward search (< 32 bytes or no AVX2) ======
+
+back_sse2:
+	// Broadcast b1 into X0
+	MOVD	AX, X0
+	PUNPCKLBW	X0, X0
+	PUNPCKLBW	X0, X0
+	PSHUFL	$0, X0, X0
+
+	// Broadcast b2 into X4
+	MOVD	CX, X4
+	PUNPCKLBW	X4, X4
+	PUNPCKLBW	X4, X4
+	PSHUFL	$0, X4, X4
+
+	CMPQ	BX, $16
+	JLT	back_small
+
+	// DI = start of last 16-byte chunk
+	LEAQ	-16(SI)(BX*1), DI
+
+back_sseloop:
+	CMPQ	DI, SI
+	JBE	back_ssefirst
+
+	MOVOU	(DI), X1
+	MOVOU	X1, X2
+	PCMPEQB	X0, X1
+	PCMPEQB	X4, X2
+	POR	X2, X1
+	PMOVMSKB	X1, DX
+	BSRL	DX, DX
+	JNZ	back_ssesuccess
+	SUBQ	$16, DI
+	JMP	back_sseloop
+
+back_ssefirst:
+	// First 16 bytes (DI <= SI, load from SI)
+	MOVOU	(SI), X1
+	MOVOU	X1, X2
+	PCMPEQB	X0, X1
+	PCMPEQB	X4, X2
+	POR	X2, X1
+	PMOVMSKB	X1, DX
+	BSRL	DX, DX
+	JNZ	back_ssefirstsuccess
+
+back_failure:
+	MOVQ	$-1, (R8)
+	RET
+
+back_ssesuccess:
+	SUBQ	SI, DI
+	ADDQ	DX, DI
+	MOVQ	DI, (R8)
+	RET
+
+back_ssefirstsuccess:
+	// DX = byte offset from base
+	MOVQ	DX, (R8)
+	RET
+
+back_small:
+	// Check page boundary
+	LEAQ	16(SI), AX
+	TESTW	$0xff0, AX
+	JEQ	back_endofpage
+
+	MOVOU	(SI), X1
+	MOVOU	X1, X2
+	PCMPEQB	X0, X1
+	PCMPEQB	X4, X2
+	POR	X2, X1
+	PMOVMSKB	X1, DX
+	// Mask to first BX bytes: keep bits 0..BX-1
+	MOVL	$1, AX
+	MOVL	BX, CX
+	SHLL	CX, AX
+	DECL	AX
+	ANDL	AX, DX
+	BSRL	DX, DX
+	JZ	back_failure
+	MOVQ	DX, (R8)
+	RET
+
+back_endofpage:
+	// Load 16 bytes ending at base+n
+	MOVOU	-16(SI)(BX*1), X1
+	MOVOU	X1, X2
+	PCMPEQB	X0, X1
+	PCMPEQB	X4, X2
+	POR	X2, X1
+	PMOVMSKB	X1, DX
+	// Bits correspond to bytes [base+n-16, base+n).
+	// We want original bytes [0, n), which are bits [16-n, 16).
+	// Mask: keep bits (16-n) through 15.
+	MOVL	$16, CX
+	SUBL	BX, CX
+	SHRL	CX, DX
+	SHLL	CX, DX
+	BSRL	DX, DX
+	JZ	back_failure
+	// DX is the bit position in the loaded chunk.
+	// Original byte index = DX - (16 - n) = DX + n - 16
+	ADDL	BX, DX
+	SUBL	$16, DX
+	MOVQ	DX, (R8)
+	RET

src/algo/indexbyte2_arm64.go

@@ -0,0 +1,17 @@
+//go:build arm64
+
+package algo
+
+// indexByteTwo returns the index of the first occurrence of b1 or b2 in s,
+// or -1 if neither is present. Implemented in assembly using ARM64 NEON
+// to search for both bytes in a single pass.
+//
+//go:noescape
+func IndexByteTwo(s []byte, b1, b2 byte) int
+
+// lastIndexByteTwo returns the index of the last occurrence of b1 or b2 in s,
+// or -1 if neither is present. Implemented in assembly using ARM64 NEON,
+// scanning backward.
+//
+//go:noescape
+func lastIndexByteTwo(s []byte, b1, b2 byte) int

src/algo/indexbyte2_arm64.s

@@ -0,0 +1,249 @@
+#include "textflag.h"
+
+// func IndexByteTwo(s []byte, b1, b2 byte) int
+//
+// Returns the index of the first occurrence of b1 or b2 in s, or -1.
+// Uses ARM64 NEON to search for both bytes in a single pass over the data.
+// Adapted from Go's internal/bytealg/indexbyte_arm64.s (single-byte version).
+TEXT ·IndexByteTwo(SB),NOSPLIT,$0-40
+	MOVD	s_base+0(FP), R0
+	MOVD	s_len+8(FP), R2
+	MOVBU	b1+24(FP), R1
+	MOVBU	b2+25(FP), R7
+	MOVD	$ret+32(FP), R8
+
+	// Core algorithm:
+	// For each 32-byte chunk we calculate a 64-bit syndrome value,
+	// with two bits per byte. We compare against both b1 and b2,
+	// OR the results, then use the same syndrome extraction as
+	// Go's IndexByte.
+
+	CBZ	R2, fail
+	MOVD	R0, R11
+	// Magic constant 0x40100401 allows us to identify which lane matches.
+	// Each byte in the group of 4 gets a distinct bit: 1, 4, 16, 64.
+	MOVD	$0x40100401, R5
+	VMOV	R1, V0.B16    // V0 = splat(b1)
+	VMOV	R7, V7.B16    // V7 = splat(b2)
+	// Work with aligned 32-byte chunks
+	BIC	$0x1f, R0, R3
+	VMOV	R5, V5.S4
+	ANDS	$0x1f, R0, R9
+	AND	$0x1f, R2, R10
+	BEQ	loop
+
+	// Input string is not 32-byte aligned. Process the first
+	// aligned 32-byte block and mask off bytes before our start.
+	VLD1.P	(R3), [V1.B16, V2.B16]
+	SUB	$0x20, R9, R4
+	ADDS	R4, R2, R2
+	// Compare against both needles
+	VCMEQ	V0.B16, V1.B16, V3.B16  // b1 vs first 16 bytes
+	VCMEQ	V7.B16, V1.B16, V8.B16  // b2 vs first 16 bytes
+	VORR	V8.B16, V3.B16, V3.B16  // combine
+	VCMEQ	V0.B16, V2.B16, V4.B16  // b1 vs second 16 bytes
+	VCMEQ	V7.B16, V2.B16, V9.B16  // b2 vs second 16 bytes
+	VORR	V9.B16, V4.B16, V4.B16  // combine
+	// Build syndrome
+	VAND	V5.B16, V3.B16, V3.B16
+	VAND	V5.B16, V4.B16, V4.B16
+	VADDP	V4.B16, V3.B16, V6.B16
+	VADDP	V6.B16, V6.B16, V6.B16
+	VMOV	V6.D[0], R6
+	// Clear the irrelevant lower bits
+	LSL	$1, R9, R4
+	LSR	R4, R6, R6
+	LSL	R4, R6, R6
+	// The first block can also be the last
+	BLS	masklast
+	// Have we found something already?
+	CBNZ	R6, tail
+
+loop:
+	VLD1.P	(R3), [V1.B16, V2.B16]
+	SUBS	$0x20, R2, R2
+	// Compare against both needles, OR results
+	VCMEQ	V0.B16, V1.B16, V3.B16
+	VCMEQ	V7.B16, V1.B16, V8.B16
+	VORR	V8.B16, V3.B16, V3.B16
+	VCMEQ	V0.B16, V2.B16, V4.B16
+	VCMEQ	V7.B16, V2.B16, V9.B16
+	VORR	V9.B16, V4.B16, V4.B16
+	// If we're out of data we finish regardless of the result
+	BLS	end
+	// Fast check: OR both halves and check for any match
+	VORR	V4.B16, V3.B16, V6.B16
+	VADDP	V6.D2, V6.D2, V6.D2
+	VMOV	V6.D[0], R6
+	CBZ	R6, loop
+
+end:
+	// Found something or out of data — build full syndrome
+	VAND	V5.B16, V3.B16, V3.B16
+	VAND	V5.B16, V4.B16, V4.B16
+	VADDP	V4.B16, V3.B16, V6.B16
+	VADDP	V6.B16, V6.B16, V6.B16
+	VMOV	V6.D[0], R6
+	// Only mask for the last block
+	BHS	tail
+
+masklast:
+	// Clear irrelevant upper bits
+	ADD	R9, R10, R4
+	AND	$0x1f, R4, R4
+	SUB	$0x20, R4, R4
+	NEG	R4<<1, R4
+	LSL	R4, R6, R6
+	LSR	R4, R6, R6
+
+tail:
+	CBZ	R6, fail
+	RBIT	R6, R6
+	SUB	$0x20, R3, R3
+	CLZ	R6, R6
+	ADD	R6>>1, R3, R0
+	SUB	R11, R0, R0
+	MOVD	R0, (R8)
+	RET
+
+fail:
+	MOVD	$-1, R0
+	MOVD	R0, (R8)
+	RET
+
+// func lastIndexByteTwo(s []byte, b1, b2 byte) int
+//
+// Returns the index of the last occurrence of b1 or b2 in s, or -1.
+// Scans backward using ARM64 NEON.
+TEXT ·lastIndexByteTwo(SB),NOSPLIT,$0-40
+	MOVD	s_base+0(FP), R0
+	MOVD	s_len+8(FP), R2
+	MOVBU	b1+24(FP), R1
+	MOVBU	b2+25(FP), R7
+	MOVD	$ret+32(FP), R8
+
+	CBZ	R2, lfail
+	MOVD	R0, R11          // save base
+	ADD	R0, R2, R12      // R12 = end = base + len
+	MOVD	$0x40100401, R5
+	VMOV	R1, V0.B16       // V0 = splat(b1)
+	VMOV	R7, V7.B16       // V7 = splat(b2)
+	VMOV	R5, V5.S4
+
+	// Align: find the aligned block containing the last byte
+	SUB	$1, R12, R3
+	BIC	$0x1f, R3, R3    // R3 = start of aligned block containing last byte
+
+	// --- Process tail block ---
+	VLD1	(R3), [V1.B16, V2.B16]
+	VCMEQ	V0.B16, V1.B16, V3.B16
+	VCMEQ	V7.B16, V1.B16, V8.B16
+	VORR	V8.B16, V3.B16, V3.B16
+	VCMEQ	V0.B16, V2.B16, V4.B16
+	VCMEQ	V7.B16, V2.B16, V9.B16
+	VORR	V9.B16, V4.B16, V4.B16
+	VAND	V5.B16, V3.B16, V3.B16
+	VAND	V5.B16, V4.B16, V4.B16
+	VADDP	V4.B16, V3.B16, V6.B16
+	VADDP	V6.B16, V6.B16, V6.B16
+	VMOV	V6.D[0], R6
+
+	// Mask upper bits (bytes past end of slice)
+	// tail_bytes = end - R3 (1..32)
+	SUB	R3, R12, R10     // R10 = tail_bytes
+	MOVD	$64, R4
+	SUB	R10<<1, R4, R4   // R4 = 64 - 2*tail_bytes
+	LSL	R4, R6, R6
+	LSR	R4, R6, R6
+
+	// Is this also the head block?
+	CMP	R11, R3          // R3 - R11
+	BLO	lmaskfirst       // R3 < base: head+tail in same block
+	BEQ	ltailonly         // R3 == base: single aligned block
+
+	// R3 > base: more blocks before this one
+	CBNZ	R6, llast
+	B	lbacksetup
+
+ltailonly:
+	// Single block, already masked upper bits
+	CBNZ	R6, llast
+	B	lfail
+
+lmaskfirst:
+	// Mask lower bits (bytes before start of slice)
+	SUB	R3, R11, R4      // R4 = base - R3
+	LSL	$1, R4, R4
+	LSR	R4, R6, R6
+	LSL	R4, R6, R6
+	CBNZ	R6, llast
+	B	lfail
+
+lbacksetup:
+	SUB	$0x20, R3
+
+lbackloop:
+	VLD1	(R3), [V1.B16, V2.B16]
+	VCMEQ	V0.B16, V1.B16, V3.B16
+	VCMEQ	V7.B16, V1.B16, V8.B16
+	VORR	V8.B16, V3.B16, V3.B16
+	VCMEQ	V0.B16, V2.B16, V4.B16
+	VCMEQ	V7.B16, V2.B16, V9.B16
+	VORR	V9.B16, V4.B16, V4.B16
+	// Quick check: any match in this block?
+	VORR	V4.B16, V3.B16, V6.B16
+	VADDP	V6.D2, V6.D2, V6.D2
+	VMOV	V6.D[0], R6
+
+	// Is this a head block? (R3 < base)
+	CMP	R11, R3
+	BLO	lheadblock
+
+	// Full block (R3 >= base)
+	CBNZ	R6, lbackfound
+	// More blocks?
+	BEQ	lfail            // R3 == base, no more
+	SUB	$0x20, R3
+	B	lbackloop
+
+lbackfound:
+	// Build full syndrome
+	VAND	V5.B16, V3.B16, V3.B16
+	VAND	V5.B16, V4.B16, V4.B16
+	VADDP	V4.B16, V3.B16, V6.B16
+	VADDP	V6.B16, V6.B16, V6.B16
+	VMOV	V6.D[0], R6
+	B	llast
+
+lheadblock:
+	// R3 < base. Build full syndrome if quick check had a match.
+	CBZ	R6, lfail
+	VAND	V5.B16, V3.B16, V3.B16
+	VAND	V5.B16, V4.B16, V4.B16
+	VADDP	V4.B16, V3.B16, V6.B16
+	VADDP	V6.B16, V6.B16, V6.B16
+	VMOV	V6.D[0], R6
+	// Mask lower bits
+	SUB	R3, R11, R4      // R4 = base - R3
+	LSL	$1, R4, R4
+	LSR	R4, R6, R6
+	LSL	R4, R6, R6
+	CBZ	R6, lfail
+
+llast:
+	// Find last match: highest set bit in syndrome
+	// Syndrome has bit 2i set for matching byte i.
+	// CLZ gives leading zeros; byte_offset = (63 - CLZ) / 2.
+	CLZ	R6, R6
+	MOVD	$63, R4
+	SUB	R6, R4, R6       // R6 = 63 - CLZ = bit position
+	LSR	$1, R6            // R6 = byte offset within block
+	ADD	R3, R6, R0        // R0 = absolute address
+	SUB	R11, R0, R0       // R0 = slice index
+	MOVD	R0, (R8)
+	RET
+
+lfail:
+	MOVD	$-1, R0
+	MOVD	R0, (R8)
+	RET

src/algo/indexbyte2_other.go

@@ -0,0 +1,33 @@
+//go:build !arm64 && !amd64
+
+package algo
+
+import "bytes"
+
+// indexByteTwo returns the index of the first occurrence of b1 or b2 in s,
+// or -1 if neither is present.
+func IndexByteTwo(s []byte, b1, b2 byte) int {
+	i1 := bytes.IndexByte(s, b1)
+	if i1 == 0 {
+		return 0
+	}
+	scope := s
+	if i1 > 0 {
+		scope = s[:i1]
+	}
+	if i2 := bytes.IndexByte(scope, b2); i2 >= 0 {
+		return i2
+	}
+	return i1
+}
+
+// lastIndexByteTwo returns the index of the last occurrence of b1 or b2 in s,
+// or -1 if neither is present.
+func lastIndexByteTwo(s []byte, b1, b2 byte) int {
+	for i := len(s) - 1; i >= 0; i-- {
+		if s[i] == b1 || s[i] == b2 {
+			return i
+		}
+	}
+	return -1
+}

src/algo/indexbyte2_test.go

@@ -0,0 +1,259 @@
+package algo
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestIndexByteTwo(t *testing.T) {
+	tests := []struct {
+		name string
+		s    string
+		b1   byte
+		b2   byte
+		want int
+	}{
+		{"empty", "", 'a', 'b', -1},
+		{"single_b1", "a", 'a', 'b', 0},
+		{"single_b2", "b", 'a', 'b', 0},
+		{"single_none", "c", 'a', 'b', -1},
+		{"b1_first", "xaxb", 'a', 'b', 1},
+		{"b2_first", "xbxa", 'a', 'b', 1},
+		{"same_byte", "xxa", 'a', 'a', 2},
+		{"at_end", "xxxxa", 'a', 'b', 4},
+		{"not_found", "xxxxxxxx", 'a', 'b', -1},
+		{"long_b1_at_3000", string(make([]byte, 3000)) + "a" + string(make([]byte, 1000)), 'a', 'b', 3000},
+		{"long_b2_at_3000", string(make([]byte, 3000)) + "b" + string(make([]byte, 1000)), 'a', 'b', 3000},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := IndexByteTwo([]byte(tt.s), tt.b1, tt.b2)
+			if got != tt.want {
+				t.Errorf("IndexByteTwo(%q, %c, %c) = %d, want %d", tt.s[:min(len(tt.s), 40)], tt.b1, tt.b2, got, tt.want)
+			}
+		})
+	}
+
+	// Exhaustive test: compare against loop reference for various lengths,
+	// including sizes around SIMD block boundaries (16, 32, 64).
+	for n := 0; n <= 256; n++ {
+		data := make([]byte, n)
+		for i := range data {
+			data[i] = byte('c' + (i % 20))
+		}
+		// Test with match at every position
+		for pos := 0; pos < n; pos++ {
+			for _, b := range []byte{'A', 'B'} {
+				data[pos] = b
+				got := IndexByteTwo(data, 'A', 'B')
+				want := loopIndexByteTwo(data, 'A', 'B')
+				if got != want {
+					t.Fatalf("IndexByteTwo(len=%d, match=%c@%d) = %d, want %d", n, b, pos, got, want)
+				}
+				data[pos] = byte('c' + (pos % 20))
+			}
+		}
+		// Test with no match
+		got := IndexByteTwo(data, 'A', 'B')
+		if got != -1 {
+			t.Fatalf("IndexByteTwo(len=%d, no match) = %d, want -1", n, got)
+		}
+		// Test with both bytes present
+		if n >= 2 {
+			data[n/3] = 'A'
+			data[n*2/3] = 'B'
+			got := IndexByteTwo(data, 'A', 'B')
+			want := loopIndexByteTwo(data, 'A', 'B')
+			if got != want {
+				t.Fatalf("IndexByteTwo(len=%d, both@%d,%d) = %d, want %d", n, n/3, n*2/3, got, want)
+			}
+			data[n/3] = byte('c' + ((n / 3) % 20))
+			data[n*2/3] = byte('c' + ((n * 2 / 3) % 20))
+		}
+	}
+}
+
+func TestLastIndexByteTwo(t *testing.T) {
+	tests := []struct {
+		name string
+		s    string
+		b1   byte
+		b2   byte
+		want int
+	}{
+		{"empty", "", 'a', 'b', -1},
+		{"single_b1", "a", 'a', 'b', 0},
+		{"single_b2", "b", 'a', 'b', 0},
+		{"single_none", "c", 'a', 'b', -1},
+		{"b1_last", "xbxa", 'a', 'b', 3},
+		{"b2_last", "xaxb", 'a', 'b', 3},
+		{"same_byte", "axx", 'a', 'a', 0},
+		{"at_start", "axxxx", 'a', 'b', 0},
+		{"both_present", "axbx", 'a', 'b', 2},
+		{"not_found", "xxxxxxxx", 'a', 'b', -1},
+		{"long_b1_at_3000", string(make([]byte, 3000)) + "a" + string(make([]byte, 1000)), 'a', 'b', 3000},
+		{"long_b2_at_end", string(make([]byte, 4000)) + "b", 'a', 'b', 4000},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := lastIndexByteTwo([]byte(tt.s), tt.b1, tt.b2)
+			if got != tt.want {
+				t.Errorf("lastIndexByteTwo(%q, %c, %c) = %d, want %d", tt.s[:min(len(tt.s), 40)], tt.b1, tt.b2, got, tt.want)
+			}
+		})
+	}
+
+	// Exhaustive test against loop reference
+	for n := 0; n <= 256; n++ {
+		data := make([]byte, n)
+		for i := range data {
+			data[i] = byte('c' + (i % 20))
+		}
+		for pos := 0; pos < n; pos++ {
+			for _, b := range []byte{'A', 'B'} {
+				data[pos] = b
+				got := lastIndexByteTwo(data, 'A', 'B')
+				want := refLastIndexByteTwo(data, 'A', 'B')
+				if got != want {
+					t.Fatalf("lastIndexByteTwo(len=%d, match=%c@%d) = %d, want %d", n, b, pos, got, want)
+				}
+				data[pos] = byte('c' + (pos % 20))
+			}
+		}
+		// No match
+		got := lastIndexByteTwo(data, 'A', 'B')
+		if got != -1 {
+			t.Fatalf("lastIndexByteTwo(len=%d, no match) = %d, want -1", n, got)
+		}
+		// Both bytes present
+		if n >= 2 {
+			data[n/3] = 'A'
+			data[n*2/3] = 'B'
+			got := lastIndexByteTwo(data, 'A', 'B')
+			want := refLastIndexByteTwo(data, 'A', 'B')
+			if got != want {
+				t.Fatalf("lastIndexByteTwo(len=%d, both@%d,%d) = %d, want %d", n, n/3, n*2/3, got, want)
+			}
+			data[n/3] = byte('c' + ((n / 3) % 20))
+			data[n*2/3] = byte('c' + ((n * 2 / 3) % 20))
+		}
+	}
+}
+
+func FuzzIndexByteTwo(f *testing.F) {
+	f.Add([]byte("hello world"), byte('o'), byte('l'))
+	f.Add([]byte(""), byte('a'), byte('b'))
+	f.Add([]byte("aaa"), byte('a'), byte('a'))
+	f.Fuzz(func(t *testing.T, data []byte, b1, b2 byte) {
+		got := IndexByteTwo(data, b1, b2)
+		want := loopIndexByteTwo(data, b1, b2)
+		if got != want {
+			t.Errorf("IndexByteTwo(len=%d, b1=%d, b2=%d) = %d, want %d", len(data), b1, b2, got, want)
+		}
+	})
+}
+
+func FuzzLastIndexByteTwo(f *testing.F) {
+	f.Add([]byte("hello world"), byte('o'), byte('l'))
+	f.Add([]byte(""), byte('a'), byte('b'))
+	f.Add([]byte("aaa"), byte('a'), byte('a'))
+	f.Fuzz(func(t *testing.T, data []byte, b1, b2 byte) {
+		got := lastIndexByteTwo(data, b1, b2)
+		want := refLastIndexByteTwo(data, b1, b2)
+		if got != want {
+			t.Errorf("lastIndexByteTwo(len=%d, b1=%d, b2=%d) = %d, want %d", len(data), b1, b2, got, want)
+		}
+	})
+}
+
+// Reference implementations for correctness checking
+func refIndexByteTwo(s []byte, b1, b2 byte) int {
+	i1 := bytes.IndexByte(s, b1)
+	if i1 == 0 {
+		return 0
+	}
+	scope := s
+	if i1 > 0 {
+		scope = s[:i1]
+	}
+	if i2 := bytes.IndexByte(scope, b2); i2 >= 0 {
+		return i2
+	}
+	return i1
+}
+
+func loopIndexByteTwo(s []byte, b1, b2 byte) int {
+	for i, b := range s {
+		if b == b1 || b == b2 {
+			return i
+		}
+	}
+	return -1
+}
+
+func refLastIndexByteTwo(s []byte, b1, b2 byte) int {
+	for i := len(s) - 1; i >= 0; i-- {
+		if s[i] == b1 || s[i] == b2 {
+			return i
+		}
+	}
+	return -1
+}
+
+func benchIndexByteTwo(b *testing.B, size int, pos int) {
+	data := make([]byte, size)
+	for i := range data {
+		data[i] = byte('a' + (i % 20))
+	}
+	data[pos] = 'Z'
+
+	type impl struct {
+		name string
+		fn   func([]byte, byte, byte) int
+	}
+	impls := []impl{
+		{"asm", IndexByteTwo},
+		{"2xIndexByte", refIndexByteTwo},
+		{"loop", loopIndexByteTwo},
+	}
+	for _, im := range impls {
+		b.Run(im.name, func(b *testing.B) {
+			for i := 0; i < b.N; i++ {
+				im.fn(data, 'Z', 'z')
+			}
+		})
+	}
+}
+
+func benchLastIndexByteTwo(b *testing.B, size int, pos int) {
+	data := make([]byte, size)
+	for i := range data {
+		data[i] = byte('a' + (i % 20))
+	}
+	data[pos] = 'Z'
+
+	type impl struct {
+		name string
+		fn   func([]byte, byte, byte) int
+	}
+	impls := []impl{
+		{"asm", lastIndexByteTwo},
+		{"loop", refLastIndexByteTwo},
+	}
+	for _, im := range impls {
+		b.Run(im.name, func(b *testing.B) {
+			for i := 0; i < b.N; i++ {
+				im.fn(data, 'Z', 'z')
+			}
+		})
+	}
+}
+
+func BenchmarkIndexByteTwo_10(b *testing.B)       { benchIndexByteTwo(b, 10, 8) }
+func BenchmarkIndexByteTwo_100(b *testing.B)      { benchIndexByteTwo(b, 100, 80) }
+func BenchmarkIndexByteTwo_1000(b *testing.B)     { benchIndexByteTwo(b, 1000, 800) }
+func BenchmarkLastIndexByteTwo_10(b *testing.B)   { benchLastIndexByteTwo(b, 10, 2) }
+func BenchmarkLastIndexByteTwo_100(b *testing.B)  { benchLastIndexByteTwo(b, 100, 20) }
+func BenchmarkLastIndexByteTwo_1000(b *testing.B) { benchLastIndexByteTwo(b, 1000, 200) }

src/ansi.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 	"unicode/utf8"
 
+	"github.com/junegunn/fzf/src/algo"
 	"github.com/junegunn/fzf/src/tui"
 )
 
@@ -123,31 +124,31 @@ func toAnsiString(color tui.Color, offset int) string {
 	return ret + ";"
 }
 
-func isPrint(c uint8) bool {
-	return '\x20' <= c && c <= '\x7e'
-}
-
 func matchOperatingSystemCommand(s string, start int) int {
 	// `\x1b][0-9][;:][[:print:]]+(?:\x1b\\\\|\x07)`
 	//                 ^ match starting here after the first printable character
 	//
 	i := start // prefix matched in nextAnsiEscapeSequence()
-	for ; i < len(s) && isPrint(s[i]); i++ {
+
+	// Find the terminator: BEL (\x07) or ESC (\x1b) for ST (\x1b\\)
+	idx := algo.IndexByteTwo(stringBytes(s[i:]), '\x07', '\x1b')
+	if idx < 0 {
+		return -1
 	}
-	if i < len(s) {
-		if s[i] == '\x07' {
-			return i + 1
-		}
-		// `\x1b]8;PARAMS;URI\x1b\\TITLE\x1b]8;;\x1b`
-		//                   ------
-		if s[i] == '\x1b' && i < len(s)-1 && s[i+1] == '\\' {
-			return i + 2
-		}
+	i += idx
+
+	if s[i] == '\x07' {
+		return i + 1
+	}
+	// `\x1b]8;PARAMS;URI\x1b\\TITLE\x1b]8;;\x1b`
+	//                   ------
+	if i < len(s)-1 && s[i+1] == '\\' {
+		return i + 2
 	}
 
 	// `\x1b]8;PARAMS;URI\x1b\\TITLE\x1b]8;;\x1b`
 	//                              ------------
-	if i < len(s) && s[:i+1] == "\x1b]8;;\x1b" {
+	if s[:i+1] == "\x1b]8;;\x1b" {
 		return i + 1
 	}
 
@@ -233,7 +234,7 @@ Loop:
 
 				// \x1b][0-9]+[;:][[:print:]]+(?:\x1b\\\\|\x07)
 				//            ---------------
-				if j > 2 && i+j+1 < len(s) && (s[i+j] == ';' || s[i+j] == ':') && isPrint(s[i+j+1]) {
+				if j > 2 && i+j+1 < len(s) && (s[i+j] == ';' || s[i+j] == ':') && s[i+j+1] >= '\x20' {
 					if k := matchOperatingSystemCommand(s[i:], j+2); k != -1 {
 						return i, i + k
 					}

src/cache.go

@@ -2,10 +2,13 @@ package fzf
 
 import "sync"
 
-// queryCache associates strings to lists of items
-type queryCache map[string][]Result
+// ChunkBitmap is a bitmap with one bit per item in a chunk.
+type ChunkBitmap [chunkBitWords]uint64
 
-// ChunkCache associates Chunk and query string to lists of items
+// queryCache associates query strings to bitmaps of matching items
+type queryCache map[string]ChunkBitmap
+
+// ChunkCache associates Chunk and query string to bitmaps
 type ChunkCache struct {
 	mutex sync.Mutex
 	cache map[*Chunk]*queryCache
@@ -30,9 +33,9 @@ func (cc *ChunkCache) retire(chunk ...*Chunk) {
 	cc.mutex.Unlock()
 }
 
-// Add adds the list to the cache
-func (cc *ChunkCache) Add(chunk *Chunk, key string, list []Result) {
-	if len(key) == 0 || !chunk.IsFull() || len(list) > queryCacheMax {
+// Add stores the bitmap for the given chunk and key
+func (cc *ChunkCache) Add(chunk *Chunk, key string, bitmap ChunkBitmap, matchCount int) {
+	if len(key) == 0 || !chunk.IsFull() || matchCount > queryCacheMax {
 		return
 	}
 
@@ -44,11 +47,11 @@ func (cc *ChunkCache) Add(chunk *Chunk, key string, list []Result) {
 		cc.cache[chunk] = &queryCache{}
 		qc = cc.cache[chunk]
 	}
-	(*qc)[key] = list
+	(*qc)[key] = bitmap
 }
 
-// Lookup is called to lookup ChunkCache
-func (cc *ChunkCache) Lookup(chunk *Chunk, key string) []Result {
+// Lookup returns the bitmap for the exact key
+func (cc *ChunkCache) Lookup(chunk *Chunk, key string) *ChunkBitmap {
 	if len(key) == 0 || !chunk.IsFull() {
 		return nil
 	}
@@ -58,15 +61,15 @@ func (cc *ChunkCache) Lookup(chunk *Chunk, key string) []Result {
 
 	qc, ok := cc.cache[chunk]
 	if ok {
-		list, ok := (*qc)[key]
-		if ok {
-			return list
+		if bm, ok := (*qc)[key]; ok {
+			return &bm
 		}
 	}
 	return nil
 }
 
-func (cc *ChunkCache) Search(chunk *Chunk, key string) []Result {
+// Search finds the bitmap for the longest prefix or suffix of the key
+func (cc *ChunkCache) Search(chunk *Chunk, key string) *ChunkBitmap {
 	if len(key) == 0 || !chunk.IsFull() {
 		return nil
 	}
@@ -86,8 +89,8 @@ func (cc *ChunkCache) Search(chunk *Chunk, key string) []Result {
 		prefix := key[:len(key)-idx]
 		suffix := key[idx:]
 		for _, substr := range [2]string{prefix, suffix} {
-			if cached, found := (*qc)[substr]; found {
-				return cached
+			if bm, found := (*qc)[substr]; found {
+				return &bm
 			}
 		}
 	}

src/cache_test.go

@@ -6,34 +6,34 @@ func TestChunkCache(t *testing.T) {
 	cache := NewChunkCache()
 	chunk1p := &Chunk{}
 	chunk2p := &Chunk{count: chunkSize}
-	items1 := []Result{{}}
-	items2 := []Result{{}, {}}
-	cache.Add(chunk1p, "foo", items1)
-	cache.Add(chunk2p, "foo", items1)
-	cache.Add(chunk2p, "bar", items2)
+	bm1 := ChunkBitmap{1}
+	bm2 := ChunkBitmap{1, 2}
+	cache.Add(chunk1p, "foo", bm1, 1)
+	cache.Add(chunk2p, "foo", bm1, 1)
+	cache.Add(chunk2p, "bar", bm2, 2)
 
 	{ // chunk1 is not full
 		cached := cache.Lookup(chunk1p, "foo")
 		if cached != nil {
-			t.Error("Cached disabled for non-empty chunks", cached)
+			t.Error("Cached disabled for non-full chunks", cached)
 		}
 	}
 	{
 		cached := cache.Lookup(chunk2p, "foo")
-		if cached == nil || len(cached) != 1 {
-			t.Error("Expected 1 item cached", cached)
+		if cached == nil || cached[0] != 1 {
+			t.Error("Expected bitmap cached", cached)
 		}
 	}
 	{
 		cached := cache.Lookup(chunk2p, "bar")
-		if cached == nil || len(cached) != 2 {
-			t.Error("Expected 2 items cached", cached)
+		if cached == nil || cached[1] != 2 {
+			t.Error("Expected bitmap cached", cached)
 		}
 	}
 	{
 		cached := cache.Lookup(chunk1p, "foobar")
 		if cached != nil {
-			t.Error("Expected 0 item cached", cached)
+			t.Error("Expected nil cached", cached)
 		}
 	}
 }

src/chunklist.go

@@ -52,6 +52,20 @@ func (cl *ChunkList) lastChunk() *Chunk {
 	return cl.chunks[len(cl.chunks)-1]
 }
 
+// GetItems returns the first n items from the given chunks
+func GetItems(chunks []*Chunk, n int) []Item {
+	items := make([]Item, 0, n)
+	for _, chunk := range chunks {
+		for i := 0; i < chunk.count && len(items) < n; i++ {
+			items = append(items, chunk.items[i])
+		}
+		if len(items) >= n {
+			break
+		}
+	}
+	return items
+}
+
 // CountItems returns the total number of Items
 func CountItems(cs []*Chunk) int {
 	if len(cs) == 0 {
@@ -85,6 +99,21 @@ func (cl *ChunkList) Clear() {
 	cl.mutex.Unlock()
 }
 
+// ForEachItem iterates all items and applies fn to each one.
+// The done callback runs under the lock to safely update shared state.
+func (cl *ChunkList) ForEachItem(fn func(*Item), done func()) {
+	cl.mutex.Lock()
+	for _, chunk := range cl.chunks {
+		for i := 0; i < chunk.count; i++ {
+			fn(&chunk.items[i])
+		}
+	}
+	if done != nil {
+		done()
+	}
+	cl.mutex.Unlock()
+}
+
 // Snapshot returns immutable snapshot of the ChunkList
 func (cl *ChunkList) Snapshot(tail int) ([]*Chunk, int, bool) {
 	cl.mutex.Lock()

src/constants.go

@@ -34,19 +34,18 @@ const (
 	maxBgProcessesPerAction = 3
 
 	// Matcher
-	numPartitionsMultiplier = 8
-	maxPartitions           = 32
-	progressMinDuration     = 200 * time.Millisecond
+	progressMinDuration = 200 * time.Millisecond
 
 	// Capacity of each chunk
-	chunkSize int = 100
+	chunkSize     int = 1024
+	chunkBitWords     = (chunkSize + 63) / 64
 
 	// Pre-allocated memory slices to minimize GC
 	slab16Size int = 100 * 1024 // 200KB * 32 = 12.8MB
 	slab32Size int = 2048       // 8KB * 32 = 256KB
 
 	// Do not cache results of low selectivity queries
-	queryCacheMax int = chunkSize / 5
+	queryCacheMax int = chunkSize / 2
 
 	// Not to cache mergers with large lists
 	mergerCacheMax int = 100000
@@ -65,7 +64,6 @@ const (
 	EvtSearchNew
 	EvtSearchProgress
 	EvtSearchFin
-	EvtHeader
 	EvtReady
 	EvtQuit
 )

src/core.go

@@ -2,6 +2,7 @@
 package fzf
 
 import (
+	"fmt"
 	"maps"
 	"os"
 	"sync"
@@ -17,7 +18,6 @@ Reader   -> EvtReadNew        -> Matcher  (restart)
 Terminal -> EvtSearchNew:bool -> Matcher  (restart)
 Matcher  -> EvtSearchProgress -> Terminal (update info)
 Matcher  -> EvtSearchFin      -> Terminal (update list)
-Matcher  -> EvtHeader         -> Terminal (update header)
 */
 
 type revision struct {
@@ -56,6 +56,9 @@ func Run(opts *Options) (int, error) {
 		if opts.useTmux() {
 			return runTmux(os.Args, opts)
 		}
+		if opts.useZellij() {
+			return runZellij(os.Args, opts)
+		}
 
 		if needWinpty(opts) {
 			return runWinpty(os.Args, opts)
@@ -113,57 +116,57 @@ func Run(opts *Options) (int, error) {
 	cache := NewChunkCache()
 	var chunkList *ChunkList
 	var itemIndex int32
-	header := make([]string, 0, opts.HeaderLines)
+	// transformItem applies with-nth transformation to an item's raw data.
+	// It handles ANSI token propagation using prevLineAnsiState for cross-line continuity.
+	transformItem := func(item *Item, data []byte, transformer func([]Token, int32) string, index int32) {
+		tokens := Tokenize(byteString(data), opts.Delimiter)
+		if opts.Ansi && len(tokens) > 1 {
+			var ansiState *ansiState
+			if prevLineAnsiState != nil {
+				ansiStateDup := *prevLineAnsiState
+				ansiState = &ansiStateDup
+			}
+			for _, token := range tokens {
+				prevAnsiState := ansiState
+				_, _, ansiState = extractColor(token.text.ToString(), ansiState, nil)
+				if prevAnsiState != nil {
+					token.text.Prepend("\x1b[m" + prevAnsiState.ToString())
+				} else {
+					token.text.Prepend("\x1b[m")
+				}
+			}
+		}
+		transformed := transformer(tokens, index)
+		item.text, item.colors = ansiProcessor(stringBytes(transformed))
+
+		// We should not trim trailing whitespaces with background colors
+		var maxColorOffset int32
+		if item.colors != nil {
+			for _, ansi := range *item.colors {
+				if ansi.color.bg >= 0 {
+					maxColorOffset = max(maxColorOffset, ansi.offset[1])
+				}
+			}
+		}
+		item.text.TrimTrailingWhitespaces(int(maxColorOffset))
+	}
+
+	var nthTransformer func([]Token, int32) string
 	if opts.WithNth == nil {
 		chunkList = NewChunkList(cache, func(item *Item, data []byte) bool {
-			if len(header) < opts.HeaderLines {
-				header = append(header, byteString(data))
-				eventBox.Set(EvtHeader, header)
-				return false
-			}
 			item.text, item.colors = ansiProcessor(data)
 			item.text.Index = itemIndex
 			itemIndex++
 			return true
 		})
 	} else {
-		nthTransformer := opts.WithNth(opts.Delimiter)
+		nthTransformer = opts.WithNth(opts.Delimiter)
 		chunkList = NewChunkList(cache, func(item *Item, data []byte) bool {
-			tokens := Tokenize(byteString(data), opts.Delimiter)
-			if opts.Ansi && len(tokens) > 1 {
-				var ansiState *ansiState
-				if prevLineAnsiState != nil {
-					ansiStateDup := *prevLineAnsiState
-					ansiState = &ansiStateDup
-				}
-				for _, token := range tokens {
-					prevAnsiState := ansiState
-					_, _, ansiState = extractColor(token.text.ToString(), ansiState, nil)
-					if prevAnsiState != nil {
-						token.text.Prepend("\x1b[m" + prevAnsiState.ToString())
-					} else {
-						token.text.Prepend("\x1b[m")
-					}
-				}
+			if nthTransformer == nil {
+				item.text, item.colors = ansiProcessor(data)
+			} else {
+				transformItem(item, data, nthTransformer, itemIndex)
 			}
-			transformed := nthTransformer(tokens, itemIndex)
-			if len(header) < opts.HeaderLines {
-				header = append(header, transformed)
-				eventBox.Set(EvtHeader, header)
-				return false
-			}
-			item.text, item.colors = ansiProcessor(stringBytes(transformed))
-
-			// We should not trim trailing whitespaces with background colors
-			var maxColorOffset int32
-			if item.colors != nil {
-				for _, ansi := range *item.colors {
-					if ansi.color.bg >= 0 {
-						maxColorOffset = max(maxColorOffset, ansi.offset[1])
-					}
-				}
-			}
-			item.text.TrimTrailingWhitespaces(int(maxColorOffset))
 			item.text.Index = itemIndex
 			item.origText = &data
 			itemIndex++
@@ -193,13 +196,15 @@ func Run(opts *Options) (int, error) {
 	}
 
 	// Reader
-	streamingFilter := opts.Filter != nil && !sort && !opts.Tac && !opts.Sync
+	streamingFilter := opts.Filter != nil && !sort && !opts.Tac && !opts.Sync && opts.Bench == 0
 	var reader *Reader
+	var ingestionStart time.Time
 	if !streamingFilter {
 		reader = NewReader(func(data []byte) bool {
 			return chunkList.Push(data)
 		}, eventBox, executor, opts.ReadZero, opts.Filter == nil)
 
+		ingestionStart = time.Now()
 		readyChan := make(chan bool)
 		go reader.ReadSource(opts.Input, opts.WalkerRoot, opts.WalkerOpts, opts.WalkerSkip, initialReload, initialEnv, readyChan)
 		<-readyChan
@@ -236,15 +241,17 @@ func Run(opts *Options) (int, error) {
 		denylist = make(map[int32]struct{})
 		denyMutex.Unlock()
 	}
+	headerLines := int32(opts.HeaderLines)
+	headerUpdated := false
 	patternBuilder := func(runes []rune) *Pattern {
 		denyMutex.Lock()
 		denylistCopy := maps.Clone(denylist)
 		denyMutex.Unlock()
 		return BuildPattern(cache, patternCache,
 			opts.Fuzzy, opts.FuzzyAlgo, opts.Extended, opts.Case, opts.Normalize, forward, withPos,
-			opts.Filter == nil, nth, opts.Delimiter, inputRevision, runes, denylistCopy)
+			opts.Filter == nil, nth, opts.Delimiter, inputRevision, runes, denylistCopy, headerLines)
 	}
-	matcher := NewMatcher(cache, patternBuilder, sort, opts.Tac, eventBox, inputRevision)
+	matcher := NewMatcher(cache, patternBuilder, sort, opts.Tac, eventBox, inputRevision, opts.Threads)
 
 	// Filtering mode
 	if opts.Filter != nil {
@@ -265,8 +272,11 @@ func Run(opts *Options) (int, error) {
 				func(runes []byte) bool {
 					item := Item{}
 					if chunkList.trans(&item, runes) {
+						if item.Index() < headerLines {
+							return false
+						}
 						mutex.Lock()
-						if result, _, _ := pattern.MatchItem(&item, false, slab); result != nil {
+						if result, _, _ := pattern.MatchItem(&item, false, slab); result.item != nil {
 							opts.Printer(transformer(&item))
 							found = true
 						}
@@ -278,9 +288,51 @@ func Run(opts *Options) (int, error) {
 		} else {
 			eventBox.Unwatch(EvtReadNew)
 			eventBox.WaitFor(EvtReadFin)
+			ingestionTime := time.Since(ingestionStart)
 
 			// NOTE: Streaming filter is inherently not compatible with --tail
 			snapshot, _, _ := chunkList.Snapshot(opts.Tail)
+
+			if opts.Bench > 0 {
+				// Benchmark mode: repeat scan for the given duration
+				totalItems := CountItems(snapshot)
+				var matchCount int
+				var times []time.Duration
+				deadline := time.Now().Add(opts.Bench)
+				for time.Now().Before(deadline) {
+					cache.Clear()
+					start := time.Now()
+					result := matcher.scan(MatchRequest{
+						chunks:  snapshot,
+						pattern: pattern})
+					times = append(times, time.Since(start))
+					matchCount = result.merger.Length()
+				}
+				// Print stats
+				var total time.Duration
+				minD, maxD := times[0], times[0]
+				for _, d := range times {
+					total += d
+					if d < minD {
+						minD = d
+					}
+					if d > maxD {
+						maxD = d
+					}
+				}
+				avg := total / time.Duration(len(times))
+				selectivity := float64(matchCount) / float64(totalItems) * 100
+				fmt.Printf("  %d iterations  avg: %.2fms  min: %.2fms  max: %.2fms  total: %.2fs  items: %d  matches: %d (%.2f%%)  ingestion: %.2fms\n",
+					len(times),
+					float64(avg.Microseconds())/1000,
+					float64(minD.Microseconds())/1000,
+					float64(maxD.Microseconds())/1000,
+					total.Seconds(),
+					totalItems, matchCount, selectivity,
+					float64(ingestionTime.Microseconds())/1000)
+				return ExitOk, nil
+			}
+
 			result := matcher.scan(MatchRequest{
 				chunks:  snapshot,
 				pattern: pattern})
@@ -330,10 +382,11 @@ func Run(opts *Options) (int, error) {
 	query := []rune{}
 	determine := func(final bool) {
 		if heightUnknown {
-			if total >= maxFit || final {
+			items := max(0, total-int(headerLines))
+			if items >= maxFit || final {
 				deferred = false
 				heightUnknown = false
-				terminal.startChan <- fitpad{min(total, maxFit), padHeight}
+				terminal.startChan <- fitpad{min(items, maxFit), padHeight}
 			}
 		} else if deferred {
 			deferred = false
@@ -349,11 +402,11 @@ func Run(opts *Options) (int, error) {
 			clearDenylist()
 		}
 		reading = true
+		headerUpdated = false
 		startTick = ticks
 		chunkList.Clear()
 		itemIndex = 0
 		inputRevision.bumpMajor()
-		header = make([]string, 0, opts.HeaderLines)
 		readyChan := make(chan bool)
 		go reader.restart(command, environ, readyChan)
 		<-readyChan
@@ -411,16 +464,24 @@ func Run(opts *Options) (int, error) {
 						snapshotRevision = inputRevision
 					}
 					total = count
-					terminal.UpdateCount(total, !reading, value.(*string))
+					terminal.UpdateCount(max(0, total-int(headerLines)), !reading, value.(*string))
+					if headerLines > 0 && !headerUpdated {
+						terminal.UpdateHeader(GetItems(snapshot, int(headerLines)))
+						headerUpdated = int32(total) >= headerLines
+					}
 					if heightUnknown && !deferred {
 						determine(!reading)
 					}
-					matcher.Reset(snapshot, input(), false, !reading, sort, snapshotRevision)
+					if !useSnapshot || evt == EvtReadFin {
+						matcher.Reset(snapshot, input(), false, !reading, sort, snapshotRevision)
+					}
 
 				case EvtSearchNew:
 					var command *commandSpec
 					var environ []string
 					var changed bool
+					headerLinesChanged := false
+					withNthChanged := false
 					switch val := value.(type) {
 					case searchRequest:
 						sort = val.sort
@@ -441,6 +502,40 @@ func Run(opts *Options) (int, error) {
 							nth = *val.nth
 							bump = true
 						}
+						if val.headerLines != nil {
+							headerLines = int32(*val.headerLines)
+							headerUpdated = false
+							headerLinesChanged = true
+							bump = true
+						}
+						if val.withNth != nil {
+							newTransformer := val.withNth.fn
+							// Cancel any in-flight scan and block the terminal from reading
+							// items before mutating them in-place. Snapshot shares middle
+							// chunk pointers, so the matcher and terminal can race with us.
+							matcher.CancelScan()
+							terminal.PauseRendering()
+							// Reset cross-line ANSI state before re-processing all items
+							lineAnsiState = nil
+							prevLineAnsiState = nil
+							chunkList.ForEachItem(func(item *Item) {
+								origBytes := *item.origText
+								savedIndex := item.Index()
+								if newTransformer != nil {
+									transformItem(item, origBytes, newTransformer, savedIndex)
+								} else {
+									item.text, item.colors = ansiProcessor(origBytes)
+								}
+								item.text.Index = savedIndex
+								item.transformed = nil
+							}, func() {
+								nthTransformer = newTransformer
+							})
+							terminal.ResumeRendering()
+							matcher.ResumeScan()
+							withNthChanged = true
+							bump = true
+						}
 						if bump {
 							patternCache = make(map[string]*Pattern)
 							cache.Clear()
@@ -477,6 +572,16 @@ func Run(opts *Options) (int, error) {
 							snapshotRevision = inputRevision
 						}
 					}
+					if headerLinesChanged {
+						terminal.UpdateCount(max(0, total-int(headerLines)), !reading, nil)
+						if headerLines > 0 {
+							terminal.UpdateHeader(GetItems(snapshot, int(headerLines)))
+						} else {
+							terminal.UpdateHeader(nil)
+						}
+					} else if withNthChanged && headerLines > 0 {
+						terminal.UpdateHeader(GetItems(snapshot, int(headerLines)))
+					}
 					matcher.Reset(snapshot, input(), true, !reading, sort, snapshotRevision)
 					delay = false
 
@@ -486,11 +591,6 @@ func Run(opts *Options) (int, error) {
 						terminal.UpdateProgress(val)
 					}
 
-				case EvtHeader:
-					headerPadded := make([]string, opts.HeaderLines)
-					copy(headerPadded, value.([]string))
-					terminal.UpdateHeader(headerPadded)
-
 				case EvtSearchFin:
 					switch val := value.(type) {
 					case MatchResult:

src/matcher.go

@@ -3,8 +3,8 @@ package fzf
 import (
 	"fmt"
 	"runtime"
-	"sort"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"github.com/junegunn/fzf/src/util"
@@ -43,8 +43,11 @@ type Matcher struct {
 	reqBox         *util.EventBox
 	partitions     int
 	slab           []*util.Slab
+	sortBuf        [][]Result
 	mergerCache    map[string]MatchResult
 	revision       revision
+	scanMutex      sync.Mutex
+	cancelScan     *util.AtomicBool
 }
 
 const (
@@ -54,8 +57,11 @@ const (
 
 // NewMatcher returns a new Matcher
 func NewMatcher(cache *ChunkCache, patternBuilder func([]rune) *Pattern,
-	sort bool, tac bool, eventBox *util.EventBox, revision revision) *Matcher {
-	partitions := min(numPartitionsMultiplier*runtime.NumCPU(), maxPartitions)
+	sort bool, tac bool, eventBox *util.EventBox, revision revision, threads int) *Matcher {
+	partitions := runtime.NumCPU()
+	if threads > 0 {
+		partitions = threads
+	}
 	return &Matcher{
 		cache:          cache,
 		patternBuilder: patternBuilder,
@@ -65,8 +71,10 @@ func NewMatcher(cache *ChunkCache, patternBuilder func([]rune) *Pattern,
 		reqBox:         util.NewEventBox(),
 		partitions:     partitions,
 		slab:           make([]*util.Slab, partitions),
+		sortBuf:        make([][]Result, partitions),
 		mergerCache:    make(map[string]MatchResult),
-		revision:       revision}
+		revision:       revision,
+		cancelScan:     util.NewAtomicBool(false)}
 }
 
 // Loop puts Matcher in action
@@ -126,7 +134,9 @@ func (m *Matcher) Loop() {
 		}
 
 		if result.merger == nil {
+			m.scanMutex.Lock()
 			result = m.scan(request)
+			m.scanMutex.Unlock()
 		}
 
 		if !result.cancelled {
@@ -139,27 +149,6 @@ func (m *Matcher) Loop() {
 	}
 }
 
-func (m *Matcher) sliceChunks(chunks []*Chunk) [][]*Chunk {
-	partitions := m.partitions
-	perSlice := len(chunks) / partitions
-
-	if perSlice == 0 {
-		partitions = len(chunks)
-		perSlice = 1
-	}
-
-	slices := make([][]*Chunk, partitions)
-	for i := 0; i < partitions; i++ {
-		start := i * perSlice
-		end := start + perSlice
-		if i == partitions-1 {
-			end = len(chunks)
-		}
-		slices[i] = chunks[start:end]
-	}
-	return slices
-}
-
 type partialResult struct {
 	index   int
 	matches []Result
@@ -174,7 +163,7 @@ func (m *Matcher) scan(request MatchRequest) MatchResult {
 		return MatchResult{m, m, false}
 	}
 	pattern := request.pattern
-	passMerger := PassMerger(&request.chunks, m.tac, request.revision)
+	passMerger := PassMerger(&request.chunks, m.tac, request.revision, pattern.startIndex)
 	if pattern.IsEmpty() {
 		return MatchResult{passMerger, passMerger, false}
 	}
@@ -183,43 +172,37 @@ func (m *Matcher) scan(request MatchRequest) MatchResult {
 	maxIndex := request.chunks[numChunks-1].lastIndex(minIndex)
 	cancelled := util.NewAtomicBool(false)
 
-	slices := m.sliceChunks(request.chunks)
-	numSlices := len(slices)
-	resultChan := make(chan partialResult, numSlices)
+	numWorkers := min(m.partitions, numChunks)
+	var nextChunk atomic.Int32
+	resultChan := make(chan partialResult, numWorkers)
 	countChan := make(chan int, numChunks)
 	waitGroup := sync.WaitGroup{}
 
-	for idx, chunks := range slices {
+	for idx := range numWorkers {
 		waitGroup.Add(1)
 		if m.slab[idx] == nil {
 			m.slab[idx] = util.MakeSlab(slab16Size, slab32Size)
 		}
-		go func(idx int, slab *util.Slab, chunks []*Chunk) {
-			defer func() { waitGroup.Done() }()
-			count := 0
-			allMatches := make([][]Result, len(chunks))
-			for idx, chunk := range chunks {
-				matches := request.pattern.Match(chunk, slab)
-				allMatches[idx] = matches
-				count += len(matches)
+		go func(idx int, slab *util.Slab) {
+			defer waitGroup.Done()
+			var matches []Result
+			for {
+				ci := int(nextChunk.Add(1)) - 1
+				if ci >= numChunks {
+					break
+				}
+				chunkMatches := request.pattern.Match(request.chunks[ci], slab)
+				matches = append(matches, chunkMatches...)
 				if cancelled.Get() {
 					return
 				}
-				countChan <- len(matches)
-			}
-			sliceMatches := make([]Result, 0, count)
-			for _, matches := range allMatches {
-				sliceMatches = append(sliceMatches, matches...)
+				countChan <- len(chunkMatches)
 			}
 			if m.sort && request.pattern.sortable {
-				if m.tac {
-					sort.Sort(ByRelevanceTac(sliceMatches))
-				} else {
-					sort.Sort(ByRelevance(sliceMatches))
-				}
+				m.sortBuf[idx] = radixSortResults(matches, m.tac, m.sortBuf[idx])
 			}
-			resultChan <- partialResult{idx, sliceMatches}
-		}(idx, m.slab[idx], chunks)
+			resultChan <- partialResult{idx, matches}
+		}(idx, m.slab[idx])
 	}
 
 	wait := func() bool {
@@ -238,7 +221,7 @@ func (m *Matcher) scan(request MatchRequest) MatchResult {
 			break
 		}
 
-		if m.reqBox.Peek(reqReset) {
+		if m.cancelScan.Get() || m.reqBox.Peek(reqReset) {
 			return MatchResult{nil, nil, wait()}
 		}
 
@@ -247,8 +230,8 @@ func (m *Matcher) scan(request MatchRequest) MatchResult {
 		}
 	}
 
-	partialResults := make([][]Result, numSlices)
-	for range slices {
+	partialResults := make([][]Result, numWorkers)
+	for range numWorkers {
 		partialResult := <-resultChan
 		partialResults[partialResult.index] = partialResult.matches
 	}
@@ -269,6 +252,20 @@ func (m *Matcher) Reset(chunks []*Chunk, patternRunes []rune, cancel bool, final
 	m.reqBox.Set(event, MatchRequest{chunks, pattern, final, sort, revision})
 }
 
+// CancelScan cancels any in-flight scan, waits for it to finish,
+// and prevents new scans from starting until ResumeScan is called.
+// This is used to safely mutate shared items (e.g., during with-nth changes).
+func (m *Matcher) CancelScan() {
+	m.cancelScan.Set(true)
+	m.scanMutex.Lock()
+	m.cancelScan.Set(false)
+}
+
+// ResumeScan allows scans to proceed again after CancelScan.
+func (m *Matcher) ResumeScan() {
+	m.scanMutex.Unlock()
+}
+
 func (m *Matcher) Stop() {
 	m.reqBox.Set(reqQuit, nil)
 }

src/merger.go

@@ -10,42 +10,46 @@ func EmptyMerger(revision revision) *Merger {
 // Merger holds a set of locally sorted lists of items and provides the view of
 // a single, globally-sorted list
 type Merger struct {
-	pattern  *Pattern
-	lists    [][]Result
-	merged   []Result
-	chunks   *[]*Chunk
-	cursors  []int
-	sorted   bool
-	tac      bool
-	final    bool
-	count    int
-	pass     bool
-	revision revision
-	minIndex int32
-	maxIndex int32
+	pattern    *Pattern
+	lists      [][]Result
+	merged     []Result
+	chunks     *[]*Chunk
+	cursors    []int
+	sorted     bool
+	tac        bool
+	final      bool
+	count      int
+	pass       bool
+	startIndex int
+	revision   revision
+	minIndex   int32
+	maxIndex   int32
 }
 
 // PassMerger returns a new Merger that simply returns the items in the
-// original order
-func PassMerger(chunks *[]*Chunk, tac bool, revision revision) *Merger {
+// original order. startIndex items are skipped from the beginning.
+func PassMerger(chunks *[]*Chunk, tac bool, revision revision, startIndex int32) *Merger {
 	var minIndex, maxIndex int32
 	if len(*chunks) > 0 {
 		minIndex = (*chunks)[0].items[0].Index()
 		maxIndex = (*chunks)[len(*chunks)-1].lastIndex(minIndex)
 	}
+	si := int(startIndex)
 	mg := Merger{
-		pattern:  nil,
-		chunks:   chunks,
-		tac:      tac,
-		count:    0,
-		pass:     true,
-		revision: revision,
-		minIndex: minIndex,
-		maxIndex: maxIndex}
+		pattern:    nil,
+		chunks:     chunks,
+		tac:        tac,
+		count:      0,
+		pass:       true,
+		startIndex: si,
+		revision:   revision,
+		minIndex:   minIndex + startIndex,
+		maxIndex:   maxIndex}
 
 	for _, chunk := range *mg.chunks {
 		mg.count += chunk.count
 	}
+	mg.count = max(0, mg.count-si)
 	return &mg
 }
 
@@ -113,6 +117,7 @@ func (mg *Merger) Get(idx int) Result {
 		if mg.tac {
 			idx = mg.count - idx - 1
 		}
+		idx += mg.startIndex
 		firstChunk := (*mg.chunks)[0]
 		if firstChunk.count < chunkSize && idx >= firstChunk.count {
 			idx -= firstChunk.count
@@ -131,14 +136,7 @@ func (mg *Merger) Get(idx int) Result {
 	if mg.tac {
 		idx = mg.count - idx - 1
 	}
-	for _, list := range mg.lists {
-		numItems := len(list)
-		if idx < numItems {
-			return list[idx]
-		}
-		idx -= numItems
-	}
-	panic(fmt.Sprintf("Index out of bounds (unsorted, %d/%d)", idx, mg.count))
+	return mg.mergedGet(idx)
 }
 
 func (mg *Merger) ToMap() map[int32]Result {
@@ -166,7 +164,7 @@ func (mg *Merger) mergedGet(idx int) Result {
 			}
 			if cursor >= 0 {
 				rank := list[cursor]
-				if minIdx < 0 || compareRanks(rank, minRank, mg.tac) {
+				if minIdx < 0 || mg.sorted && compareRanks(rank, minRank, mg.tac) || !mg.sorted && rank.item.Index() < minRank.item.Index() {
 					minRank = rank
 					minIdx = listIdx
 				}

src/merger_test.go

@@ -54,10 +54,25 @@ func buildLists(partiallySorted bool) ([][]Result, []Result) {
 }
 
 func TestMergerUnsorted(t *testing.T) {
-	lists, items := buildLists(false)
+	lists, _ := buildLists(false)
+
+	// Sort each list by index to simulate real worker behavior
+	// (workers process chunks in ascending order via nextChunk.Add(1))
+	for _, list := range lists {
+		sort.Slice(list, func(i, j int) bool {
+			return list[i].item.Index() < list[j].item.Index()
+		})
+	}
+	items := []Result{}
+	for _, list := range lists {
+		items = append(items, list...)
+	}
+	sort.Slice(items, func(i, j int) bool {
+		return items[i].item.Index() < items[j].item.Index()
+	})
 	cnt := len(items)
 
-	// Not sorted: same order
+	// Not sorted: items in ascending index order
 	mg := NewMerger(nil, lists, false, false, revision{}, 0, 0)
 	assert(t, cnt == mg.Length(), "Invalid Length")
 	for i := range cnt {

src/options.go

@@ -8,6 +8,7 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+	"time"
 	"unicode"
 
 	"github.com/junegunn/fzf/src/algo"
@@ -74,9 +75,10 @@ Usage: fzf [options]
     --min-height=HEIGHT[+]   Minimum height when --height is given as a percentage.
                              Add '+' to automatically increase the value
                              according to the other layout options (default: 10+).
-    --tmux[=OPTS]            Start fzf in a tmux popup (requires tmux 3.3+)
+    --popup[=OPTS]           Start fzf in a popup window (requires tmux 3.3+ or Zellij 0.44+)
                              [center|top|bottom|left|right][,SIZE[%]][,SIZE[%]]
                              [,border-native] (default: center,50%)
+    --tmux[=OPTS]            Alias for --popup
 
   LAYOUT
     --layout=LAYOUT          Choose layout: [default|reverse|reverse-list]
@@ -100,6 +102,7 @@ Usage: fzf [options]
     --no-multi-line          Disable multi-line display of items when using --read0
     --raw                    Enable raw mode (show non-matching items)
     --track                  Track the current selection when the result is updated
+    --id-nth=N[,..]          Define item identity fields for cross-reload operations
     --tac                    Reverse the order of the input
     --gap[=N]                Render empty lines between each item
     --gap-line[=STR]         Draw horizontal line on each gap using the string
@@ -415,7 +418,7 @@ func parseTmuxOptions(arg string, index int) (*tmuxOptions, error) {
 	var err error
 	opts := defaultTmuxOptions(index)
 	tokens := splitRegexp.Split(arg, -1)
-	errorToReturn := errors.New("invalid tmux option: " + arg + " (expected: [center|top|bottom|left|right][,SIZE[%]][,SIZE[%][,border-native]])")
+	errorToReturn := errors.New("invalid popup option: " + arg + " (expected: [center|top|bottom|left|right][,SIZE[%]][,SIZE[%][,border-native]])")
 	if len(tokens) == 0 || len(tokens) > 4 {
 		return nil, errorToReturn
 	}
@@ -587,11 +590,13 @@ type Options struct {
 	FreezeLeft        int
 	FreezeRight       int
 	WithNth           func(Delimiter) func([]Token, int32) string
+	WithNthExpr       string
 	AcceptNth         func(Delimiter) func([]Token, int32) string
 	Delimiter         Delimiter
 	Sort              int
 	Raw               bool
 	Track             trackOption
+	IdNth             []Range
 	Tac               bool
 	Tail              int
 	Criteria          []criterion
@@ -677,6 +682,8 @@ type Options struct {
 	WalkerSkip        []string
 	Version           bool
 	Help              bool
+	Threads           int
+	Bench             time.Duration
 	CPUProfile        string
 	MEMProfile        string
 	BlockProfile      string
@@ -1606,7 +1613,7 @@ func parseWalkerOpts(str string) (walkerOpts, error) {
 }
 
 var (
-	executeRegexp    *regexp.Regexp
+	argActionRegexp  *regexp.Regexp
 	splitRegexp      *regexp.Regexp
 	actionNameRegexp *regexp.Regexp
 )
@@ -1625,8 +1632,8 @@ const (
 )
 
 func init() {
-	executeRegexp = regexp.MustCompile(
-		`(?si)[:+](become|execute(?:-multi|-silent)?|reload(?:-sync)?|preview|(?:change|bg-transform|transform)-(?:query|prompt|(?:border|list|preview|input|header|footer)-label|header|footer|search|nth|pointer|ghost)|bg-transform|transform|change-(?:preview-window|preview|multi)|(?:re|un|toggle-)bind|pos|put|print|search|trigger)`)
+	argActionRegexp = regexp.MustCompile(
+		`(?si)[:+](become|execute(?:-multi|-silent)?|reload(?:-sync)?|preview|(?:change|bg-transform|transform)-(?:query|prompt|(?:border|list|preview|input|header|footer)-label|header-lines|header|footer|search|with-nth|nth|pointer|ghost)|bg-transform|transform|change-(?:preview-window|preview|multi)|(?:re|un|toggle-)bind|pos|put|print|search|trigger)`)
 	splitRegexp = regexp.MustCompile("[,:]+")
 	actionNameRegexp = regexp.MustCompile("(?i)^[a-z-]+")
 }
@@ -1635,7 +1642,7 @@ func maskActionContents(action string) string {
 	masked := ""
 Loop:
 	for len(action) > 0 {
-		loc := executeRegexp.FindStringIndex(action)
+		loc := argActionRegexp.FindStringIndex(action)
 		if loc == nil {
 			masked += action
 			break
@@ -1690,7 +1697,7 @@ Loop:
 }
 
 func parseSingleActionList(str string) ([]*action, error) {
-	// We prepend a colon to satisfy executeRegexp and remove it later
+	// We prepend a colon to satisfy argActionRegexp and remove it later
 	masked := maskActionContents(":" + str)[1:]
 	return parseActionList(masked, str, []*action{}, false)
 }
@@ -2037,6 +2044,8 @@ func isExecuteAction(str string) actionType {
 		return actPreview
 	case "change-header":
 		return actChangeHeader
+	case "change-header-lines":
+		return actChangeHeaderLines
 	case "change-footer":
 		return actChangeFooter
 	case "change-list-label":
@@ -2067,6 +2076,8 @@ func isExecuteAction(str string) actionType {
 		return actChangeMulti
 	case "change-nth":
 		return actChangeNth
+	case "change-with-nth":
+		return actChangeWithNth
 	case "pos":
 		return actPosition
 	case "execute":
@@ -2097,10 +2108,14 @@ func isExecuteAction(str string) actionType {
 		return actTransformFooter
 	case "transform-header":
 		return actTransformHeader
+	case "transform-header-lines":
+		return actTransformHeaderLines
 	case "transform-ghost":
 		return actTransformGhost
 	case "transform-nth":
 		return actTransformNth
+	case "transform-with-nth":
+		return actTransformWithNth
 	case "transform-pointer":
 		return actTransformPointer
 	case "transform-prompt":
@@ -2127,10 +2142,14 @@ func isExecuteAction(str string) actionType {
 		return actBgTransformFooter
 	case "bg-transform-header":
 		return actBgTransformHeader
+	case "bg-transform-header-lines":
+		return actBgTransformHeaderLines
 	case "bg-transform-ghost":
 		return actBgTransformGhost
 	case "bg-transform-nth":
 		return actBgTransformNth
+	case "bg-transform-with-nth":
+		return actBgTransformWithNth
 	case "bg-transform-pointer":
 		return actBgTransformPointer
 	case "bg-transform-prompt":
@@ -2618,7 +2637,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 			opts.Version = true
 		case "--no-winpty":
 			opts.NoWinpty = true
-		case "--tmux":
+		case "--tmux", "--popup":
 			given, str := optionalNextString()
 			if given {
 				if opts.Tmux, err = parseTmuxOptions(str, index); err != nil {
@@ -2627,7 +2646,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 			} else {
 				opts.Tmux = defaultTmuxOptions(index)
 			}
-		case "--no-tmux":
+		case "--no-tmux", "--no-popup":
 			opts.Tmux = nil
 		case "--tty-default":
 			if opts.TtyDefault, err = nextString("tty device name required"); err != nil {
@@ -2772,6 +2791,7 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 			if opts.WithNth, err = nthTransformer(str); err != nil {
 				return err
 			}
+			opts.WithNthExpr = str
 		case "--accept-nth":
 			str, err := nextString("nth expression required")
 			if err != nil {
@@ -2794,6 +2814,16 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 			opts.Track = trackEnabled
 		case "--no-track":
 			opts.Track = trackDisabled
+		case "--id-nth":
+			str, err := nextString("nth expression required")
+			if err != nil {
+				return err
+			}
+			if opts.IdNth, err = splitNth(str); err != nil {
+				return err
+			}
+		case "--no-id-nth":
+			opts.IdNth = nil
 		case "--tac":
 			opts.Tac = true
 		case "--no-tac":
@@ -3367,6 +3397,23 @@ func parseOptions(index *int, opts *Options, allArgs []string) error {
 				return err
 			}
 			opts.WalkerSkip = filterNonEmpty(strings.Split(str, ","))
+		case "--threads":
+			if opts.Threads, err = nextInt("number of threads required"); err != nil {
+				return err
+			}
+			if opts.Threads < 0 {
+				return errors.New("--threads must be a positive integer")
+			}
+		case "--bench":
+			str, err := nextString("duration required (e.g. 3s, 500ms)")
+			if err != nil {
+				return err
+			}
+			dur, err := time.ParseDuration(str)
+			if err != nil {
+				return errors.New("invalid duration for --bench: " + str)
+			}
+			opts.Bench = dur
 		case "--profile-cpu":
 			if opts.CPUProfile, err = nextString("file path required: cpu"); err != nil {
 				return err
@@ -3581,6 +3628,10 @@ func (opts *Options) useTmux() bool {
 	return opts.Tmux != nil && len(os.Getenv("TMUX")) > 0 && opts.Tmux.index >= opts.Height.index
 }
 
+func (opts *Options) useZellij() bool {
+	return opts.Tmux != nil && len(os.Getenv("ZELLIJ")) > 0 && opts.Tmux.index >= opts.Height.index
+}
+
 func (opts *Options) noSeparatorLine() bool {
 	if opts.Inputless {
 		return true

src/pattern.go

@@ -61,9 +61,12 @@ type Pattern struct {
 	delimiter     Delimiter
 	nth           []Range
 	revision      revision
-	procFun       map[termType]algo.Algo
+	procFun       [6]algo.Algo
 	cache         *ChunkCache
 	denylist      map[int32]struct{}
+	startIndex    int32
+	directAlgo    algo.Algo
+	directTerm    *term
 }
 
 var _splitRegex *regexp.Regexp
@@ -74,7 +77,7 @@ func init() {
 
 // BuildPattern builds Pattern object from the given arguments
 func BuildPattern(cache *ChunkCache, patternCache map[string]*Pattern, fuzzy bool, fuzzyAlgo algo.Algo, extended bool, caseMode Case, normalize bool, forward bool,
-	withPos bool, cacheable bool, nth []Range, delimiter Delimiter, revision revision, runes []rune, denylist map[int32]struct{}) *Pattern {
+	withPos bool, cacheable bool, nth []Range, delimiter Delimiter, revision revision, runes []rune, denylist map[int32]struct{}, startIndex int32) *Pattern {
 
 	var asString string
 	if extended {
@@ -146,9 +149,11 @@ func BuildPattern(cache *ChunkCache, patternCache map[string]*Pattern, fuzzy boo
 		delimiter:     delimiter,
 		cache:         cache,
 		denylist:      denylist,
-		procFun:       make(map[termType]algo.Algo)}
+		startIndex:    startIndex,
+	}
 
 	ptr.cacheKey = ptr.buildCacheKey()
+	ptr.directAlgo, ptr.directTerm = ptr.buildDirectAlgo(fuzzyAlgo)
 	ptr.procFun[termFuzzy] = fuzzyAlgo
 	ptr.procFun[termEqual] = algo.EqualMatch
 	ptr.procFun[termExact] = algo.ExactMatchNaive
@@ -272,6 +277,22 @@ func (p *Pattern) buildCacheKey() string {
 	return strings.Join(cacheableTerms, "\t")
 }
 
+// buildDirectAlgo returns the algo function and term for the direct fast path
+// in matchChunk. Returns (nil, nil) if the pattern is not suitable.
+// Requirements: extended mode, single term set with single non-inverse fuzzy term, no nth.
+func (p *Pattern) buildDirectAlgo(fuzzyAlgo algo.Algo) (algo.Algo, *term) {
+	if !p.extended || len(p.nth) > 0 {
+		return nil, nil
+	}
+	if len(p.termSets) == 1 && len(p.termSets[0]) == 1 {
+		t := &p.termSets[0][0]
+		if !t.inv && t.typ == termFuzzy {
+			return fuzzyAlgo, t
+		}
+	}
+	return nil, nil
+}
+
 // CacheKey is used to build string to be used as the key of result cache
 func (p *Pattern) CacheKey() string {
 	return p.cacheKey
@@ -279,84 +300,104 @@ func (p *Pattern) CacheKey() string {
 
 // Match returns the list of matches Items in the given Chunk
 func (p *Pattern) Match(chunk *Chunk, slab *util.Slab) []Result {
-	// ChunkCache: Exact match
 	cacheKey := p.CacheKey()
+
+	// Bitmap cache: exact match or prefix/suffix
+	var cachedBitmap *ChunkBitmap
 	if p.cacheable {
-		if cached := p.cache.Lookup(chunk, cacheKey); cached != nil {
-			return cached
-		}
+		cachedBitmap = p.cache.Lookup(chunk, cacheKey)
+	}
+	if cachedBitmap == nil {
+		cachedBitmap = p.cache.Search(chunk, cacheKey)
 	}
 
-	// Prefix/suffix cache
-	space := p.cache.Search(chunk, cacheKey)
-
-	matches := p.matchChunk(chunk, space, slab)
+	matches, bitmap := p.matchChunk(chunk, cachedBitmap, slab)
 
 	if p.cacheable {
-		p.cache.Add(chunk, cacheKey, matches)
+		p.cache.Add(chunk, cacheKey, bitmap, len(matches))
 	}
 	return matches
 }
 
-func (p *Pattern) matchChunk(chunk *Chunk, space []Result, slab *util.Slab) []Result {
+func (p *Pattern) matchChunk(chunk *Chunk, cachedBitmap *ChunkBitmap, slab *util.Slab) ([]Result, ChunkBitmap) {
 	matches := []Result{}
+	var bitmap ChunkBitmap
+
+	// Skip header items in chunks that contain them
+	startIdx := 0
+	if p.startIndex > 0 && chunk.count > 0 && chunk.items[0].Index() < p.startIndex {
+		startIdx = int(p.startIndex - chunk.items[0].Index())
+		if startIdx >= chunk.count {
+			return matches, bitmap
+		}
+	}
+
+	hasCachedBitmap := cachedBitmap != nil
+
+	// Fast path: single fuzzy term, no nth, no denylist.
+	// Calls the algo function directly, bypassing MatchItem/extendedMatch/iter
+	// and avoiding per-match []Offset heap allocation.
+	if p.directAlgo != nil && len(p.denylist) == 0 {
+		t := p.directTerm
+		for idx := startIdx; idx < chunk.count; idx++ {
+			if hasCachedBitmap && cachedBitmap[idx/64]&(uint64(1)<<(idx%64)) == 0 {
+				continue
+			}
+			res, _ := p.directAlgo(t.caseSensitive, t.normalize, p.forward,
+				&chunk.items[idx].text, t.text, p.withPos, slab)
+			if res.Start >= 0 {
+				bitmap[idx/64] |= uint64(1) << (idx % 64)
+				matches = append(matches, buildResultFromBounds(
+					&chunk.items[idx], res.Score,
+					int(res.Start), int(res.End), int(res.End), true))
+			}
+		}
+		return matches, bitmap
+	}
 
 	if len(p.denylist) == 0 {
-		// Huge code duplication for minimizing unnecessary map lookups
-		if space == nil {
-			for idx := 0; idx < chunk.count; idx++ {
-				if match, _, _ := p.MatchItem(&chunk.items[idx], p.withPos, slab); match != nil {
-					matches = append(matches, *match)
-				}
+		for idx := startIdx; idx < chunk.count; idx++ {
+			if hasCachedBitmap && cachedBitmap[idx/64]&(uint64(1)<<(idx%64)) == 0 {
+				continue
 			}
-		} else {
-			for _, result := range space {
-				if match, _, _ := p.MatchItem(result.item, p.withPos, slab); match != nil {
-					matches = append(matches, *match)
-				}
+			if match, _, _ := p.MatchItem(&chunk.items[idx], p.withPos, slab); match.item != nil {
+				bitmap[idx/64] |= uint64(1) << (idx % 64)
+				matches = append(matches, match)
 			}
 		}
-		return matches
+		return matches, bitmap
 	}
 
-	if space == nil {
-		for idx := 0; idx < chunk.count; idx++ {
-			if _, prs := p.denylist[chunk.items[idx].Index()]; prs {
-				continue
-			}
-			if match, _, _ := p.MatchItem(&chunk.items[idx], p.withPos, slab); match != nil {
-				matches = append(matches, *match)
-			}
+	for idx := startIdx; idx < chunk.count; idx++ {
+		if hasCachedBitmap && cachedBitmap[idx/64]&(uint64(1)<<(idx%64)) == 0 {
+			continue
 		}
-	} else {
-		for _, result := range space {
-			if _, prs := p.denylist[result.item.Index()]; prs {
-				continue
-			}
-			if match, _, _ := p.MatchItem(result.item, p.withPos, slab); match != nil {
-				matches = append(matches, *match)
-			}
+		if _, prs := p.denylist[chunk.items[idx].Index()]; prs {
+			continue
+		}
+		if match, _, _ := p.MatchItem(&chunk.items[idx], p.withPos, slab); match.item != nil {
+			bitmap[idx/64] |= uint64(1) << (idx % 64)
+			matches = append(matches, match)
 		}
 	}
-	return matches
+	return matches, bitmap
 }
 
-// MatchItem returns true if the Item is a match
-func (p *Pattern) MatchItem(item *Item, withPos bool, slab *util.Slab) (*Result, []Offset, *[]int) {
+// MatchItem returns the match result if the Item is a match.
+// A zero-value Result (with item == nil) indicates no match.
+func (p *Pattern) MatchItem(item *Item, withPos bool, slab *util.Slab) (Result, []Offset, *[]int) {
 	if p.extended {
 		if offsets, bonus, pos := p.extendedMatch(item, withPos, slab); len(offsets) == len(p.termSets) {
-			result := buildResult(item, offsets, bonus)
-			return &result, offsets, pos
+			return buildResult(item, offsets, bonus), offsets, pos
 		}
-		return nil, nil, nil
+		return Result{}, nil, nil
 	}
 	offset, bonus, pos := p.basicMatch(item, withPos, slab)
 	if sidx := offset[0]; sidx >= 0 {
 		offsets := []Offset{offset}
-		result := buildResult(item, offsets, bonus)
-		return &result, offsets, pos
+		return buildResult(item, offsets, bonus), offsets, pos
 	}
-	return nil, nil, nil
+	return Result{}, nil, nil
 }
 
 func (p *Pattern) basicMatch(item *Item, withPos bool, slab *util.Slab) (Offset, int, *[]int) {

src/pattern_test.go

@@ -2,6 +2,7 @@ package fzf
 
 import (
 	"reflect"
+	"runtime"
 	"testing"
 
 	"github.com/junegunn/fzf/src/algo"
@@ -68,7 +69,7 @@ func buildPattern(fuzzy bool, fuzzyAlgo algo.Algo, extended bool, caseMode Case,
 	withPos bool, cacheable bool, nth []Range, delimiter Delimiter, runes []rune) *Pattern {
 	return BuildPattern(NewChunkCache(), make(map[string]*Pattern),
 		fuzzy, fuzzyAlgo, extended, caseMode, normalize, forward,
-		withPos, cacheable, nth, delimiter, revision{}, runes, nil)
+		withPos, cacheable, nth, delimiter, revision{}, runes, nil, 0)
 }
 
 func TestExact(t *testing.T) {
@@ -137,7 +138,7 @@ func TestOrigTextAndTransformed(t *testing.T) {
 			origText:    &origBytes,
 			transformed: &transformed{pattern.revision, trans}}
 		pattern.extended = extended
-		matches := pattern.matchChunk(&chunk, nil, slab) // No cache
+		matches, _ := pattern.matchChunk(&chunk, nil, slab) // No cache
 		if !(matches[0].item.text.ToString() == "junegunn" &&
 			string(*matches[0].item.origText) == "junegunn.choi" &&
 			reflect.DeepEqual((*matches[0].item.transformed).tokens, trans)) {
@@ -199,3 +200,119 @@ func TestCacheable(t *testing.T) {
 	test(false, "foo 'bar", "foo", false)
 	test(false, "foo !bar", "foo", false)
 }
+
+func buildChunks(numChunks int) []*Chunk {
+	chunks := make([]*Chunk, numChunks)
+	words := []string{
+		"src/main/java/com/example/service/UserService.java",
+		"src/test/java/com/example/service/UserServiceTest.java",
+		"docs/api/reference/endpoints.md",
+		"lib/internal/utils/string_helper.go",
+		"pkg/server/http/handler/auth.go",
+		"build/output/release/app.exe",
+		"config/production/database.yml",
+		"scripts/deploy/kubernetes/setup.sh",
+		"vendor/github.com/junegunn/fzf/src/core.go",
+		"node_modules/.cache/babel/transform.js",
+	}
+	for ci := range numChunks {
+		chunks[ci] = &Chunk{count: chunkSize}
+		for i := range chunkSize {
+			text := words[(ci*chunkSize+i)%len(words)]
+			chunks[ci].items[i] = Item{text: util.ToChars([]byte(text))}
+			chunks[ci].items[i].text.Index = int32(ci*chunkSize + i)
+		}
+	}
+	return chunks
+}
+
+func buildPatternWith(cache *ChunkCache, runes []rune) *Pattern {
+	return BuildPattern(cache, make(map[string]*Pattern),
+		true, algo.FuzzyMatchV2, true, CaseSmart, false, true,
+		false, true, []Range{}, Delimiter{}, revision{}, runes, nil, 0)
+}
+
+func TestBitmapCacheBenefit(t *testing.T) {
+	numChunks := 100
+	chunks := buildChunks(numChunks)
+	queries := []string{"s", "se", "ser", "serv", "servi"}
+
+	// 1. Run all queries with shared cache (simulates incremental typing)
+	cache := NewChunkCache()
+	for _, q := range queries {
+		pat := buildPatternWith(cache, []rune(q))
+		for _, chunk := range chunks {
+			pat.Match(chunk, slab)
+		}
+	}
+
+	// 2. GC and measure memory with cache populated
+	runtime.GC()
+	runtime.GC()
+	var memWith runtime.MemStats
+	runtime.ReadMemStats(&memWith)
+
+	// 3. Clear cache, GC, measure again
+	cache.Clear()
+	runtime.GC()
+	runtime.GC()
+	var memWithout runtime.MemStats
+	runtime.ReadMemStats(&memWithout)
+
+	cacheMem := int64(memWith.Alloc) - int64(memWithout.Alloc)
+	t.Logf("Chunks: %d, Queries: %d", numChunks, len(queries))
+	t.Logf("Cache memory: %d bytes (%.1f KB)", cacheMem, float64(cacheMem)/1024)
+	t.Logf("Per-chunk-per-query: %.0f bytes", float64(cacheMem)/float64(numChunks*len(queries)))
+
+	// 4. Verify correctness: cached vs uncached produce same results
+	cache2 := NewChunkCache()
+	for _, q := range queries {
+		pat := buildPatternWith(cache2, []rune(q))
+		for _, chunk := range chunks {
+			pat.Match(chunk, slab)
+		}
+	}
+	for _, q := range queries {
+		patCached := buildPatternWith(cache2, []rune(q))
+		patFresh := buildPatternWith(NewChunkCache(), []rune(q))
+		var countCached, countFresh int
+		for _, chunk := range chunks {
+			countCached += len(patCached.Match(chunk, slab))
+			countFresh += len(patFresh.Match(chunk, slab))
+		}
+		if countCached != countFresh {
+			t.Errorf("query=%q: cached=%d, fresh=%d", q, countCached, countFresh)
+		}
+		t.Logf("query=%q: matches=%d", q, countCached)
+	}
+}
+
+func BenchmarkWithCache(b *testing.B) {
+	numChunks := 100
+	chunks := buildChunks(numChunks)
+	queries := []string{"s", "se", "ser", "serv", "servi"}
+
+	b.Run("cached", func(b *testing.B) {
+		for range b.N {
+			cache := NewChunkCache()
+			for _, q := range queries {
+				pat := buildPatternWith(cache, []rune(q))
+				for _, chunk := range chunks {
+					pat.Match(chunk, slab)
+				}
+			}
+		}
+	})
+
+	b.Run("uncached", func(b *testing.B) {
+		for range b.N {
+			for _, q := range queries {
+				cache := NewChunkCache()
+				pat := buildPatternWith(cache, []rune(q))
+				for _, chunk := range chunks {
+					pat.Match(chunk, slab)
+				}
+			}
+		}
+	})
+}

src/protector/protector_openbsd.go

@@ -6,5 +6,5 @@ import "golang.org/x/sys/unix"
 
 // Protect calls OS specific protections like pledge on OpenBSD
 func Protect() {
-	unix.PledgePromises("stdio dpath wpath rpath tty proc exec inet tmppath")
+	unix.PledgePromises("stdio cpath dpath wpath rpath inet fattr unix tty proc exec")
 }

src/proxy.go

@@ -23,6 +23,32 @@ func escapeSingleQuote(str string) string {
 	return "'" + strings.ReplaceAll(str, "'", "'\\''") + "'"
 }
 
+func popupArgStr(args []string, opts *Options) (string, string) {
+	fzf, rest := args[0], args[1:]
+	args = []string{"--bind=ctrl-z:ignore"}
+	if !opts.Tmux.border && (opts.BorderShape == tui.BorderUndefined || opts.BorderShape == tui.BorderLine) {
+		if tui.DefaultBorderShape == tui.BorderRounded {
+			rest = append(rest, "--border=rounded")
+		} else {
+			rest = append(rest, "--border=sharp")
+		}
+	}
+	if opts.Tmux.border && opts.Margin == defaultMargin() {
+		args = append(args, "--margin=0,1")
+	}
+	argStr := escapeSingleQuote(fzf)
+	for _, arg := range append(args, rest...) {
+		argStr += " " + escapeSingleQuote(arg)
+	}
+	argStr += ` --no-popup --no-height`
+
+	dir, err := os.Getwd()
+	if err != nil {
+		dir = "."
+	}
+	return argStr, dir
+}
+
 func fifo(name string) (string, error) {
 	ns := time.Now().UnixNano()
 	output := filepath.Join(os.TempDir(), fmt.Sprintf("fzf-%s-%d", name, ns))

src/reader.go

@@ -274,6 +274,24 @@ func (r *Reader) readFiles(roots []string, opts walkerOpts, ignores []string) bo
 		ToSlash: fastwalk.DefaultToSlash(),
 		Sort:    fastwalk.SortFilesFirst,
 	}
+
+	// When following symlinks, precompute the absolute real paths of walker
+	// roots so we can skip symlinks that point to an ancestor. fastwalk's
+	// built-in loop detection (shouldTraverse) catches loops on the second
+	// pass, but a single pass through a symlink like z: -> / already
+	// traverses the entire root filesystem, causing severe resource
+	// exhaustion. Skipping ancestor symlinks prevents this entirely.
+	var absRoots []string
+	if opts.follow {
+		for _, root := range roots {
+			if real, err := filepath.EvalSymlinks(root); err == nil {
+				if abs, err := filepath.Abs(real); err == nil {
+					absRoots = append(absRoots, filepath.Clean(abs))
+				}
+			}
+		}
+	}
+
 	ignoresBase := []string{}
 	ignoresFull := []string{}
 	ignoresSuffix := []string{}
@@ -307,6 +325,24 @@ func (r *Reader) readFiles(roots []string, opts walkerOpts, ignores []string) bo
 			if isDirSymlink && !opts.follow {
 				return filepath.SkipDir
 			}
+			// Skip symlinks whose target is an ancestor of (or equal to)
+			// any walker root. Following such symlinks would traverse a
+			// superset of the tree we're already walking.
+			if isDirSymlink && len(absRoots) > 0 {
+				if target, err := filepath.EvalSymlinks(path); err == nil {
+					if abs, err := filepath.Abs(target); err == nil {
+						abs = filepath.Clean(abs)
+						if abs == string(os.PathSeparator) {
+							return filepath.SkipDir
+						}
+						for _, absRoot := range absRoots {
+							if absRoot == abs || strings.HasPrefix(absRoot, abs+string(os.PathSeparator)) {
+								return filepath.SkipDir
+							}
+						}
+					}
+				}
+			}
 			isDir := de.IsDir() || isDirSymlink
 			if isDir {
 				base := filepath.Base(path)

src/result.go

@@ -33,8 +33,6 @@ func buildResult(item *Item, offsets []Offset, score int) Result {
 		sort.Sort(ByOrder(offsets))
 	}
 
-	result := Result{item: item}
-	numChars := item.text.Length()
 	minBegin := math.MaxUint16
 	minEnd := math.MaxUint16
 	maxEnd := 0
@@ -49,6 +47,14 @@ func buildResult(item *Item, offsets []Offset, score int) Result {
 		}
 	}
 
+	return buildResultFromBounds(item, score, minBegin, minEnd, maxEnd, validOffsetFound)
+}
+
+// buildResultFromBounds builds a Result from pre-computed offset bounds.
+func buildResultFromBounds(item *Item, score int, minBegin, minEnd, maxEnd int, validOffsetFound bool) Result {
+	result := Result{item: item}
+	numChars := item.text.Length()
+
 	for idx, criterion := range sortCriteria {
 		val := uint16(math.MaxUint16)
 		switch criterion {
@@ -75,7 +81,6 @@ func buildResult(item *Item, offsets []Offset, score int) Result {
 			val = item.TrimLength()
 		case byPathname:
 			if validOffsetFound {
-				// lastDelim := strings.LastIndexByte(item.text.ToString(), '/')
 				lastDelim := -1
 				s := item.text.ToString()
 				for i := len(s) - 1; i >= 0; i-- {
@@ -123,7 +128,7 @@ func minRank() Result {
 	return Result{item: &minItem, points: [4]uint16{math.MaxUint16, 0, 0, 0}}
 }
 
-func (result *Result) colorOffsets(matchOffsets []Offset, nthOffsets []Offset, theme *tui.ColorTheme, colBase tui.ColorPair, colMatch tui.ColorPair, attrNth tui.Attr, hidden bool) []colorOffset {
+func (result *Result) colorOffsets(matchOffsets []Offset, nthOffsets []Offset, theme *tui.ColorTheme, colBase tui.ColorPair, colMatch tui.ColorPair, attrNth tui.Attr, nthOverlay tui.Attr, hidden bool) []colorOffset {
 	itemColors := result.item.Colors()
 
 	// No ANSI codes
@@ -208,6 +213,10 @@ func (result *Result) colorOffsets(matchOffsets []Offset, nthOffsets []Offset, t
 		}
 		return tui.NewColorPair(fg, bg, ansi.color.attr).WithUl(ansi.color.ul).MergeAttr(base)
 	}
+	fgAttr := tui.ColNormal.Attr()
+	nthAttrFinal := fgAttr.Merge(attrNth).Merge(nthOverlay)
+	nthBase := colBase.WithNewAttr(nthAttrFinal)
+
 	var colors []colorOffset
 	add := func(idx int) {
 		if curr.fbg >= 0 {
@@ -221,7 +230,7 @@ func (result *Result) colorOffsets(matchOffsets []Offset, nthOffsets []Offset, t
 			if curr.match {
 				var color tui.ColorPair
 				if curr.nth {
-					color = colBase.WithAttr(attrNth).Merge(colMatch)
+					color = nthBase.Merge(colMatch)
 				} else {
 					color = colBase.Merge(colMatch)
 				}
@@ -241,7 +250,7 @@ func (result *Result) colorOffsets(matchOffsets []Offset, nthOffsets []Offset, t
 					if color.Fg().IsDefault() && origColor.HasBg() {
 						color = origColor
 						if curr.nth {
-							color = color.WithAttr(attrNth &^ tui.AttrRegular)
+							color = color.WithAttr((attrNth &^ tui.AttrRegular).Merge(nthOverlay))
 						}
 					} else {
 						color = origColor.MergeNonDefault(color)
@@ -253,7 +262,7 @@ func (result *Result) colorOffsets(matchOffsets []Offset, nthOffsets []Offset, t
 				ansi := itemColors[curr.index]
 				base := colBase
 				if curr.nth {
-					base = base.WithAttr(attrNth)
+					base = nthBase
 				}
 				if hidden {
 					base = base.WithFg(theme.Nomatch)
@@ -265,7 +274,7 @@ func (result *Result) colorOffsets(matchOffsets []Offset, nthOffsets []Offset, t
 					match:  false,
 					url:    ansi.color.url})
 			} else {
-				color := colBase.WithAttr(attrNth)
+				color := nthBase
 				if hidden {
 					color = color.WithFg(theme.Nomatch)
 				}
@@ -334,3 +343,79 @@ func (a ByRelevanceTac) Swap(i, j int) {
 func (a ByRelevanceTac) Less(i, j int) bool {
 	return compareRanks(a[i], a[j], true)
 }
+
+// radixSortResults sorts Results by their points key using LSD radix sort.
+// O(n) time complexity vs O(n log n) for comparison sort.
+// The sort is stable, so equal-key items maintain original (item-index) order.
+// For tac mode, runs of equal keys are reversed after sorting.
+func radixSortResults(a []Result, tac bool, scratch []Result) []Result {
+	n := len(a)
+	if n < 128 {
+		if tac {
+			sort.Sort(ByRelevanceTac(a))
+		} else {
+			sort.Sort(ByRelevance(a))
+		}
+		return scratch[:0]
+	}
+
+	if cap(scratch) < n {
+		scratch = make([]Result, n)
+	}
+	buf := scratch[:n]
+	src, dst := a, buf
+	scattered := 0
+
+	for pass := range 8 {
+		shift := uint(pass) * 8
+
+		var count [256]int
+		for i := range src {
+			count[byte(sortKey(&src[i])>>shift)]++
+		}
+
+		// Skip if all items have the same byte value at this position
+		if count[byte(sortKey(&src[0])>>shift)] == n {
+			continue
+		}
+
+		var offset [256]int
+		for i := 1; i < 256; i++ {
+			offset[i] = offset[i-1] + count[i-1]
+		}
+
+		for i := range src {
+			b := byte(sortKey(&src[i]) >> shift)
+			dst[offset[b]] = src[i]
+			offset[b]++
+		}
+
+		src, dst = dst, src
+		scattered++
+	}
+
+	// If odd number of scatters, data is in buf, copy back to a
+	if scattered%2 == 1 {
+		copy(a, src)
+	}
+
+	// Handle tac: reverse runs of equal keys so equal-key items
+	// are in reverse item-index order
+	if tac {
+		i := 0
+		for i < n {
+			ki := sortKey(&a[i])
+			j := i + 1
+			for j < n && sortKey(&a[j]) == ki {
+				j++
+			}
+			if j-i > 1 {
+				for l, r := i, j-1; l < r; l, r = l+1, r-1 {
+					a[l], a[r] = a[r], a[l]
+				}
+			}
+			i = j
+		}
+	}
+	return scratch
+}

src/result_others.go

@@ -1,4 +1,4 @@
-//go:build !386 && !amd64
+//go:build !386 && !amd64 && !arm64
 
 package fzf
 
@@ -14,3 +14,7 @@ func compareRanks(irank Result, jrank Result, tac bool) bool {
 	}
 	return (irank.item.Index() <= jrank.item.Index()) != tac
 }
+
+func sortKey(r *Result) uint64 {
+	return uint64(r.points[0]) | uint64(r.points[1])<<16 | uint64(r.points[2])<<32 | uint64(r.points[3])<<48
+}

src/result_test.go

@@ -2,6 +2,7 @@ package fzf
 
 import (
 	"math"
+	"math/rand"
 	"sort"
 	"testing"
 
@@ -131,7 +132,7 @@ func TestColorOffset(t *testing.T) {
 
 	colBase := tui.NewColorPair(89, 189, tui.AttrUndefined)
 	colMatch := tui.NewColorPair(99, 199, tui.AttrUndefined)
-	colors := item.colorOffsets(offsets, nil, tui.Dark256, colBase, colMatch, tui.AttrUndefined, false)
+	colors := item.colorOffsets(offsets, nil, tui.Dark256, colBase, colMatch, tui.AttrUndefined, 0, false)
 	assert := func(idx int, b int32, e int32, c tui.ColorPair) {
 		o := colors[idx]
 		if o.offset[0] != b || o.offset[1] != e || o.color != c {
@@ -158,7 +159,7 @@ func TestColorOffset(t *testing.T) {
 
 	nthOffsets := []Offset{{37, 39}, {42, 45}}
 	for _, attr := range []tui.Attr{tui.AttrRegular, tui.StrikeThrough} {
-		colors = item.colorOffsets(offsets, nthOffsets, tui.Dark256, colRegular, colUnderline, attr, false)
+		colors = item.colorOffsets(offsets, nthOffsets, tui.Dark256, colRegular, colUnderline, attr, 0, false)
 
 		// [{[0 5] {1 5 0}} {[5 15] {1 5 8}} {[15 20] {1 5 0}}
 		//  {[22 25] {2 6 1}} {[25 27] {2 6 9}} {[27 30] {-1 -1 8}}
@@ -181,4 +182,92 @@ func TestColorOffset(t *testing.T) {
 		assert(10, 37, 39, tui.NewColorPair(4, 8, expected))
 		assert(11, 39, 40, tui.NewColorPair(4, 8, tui.Bold))
 	}
+
+	// Test nthOverlay: simulates nth:regular with current-fg:underline
+	// The overlay (underline) should survive even though nth:regular clears attrs.
+	// Precedence: fg < nth < current-fg
+	colors = item.colorOffsets(offsets, nthOffsets, tui.Dark256, colRegular, colUnderline, tui.AttrRegular, tui.Underline, false)
+
+	// nth regions should have Underline (from overlay), not cleared by AttrRegular
+	// Non-nth regions keep colBase attrs (AttrUndefined)
+	assert(0, 0, 5, tui.NewColorPair(1, 5, tui.AttrUndefined))
+	assert(1, 5, 15, tui.NewColorPair(1, 5, tui.Underline))
+	assert(2, 15, 20, tui.NewColorPair(1, 5, tui.AttrUndefined))
+	assert(3, 22, 25, tui.NewColorPair(2, 6, tui.Bold))
+	assert(4, 25, 27, tui.NewColorPair(2, 6, tui.Bold|tui.Underline))
+	assert(5, 27, 30, colUnderline)
+	assert(6, 30, 32, tui.NewColorPair(3, 7, tui.Underline))
+	assert(7, 32, 33, colUnderline)
+	assert(8, 33, 35, tui.NewColorPair(4, 8, tui.Bold|tui.Underline))
+	assert(9, 35, 37, tui.NewColorPair(4, 8, tui.Bold))
+	// nth region within ANSI bold: AttrRegular clears, overlay adds Underline back
+	assert(10, 37, 39, tui.NewColorPair(4, 8, tui.Bold|tui.Underline))
+	assert(11, 39, 40, tui.NewColorPair(4, 8, tui.Bold))
+
+	// Test nthOverlay with additive attrs: nth:strikethrough with selected-fg:bold
+	colors = item.colorOffsets(offsets, nthOffsets, tui.Dark256, colRegular, colUnderline, tui.StrikeThrough, tui.Bold, false)
+
+	// Non-nth entries unchanged from overlay=0 case
+	assert(0, 0, 5, tui.NewColorPair(1, 5, tui.AttrUndefined))
+	assert(5, 27, 30, colUnderline) // match only, no nth
+	assert(7, 32, 33, colUnderline) // match only, no nth
+	// nth region within ANSI bold: StrikeThrough|Bold merged with ANSI Bold
+	assert(10, 37, 39, tui.NewColorPair(4, 8, tui.Bold|tui.StrikeThrough))
+}
+
+func TestRadixSortResults(t *testing.T) {
+	sortCriteria = []criterion{byScore, byLength}
+
+	rng := rand.New(rand.NewSource(42))
+
+	for _, n := range []int{128, 256, 500, 1000} {
+		for _, tac := range []bool{false, true} {
+			// Build items with random points and indices
+			items := make([]*Item, n)
+			for i := range items {
+				items[i] = &Item{text: util.Chars{Index: int32(i)}}
+			}
+
+			results := make([]Result, n)
+			for i := range results {
+				results[i] = Result{
+					item: items[i],
+					points: [4]uint16{
+						uint16(rng.Intn(256)),
+						uint16(rng.Intn(256)),
+						uint16(rng.Intn(256)),
+						uint16(rng.Intn(256)),
+					},
+				}
+			}
+
+			// Make some duplicates to test stability
+			for i := 0; i < n/4; i++ {
+				j := rng.Intn(n)
+				k := rng.Intn(n)
+				results[j].points = results[k].points
+			}
+
+			// Copy for reference sort
+			expected := make([]Result, n)
+			copy(expected, results)
+			if tac {
+				sort.Sort(ByRelevanceTac(expected))
+			} else {
+				sort.Sort(ByRelevance(expected))
+			}
+
+			// Radix sort
+			var scratch []Result
+			scratch = radixSortResults(results, tac, scratch)
+
+			for i := range results {
+				if results[i] != expected[i] {
+					t.Errorf("n=%d tac=%v: mismatch at index %d: got item %d, want item %d",
+						n, tac, i, results[i].item.Index(), expected[i].item.Index())
+					break
+				}
+			}
+		}
+	}
 }

src/result_x86.go

@@ -1,4 +1,4 @@
-//go:build 386 || amd64
+//go:build 386 || amd64 || arm64
 
 package fzf
 
@@ -14,3 +14,7 @@ func compareRanks(irank Result, jrank Result, tac bool) bool {
 	}
 	return (irank.item.Index() <= jrank.item.Index()) != tac
 }
+
+func sortKey(r *Result) uint64 {
+	return *(*uint64)(unsafe.Pointer(&r.points[0]))
+}

src/terminal.go

@@ -216,8 +216,9 @@ const (
 )
 
 type StatusItem struct {
-	Index int    `json:"index"`
-	Text  string `json:"text"`
+	Index     int    `json:"index"`
+	Text      string `json:"text"`
+	Positions []int  `json:"positions,omitempty"`
 }
 
 type Status struct {
@@ -314,6 +315,13 @@ type Terminal struct {
 	sort                 bool
 	toggleSort           bool
 	track                trackOption
+	idNth                []Range
+	trackKey             string
+	trackBlocked         bool
+	trackSync            bool
+	trackKeyCache        map[int32]bool
+	pendingSelections    map[string]selectedItem
+	targetIndex          int32
 	delimiter            Delimiter
 	expect               map[tui.Event]string
 	keymap               map[tui.Event][]*action
@@ -327,7 +335,7 @@ type Terminal struct {
 	headerVisible        bool
 	headerFirst          bool
 	headerLines          int
-	header               []string
+	header               []Item
 	header0              []string
 	footer               []string
 	ellipsis             string
@@ -339,6 +347,9 @@ type Terminal struct {
 	nthAttr              tui.Attr
 	nth                  []Range
 	nthCurrent           []Range
+	withNthDefault       string
+	withNthExpr          string
+	withNthEnabled       bool
 	acceptNth            func([]Token, int32) string
 	tabstop              int
 	margin               [4]sizeSpec
@@ -383,6 +394,8 @@ type Terminal struct {
 	hasLoadActions       bool
 	hasResizeActions     bool
 	triggerLoad          bool
+	pendingReqList       bool
+	filterSelection      bool
 	reading              bool
 	running              *util.AtomicBool
 	failed               *string
@@ -542,6 +555,7 @@ const (
 	actChangeBorderLabel
 	actChangeGhost
 	actChangeHeader
+	actChangeHeaderLines
 	actChangeFooter
 	actChangeHeaderLabel
 	actChangeFooterLabel
@@ -549,6 +563,7 @@ const (
 	actChangeListLabel
 	actChangeMulti
 	actChangeNth
+	actChangeWithNth
 	actChangePointer
 	actChangePreview
 	actChangePreviewLabel
@@ -627,12 +642,14 @@ const (
 	actTransformBorderLabel
 	actTransformGhost
 	actTransformHeader
+	actTransformHeaderLines
 	actTransformFooter
 	actTransformHeaderLabel
 	actTransformFooterLabel
 	actTransformInputLabel
 	actTransformListLabel
 	actTransformNth
+	actTransformWithNth
 	actTransformPointer
 	actTransformPreviewLabel
 	actTransformPrompt
@@ -645,12 +662,14 @@ const (
 	actBgTransformBorderLabel
 	actBgTransformGhost
 	actBgTransformHeader
+	actBgTransformHeaderLines
 	actBgTransformFooter
 	actBgTransformHeaderLabel
 	actBgTransformFooterLabel
 	actBgTransformInputLabel
 	actBgTransformListLabel
 	actBgTransformNth
+	actBgTransformWithNth
 	actBgTransformPointer
 	actBgTransformPreviewLabel
 	actBgTransformPrompt
@@ -710,12 +729,14 @@ func processExecution(action actionType) bool {
 		actTransformBorderLabel,
 		actTransformGhost,
 		actTransformHeader,
+		actTransformHeaderLines,
 		actTransformFooter,
 		actTransformHeaderLabel,
 		actTransformFooterLabel,
 		actTransformInputLabel,
 		actTransformListLabel,
 		actTransformNth,
+		actTransformWithNth,
 		actTransformPointer,
 		actTransformPreviewLabel,
 		actTransformPrompt,
@@ -725,12 +746,14 @@ func processExecution(action actionType) bool {
 		actBgTransformBorderLabel,
 		actBgTransformGhost,
 		actBgTransformHeader,
+		actBgTransformHeaderLines,
 		actBgTransformFooter,
 		actBgTransformHeaderLabel,
 		actBgTransformFooterLabel,
 		actBgTransformInputLabel,
 		actBgTransformListLabel,
 		actBgTransformNth,
+		actBgTransformWithNth,
 		actBgTransformPointer,
 		actBgTransformPreviewLabel,
 		actBgTransformPrompt,
@@ -760,15 +783,21 @@ type placeholderFlags struct {
 	raw           bool
 }
 
+type withNthSpec struct {
+	fn func([]Token, int32) string // nil = clear (restore original)
+}
+
 type searchRequest struct {
-	sort     bool
-	sync     bool
-	nth      *[]Range
-	command  *commandSpec
-	environ  []string
-	changed  bool
-	denylist []int32
-	revision revision
+	sort        bool
+	sync        bool
+	nth         *[]Range
+	withNth     *withNthSpec
+	headerLines *int
+	command     *commandSpec
+	environ     []string
+	changed     bool
+	denylist    []int32
+	revision    revision
 }
 
 type previewRequest struct {
@@ -1022,6 +1051,8 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 		sort:               opts.Sort > 0,
 		toggleSort:         opts.ToggleSort,
 		track:              opts.Track,
+		idNth:              opts.IdNth,
+		targetIndex:        minItem.Index(),
 		delimiter:          opts.Delimiter,
 		expect:             opts.Expect,
 		keymap:             opts.Keymap,
@@ -1063,7 +1094,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 		headerFirst:        opts.HeaderFirst,
 		headerLines:        opts.HeaderLines,
 		gap:                opts.Gap,
-		header:             []string{},
+		header:             []Item{},
 		footer:             opts.Footer,
 		header0:            opts.Header,
 		ansi:               opts.Ansi,
@@ -1072,6 +1103,9 @@ func NewTerminal(opts *Options, eventBox *util.EventBox, executor *util.Executor
 		nthAttr:            opts.Theme.Nth.Attr,
 		nth:                opts.Nth,
 		nthCurrent:         opts.Nth,
+		withNthDefault:     opts.WithNthExpr,
+		withNthExpr:        opts.WithNthExpr,
+		withNthEnabled:     opts.WithNth != nil,
 		tabstop:            opts.Tabstop,
 		raw:                opts.Raw,
 		hasStartActions:    false,
@@ -1343,6 +1377,9 @@ func (t *Terminal) environImpl(forPreview bool) []string {
 	if len(t.nthCurrent) > 0 {
 		env = append(env, "FZF_NTH="+RangesToString(t.nthCurrent))
 	}
+	if len(t.withNthExpr) > 0 {
+		env = append(env, "FZF_WITH_NTH="+t.withNthExpr)
+	}
 	if t.raw {
 		val := "0"
 		if t.isCurrentItemMatch() {
@@ -1526,7 +1563,7 @@ func (t *Terminal) ansiLabelPrinter(str string, color *tui.ColorPair, fill bool)
 	printFn := func(window tui.Window, limit int) {
 		if offsets == nil {
 			// tui.Col* are not initialized until renderer.Init()
-			offsets = result.colorOffsets(nil, nil, t.theme, *color, *color, t.nthAttr, false)
+			offsets = result.colorOffsets(nil, nil, t.theme, *color, *color, t.nthAttr, 0, false)
 		}
 		for limit > 0 {
 			if length > limit {
@@ -1589,7 +1626,7 @@ func (t *Terminal) parsePrompt(prompt string) (func(), int) {
 				return 1
 			}
 			t.printHighlighted(
-				Result{item: item}, tui.ColPrompt, tui.ColPrompt, false, false, false, line, line, true, preTask, nil)
+				Result{item: item}, tui.ColPrompt, tui.ColPrompt, false, false, false, line, line, true, preTask, nil, 0)
 		})
 		t.wrap = wrap
 	}
@@ -1712,6 +1749,17 @@ func (t *Terminal) Input() (bool, []rune) {
 	return paused, copySlice(src)
 }
 
+// PauseRendering blocks the terminal from reading items.
+// Must be paired with ResumeRendering.
+func (t *Terminal) PauseRendering() {
+	t.mutex.Lock()
+}
+
+// ResumeRendering releases the lock acquired by PauseRendering.
+func (t *Terminal) ResumeRendering() {
+	t.mutex.Unlock()
+}
+
 // UpdateCount updates the count information
 func (t *Terminal) UpdateCount(cnt int, final bool, failedCommand *string) {
 	t.mutex.Lock()
@@ -1755,8 +1803,14 @@ func (t *Terminal) changeFooter(footer string) {
 }
 
 // UpdateHeader updates the header
-func (t *Terminal) UpdateHeader(header []string) {
+func (t *Terminal) UpdateHeader(header []Item) {
 	t.mutex.Lock()
+	// Pad to t.headerLines so that click coordinate mapping works correctly
+	if len(header) < t.headerLines {
+		padded := make([]Item, t.headerLines)
+		copy(padded, header)
+		header = padded
+	}
 	t.header = header
 	t.mutex.Unlock()
 	t.reqBox.Set(reqHeader, nil)
@@ -1788,6 +1842,10 @@ func (t *Terminal) UpdateList(result MatchResult) {
 			prevIndex = merger.First().item.Index()
 		}
 	}
+	if t.targetIndex != minItem.Index() {
+		prevIndex = t.targetIndex
+		t.targetIndex = minItem.Index()
+	}
 	t.progress = 100
 	t.merger = merger
 	t.resultMerger = merger
@@ -1801,7 +1859,14 @@ func (t *Terminal) UpdateList(result MatchResult) {
 	}
 	if t.revision != newRevision {
 		if !t.revision.compatible(newRevision) {
-			// Reloaded: clear selection
+			// Reloaded: capture selection keys for restoration, then clear (reload-sync only)
+			if t.trackSync && len(t.idNth) > 0 && t.multi > 0 && len(t.selected) > 0 {
+				t.pendingSelections = make(map[string]selectedItem, len(t.selected))
+				for _, sel := range t.selected {
+					key := t.trackKeyFor(sel.item, t.idNth)
+					t.pendingSelections[key] = sel
+				}
+			}
 			t.selected = make(map[int32]selectedItem)
 			t.clearNumLinesCache()
 		} else {
@@ -1824,12 +1889,54 @@ func (t *Terminal) UpdateList(result MatchResult) {
 		}
 		t.revision = newRevision
 		t.version++
+
+		// Filter out selections that no longer match after with-nth change.
+		// Must be inside the revision check so we don't consume the flag
+		// on a stale EvtSearchFin from a previous search.
+		if t.filterSelection && t.multi > 0 && len(t.selected) > 0 {
+			matchMap := t.resultMerger.ToMap()
+			filtered := make(map[int32]selectedItem)
+			for k, v := range t.selected {
+				if _, matched := matchMap[k]; matched {
+					filtered[k] = v
+				}
+			}
+			t.selected = filtered
+		}
+		t.filterSelection = false
 	}
 	if t.triggerLoad {
 		t.triggerLoad = false
+		t.pendingReqList = true
 		t.eventChan <- tui.Load.AsEvent()
 	}
-	if prevIndex >= 0 {
+	// Search for the tracked item by nth key
+	// - reload (async): search eagerly, unblock as soon as match is found
+	// - reload-sync: wait until stream is complete before searching
+	trackWasBlocked := t.trackBlocked
+	if len(t.trackKey) > 0 && (!t.trackSync || !t.reading) {
+		found := false
+		for i := 0; i < t.merger.Length(); i++ {
+			item := t.merger.Get(i).item
+			idx := item.Index()
+			match, ok := t.trackKeyCache[idx]
+			if !ok {
+				match = t.trackKeyFor(item, t.idNth) == t.trackKey
+				t.trackKeyCache[idx] = match
+			}
+			if match {
+				t.cy = i
+				if t.track.Current() {
+					t.track.index = idx
+				}
+				found = true
+				break
+			}
+		}
+		if found || !t.reading {
+			t.unblockTrack()
+		}
+	} else if prevIndex >= 0 {
 		pos := t.cy - t.offset
 		count := t.merger.Length()
 		i := t.merger.FindIndex(prevIndex)
@@ -1845,12 +1952,25 @@ func (t *Terminal) UpdateList(result MatchResult) {
 			t.cy = count - min(count, t.maxItems()) + pos
 		}
 	}
+	// Restore selections by id-nth key after reload completes
+	if !t.reading && t.pendingSelections != nil {
+		for i := 0; i < t.merger.Length() && len(t.pendingSelections) > 0; i++ {
+			item := t.merger.Get(i).item
+			key := t.trackKeyFor(item, t.idNth)
+			if sel, found := t.pendingSelections[key]; found {
+				t.selected[item.Index()] = selectedItem{sel.at, item}
+				delete(t.pendingSelections, key)
+			}
+		}
+		t.pendingSelections = nil
+	}
 	needActivation := false
 	if !t.reading {
 		switch t.resultMerger.Length() {
 		case 0:
 			zero := tui.Zero.AsEvent()
 			if _, prs := t.keymap[zero]; prs {
+				t.pendingReqList = true
 				t.eventChan <- zero
 			}
 			// --sync, only 'focus' is bound, but no items to focus
@@ -1858,16 +1978,26 @@ func (t *Terminal) UpdateList(result MatchResult) {
 		case 1:
 			one := tui.One.AsEvent()
 			if _, prs := t.keymap[one]; prs {
+				t.pendingReqList = true
 				t.eventChan <- one
 			}
 		}
 	}
 	if t.hasResultActions {
+		t.pendingReqList = true
 		t.eventChan <- tui.Result.AsEvent()
 	}
+	updateList := !t.trackBlocked && !t.pendingReqList
+	updatePrompt := trackWasBlocked && !t.trackBlocked
 	t.mutex.Unlock()
+
 	t.reqBox.Set(reqInfo, nil)
-	t.reqBox.Set(reqList, nil)
+	if updateList {
+		t.reqBox.Set(reqList, nil)
+	}
+	if updatePrompt {
+		t.reqBox.Set(reqPrompt, nil)
+	}
 	if needActivation {
 		t.reqBox.Set(reqActivate, nil)
 	}
@@ -2113,7 +2243,7 @@ func (t *Terminal) resizeWindows(forcePreview bool, redrawBorder bool) {
 	width := screenWidth - marginInt[1] - marginInt[3]
 	height := screenHeight - marginInt[0] - marginInt[2]
 
-	t.prevLines = make([]itemLine, screenHeight)
+	t.prevLines = make([]itemLine, max(1, screenHeight))
 	if t.border != nil && redrawBorder {
 		t.border = nil
 	}
@@ -2816,6 +2946,8 @@ func (t *Terminal) printPrompt() {
 	color := tui.ColInput
 	if t.paused {
 		color = tui.ColDisabled
+	} else if t.trackBlocked {
+		color = color.WithAttr(tui.Dim)
 	}
 	w.CPrint(color, string(before))
 	w.CPrint(color, string(after))
@@ -2899,18 +3031,6 @@ func (t *Terminal) printInfoImpl() {
 	found := t.resultMerger.Length()
 	total := max(found, t.count)
 	output := fmt.Sprintf("%d/%d", found, total)
-	if t.toggleSort {
-		if t.sort {
-			output += " +S"
-		} else {
-			output += " -S"
-		}
-	}
-	if t.track.Global() {
-		output += " +T"
-	} else if t.track.Current() {
-		output += " +t"
-	}
 	if t.multi > 0 {
 		if t.multi == maxMulti {
 			output += fmt.Sprintf(" (%d)", len(t.selected))
@@ -2921,6 +3041,26 @@ func (t *Terminal) printInfoImpl() {
 	if t.progress > 0 && t.progress < 100 {
 		output += fmt.Sprintf(" (%d%%)", t.progress)
 	}
+	if t.toggleSort {
+		if t.sort {
+			output += " +S"
+		} else {
+			output += " -S"
+		}
+	}
+	if t.track.Global() {
+		if t.trackBlocked {
+			output += " +T*"
+		} else {
+			output += " +T"
+		}
+	} else if t.track.Current() {
+		if t.trackBlocked {
+			output += " +t*"
+		} else {
+			output += " +t"
+		}
+	}
 	if t.failed != nil && t.count == 0 {
 		output = fmt.Sprintf("[Command failed: %s]", *t.failed)
 	}
@@ -3079,11 +3219,11 @@ func (t *Terminal) printHeader() {
 	}
 
 	t.withWindow(t.headerWindow, func() {
-		var lines []string
+		var headerItems []Item
 		if !t.hasHeaderLinesWindow() {
-			lines = t.header
+			headerItems = t.header
 		}
-		t.printHeaderImpl(t.headerWindow, t.headerBorderShape, t.header0, lines)
+		t.printHeaderImpl(t.headerWindow, t.headerBorderShape, t.header0, headerItems)
 	})
 	if w, shape := t.determineHeaderLinesShape(); w {
 		t.withWindow(t.headerLinesWindow, func() {
@@ -3121,7 +3261,7 @@ func (t *Terminal) printFooter() {
 				func(markerClass) int {
 					t.footerWindow.Print(indent)
 					return indentSize
-				}, nil)
+				}, nil, 0)
 		}
 	})
 	t.wrap = wrap
@@ -3145,7 +3285,7 @@ func (t *Terminal) headerIndentImpl(base int, borderShape tui.BorderShape) int {
 	return indentSize
 }
 
-func (t *Terminal) printHeaderImpl(window tui.Window, borderShape tui.BorderShape, lines1 []string, lines2 []string) {
+func (t *Terminal) printHeaderImpl(window tui.Window, borderShape tui.BorderShape, lines1 []string, lines2 []Item) {
 	max := t.window.Height()
 	if !t.inputless && t.inputWindow == nil && window == nil && t.headerFirst {
 		max--
@@ -3172,7 +3312,8 @@ func (t *Terminal) printHeaderImpl(window tui.Window, borderShape tui.BorderShap
 	}
 	indent := strings.Repeat(" ", indentSize)
 	t.wrap = false
-	for idx, lineStr := range append(append([]string{}, lines1...), lines2...) {
+	totalLines := len(lines1) + len(lines2)
+	for idx := 0; idx < totalLines; idx++ {
 		line := idx
 		if needReverse && idx < len(lines1) {
 			line = len(lines1) - idx - 1
@@ -3186,18 +3327,25 @@ func (t *Terminal) printHeaderImpl(window tui.Window, borderShape tui.BorderShap
 		if line >= max {
 			continue
 		}
-		trimmed, colors, newState := extractColor(lineStr, state, nil)
-		state = newState
-		item := &Item{
-			text:   util.ToChars([]byte(trimmed)),
-			colors: colors}
+
+		var item *Item
+		if idx < len(lines1) {
+			trimmed, colors, newState := extractColor(lines1[idx], state, nil)
+			state = newState
+			item = &Item{
+				text:   util.ToChars([]byte(trimmed)),
+				colors: colors}
+		} else {
+			headerItem := lines2[idx-len(lines1)]
+			item = &headerItem
+		}
 
 		t.printHighlighted(Result{item: item},
 			tui.ColHeader, tui.ColHeader, false, false, false, line, line, true,
 			func(markerClass) int {
 				t.window.Print(indent)
 				return indentSize
-			}, nil)
+			}, nil, 0)
 	}
 	t.wrap = wrap
 }
@@ -3435,7 +3583,14 @@ func (t *Terminal) printItem(result Result, line int, maxLine int, index int, cu
 			}
 			return indentSize
 		}
-		finalLineNum = t.printHighlighted(result, tui.ColCurrent, tui.ColCurrentMatch, true, true, !matched, line, maxLine, forceRedraw, preTask, postTask)
+		colCurrent := tui.ColCurrent
+		nthOverlay := t.theme.NthCurrentAttr
+		if selected {
+			nthOverlay = t.theme.NthSelectedAttr.Merge(t.theme.NthCurrentAttr)
+			baseAttr := tui.ColNormal.Attr().Merge(t.theme.NthSelectedAttr).Merge(t.theme.NthCurrentAttr)
+			colCurrent = colCurrent.WithNewAttr(baseAttr)
+		}
+		finalLineNum = t.printHighlighted(result, colCurrent, tui.ColCurrentMatch, true, true, !matched, line, maxLine, forceRedraw, preTask, postTask, nthOverlay)
 	} else {
 		preTask := func(marker markerClass) int {
 			w := t.window.Width() - t.pointerLen
@@ -3469,7 +3624,11 @@ func (t *Terminal) printItem(result Result, line int, maxLine int, index int, cu
 			base = base.WithBg(altBg)
 			match = match.WithBg(altBg)
 		}
-		finalLineNum = t.printHighlighted(result, base, match, false, true, !matched, line, maxLine, forceRedraw, preTask, postTask)
+		var nthOverlay tui.Attr
+		if selected {
+			nthOverlay = t.theme.NthSelectedAttr
+		}
+		finalLineNum = t.printHighlighted(result, base, match, false, true, !matched, line, maxLine, forceRedraw, preTask, postTask, nthOverlay)
 	}
 	for i := 0; i < t.gap && finalLineNum < maxLine; i++ {
 		finalLineNum++
@@ -3570,7 +3729,7 @@ func (t *Terminal) overflow(runes []rune, max int) bool {
 	return t.displayWidthWithLimit(runes, 0, max) > max
 }
 
-func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMatch tui.ColorPair, current bool, match bool, hidden bool, lineNum int, maxLineNum int, forceRedraw bool, preTask func(markerClass) int, postTask func(int, int, bool, bool, tui.ColorPair)) int {
+func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMatch tui.ColorPair, current bool, match bool, hidden bool, lineNum int, maxLineNum int, forceRedraw bool, preTask func(markerClass) int, postTask func(int, int, bool, bool, tui.ColorPair), nthOverlay tui.Attr) int {
 	var displayWidth int
 	item := result.item
 	matchOffsets := []Offset{}
@@ -3611,7 +3770,9 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 			// But if 'nth' is set to 'regular', it's a sign that you're applying
 			// a different style to the rest of the string. e.g. 'nth:regular,fg:dim'
 			// In this case, we still need to apply it to clear the style.
-			colBase = colBase.WithAttr(t.nthAttr)
+			fgAttr := tui.ColNormal.Attr()
+			nthAttrFinal := fgAttr.Merge(t.nthAttr).Merge(nthOverlay)
+			colBase = colBase.WithNewAttr(nthAttrFinal)
 		}
 		if !wholeCovered && t.nthAttr > 0 {
 			var tokens []Token
@@ -3630,7 +3791,7 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 			sort.Sort(ByOrder(nthOffsets))
 		}
 	}
-	allOffsets := result.colorOffsets(charOffsets, nthOffsets, t.theme, colBase, colMatch, t.nthAttr, hidden)
+	allOffsets := result.colorOffsets(charOffsets, nthOffsets, t.theme, colBase, colMatch, t.nthAttr, nthOverlay, hidden)
 
 	// Determine split offset for horizontal scrolling with freeze
 	splitOffset1 := -1
@@ -3820,6 +3981,7 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 			frozenRight = line[splitOffsetRight:]
 		}
 		displayWidthSum := 0
+		displayWidthLeft := 0
 		todo := [3]func(){}
 		for fidx, runes := range [][]rune{frozenLeft, frozenRight, middle} {
 			if len(runes) == 0 {
@@ -3845,7 +4007,11 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 				// For frozen parts, reserve space for the ellipsis in the middle part
 				adjustedMaxWidth -= ellipsisWidth
 			}
-			displayWidth = t.displayWidthWithLimit(runes, 0, adjustedMaxWidth)
+			var prefixWidth int
+			if fidx == 2 {
+				prefixWidth = displayWidthLeft
+			}
+			displayWidth = t.displayWidthWithLimit(runes, prefixWidth, adjustedMaxWidth)
 			if !t.wrap && displayWidth > adjustedMaxWidth {
 				maxe = util.Constrain(maxe+min(maxWidth/2-ellipsisWidth, t.hscrollOff), 0, len(runes))
 				transformOffsets := func(diff int32) {
@@ -3883,6 +4049,9 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 				displayWidth = t.displayWidthWithLimit(runes, 0, maxWidth)
 			}
 			displayWidthSum += displayWidth
+			if fidx == 0 {
+				displayWidthLeft = displayWidth
+			}
 
 			if maxWidth > 0 {
 				color := colBase
@@ -3890,7 +4059,7 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 					color = color.WithFg(t.theme.Nomatch)
 				}
 				todo[fidx] = func() {
-					t.printColoredString(t.window, runes, offs, color)
+					t.printColoredString(t.window, runes, offs, color, prefixWidth)
 				}
 			} else {
 				break
@@ -3917,10 +4086,13 @@ func (t *Terminal) printHighlighted(result Result, colBase tui.ColorPair, colMat
 	return finalLineNum
 }
 
-func (t *Terminal) printColoredString(window tui.Window, text []rune, offsets []colorOffset, colBase tui.ColorPair) {
+func (t *Terminal) printColoredString(window tui.Window, text []rune, offsets []colorOffset, colBase tui.ColorPair, initialPrefixWidth ...int) {
 	var index int32
 	var substr string
 	var prefixWidth int
+	if len(initialPrefixWidth) > 0 {
+		prefixWidth = initialPrefixWidth[0]
+	}
 	maxOffset := int32(len(text))
 	var url *url
 	for _, offset := range offsets {
@@ -4127,7 +4299,7 @@ func (t *Terminal) followOffset() int {
 	for i := len(body) - 1; i >= 0; i-- {
 		h := t.previewLineHeight(body[i], maxWidth)
 		if visualLines+h > height {
-			return headerLines + i + 1
+			return min(len(lines)-1, headerLines+i+1)
 		}
 		visualLines += h
 	}
@@ -4425,7 +4597,7 @@ Loop:
 				}
 			}
 
-			t.previewer.scrollable = t.previewer.scrollable || t.pwindow.Y() == height-1 && t.pwindow.X() == t.pwindow.Width()
+			t.previewer.scrollable = t.previewer.scrollable || t.pwindow.Y() == height-1 && t.pwindow.X() == t.pwindow.Width() || t.previewed.filled
 			if fillRet == tui.FillNextLine {
 				continue
 			} else if fillRet == tui.FillSuspend {
@@ -4448,7 +4620,7 @@ Loop:
 		}
 		lineNo++
 	}
-	t.previewer.scrollable = t.previewer.scrollable || index < len(lines)-1
+	t.previewer.scrollable = t.previewer.scrollable || t.previewed.filled || index < len(lines)-1
 	t.previewed.image = image
 	t.previewed.wireframe = wireframe
 }
@@ -4458,7 +4630,7 @@ func (t *Terminal) renderPreviewScrollbar(yoff int, barLength int, barStart int)
 	w := t.pborder.Width()
 	xw := [2]int{t.pwindow.Left(), t.pwindow.Width()}
 	redraw := false
-	if len(t.previewer.bar) != height || t.previewer.xw != xw {
+	if len(t.previewer.bar) != height || t.previewer.xw != xw || t.previewed.version != t.previewer.version {
 		redraw = true
 		t.previewer.bar = make([]bool, height)
 		t.previewer.xw = xw
@@ -5270,6 +5442,22 @@ func (t *Terminal) currentIndex() int32 {
 	return minItem.Index()
 }
 
+func (t *Terminal) trackKeyFor(item *Item, nth []Range) string {
+	tokens := Tokenize(item.AsString(t.ansi), t.delimiter)
+	return StripLastDelimiter(JoinTokens(Transform(tokens, nth)), t.delimiter)
+}
+
+func (t *Terminal) unblockTrack() {
+	if t.trackBlocked {
+		t.trackBlocked = false
+		t.trackKey = ""
+		t.trackKeyCache = nil
+		if !t.inputless {
+			t.tui.ShowCursor()
+		}
+	}
+}
+
 func (t *Terminal) addClickHeaderWord(env []string) []string {
 	/*
 	 * echo $'HL1\nHL2' | fzf --header-lines 3 --header $'H1\nH2' --header-lines-border --bind 'click-header:preview:env | grep FZF_CLICK'
@@ -5288,9 +5476,13 @@ func (t *Terminal) addClickHeaderWord(env []string) []string {
 		return env
 	}
 
-	// NOTE: t.header is padded with empty strings so that its size is equal to t.headerLines
 	nthBase := 0
-	headers := [2][]string{t.header, t.header0}
+	// Convert header items to strings for click handling
+	headerStrs := make([]string, len(t.header))
+	for i, item := range t.header {
+		headerStrs[i] = item.text.ToString()
+	}
+	headers := [2][]string{headerStrs, t.header0}
 	if t.layout == layoutReverse {
 		headers[0], headers[1] = headers[1], headers[0]
 	}
@@ -5892,6 +6084,8 @@ func (t *Terminal) Loop() error {
 	events := []util.EventType{}
 	changed := false
 	var newNth *[]Range
+	var newWithNth *withNthSpec
+	var newHeaderLines *int
 	req := func(evts ...util.EventType) {
 		for _, event := range evts {
 			events = append(events, event)
@@ -5908,6 +6102,8 @@ func (t *Terminal) Loop() error {
 		events = []util.EventType{}
 		changed = false
 		newNth = nil
+		newWithNth = nil
+		newHeaderLines = nil
 		beof := false
 		queryChanged := false
 		denylist := []int32{}
@@ -6083,6 +6279,14 @@ func (t *Terminal) Loop() error {
 					callback(a.a)
 				}
 			}
+			// When track-blocked, only allow abort/cancel and track-disabling actions
+			if t.trackBlocked && a.t != actToggleTrack && a.t != actToggleTrackCurrent && a.t != actUntrackCurrent {
+				if a.t == actAbort || a.t == actCancel {
+					t.unblockTrack()
+					req(reqPrompt, reqInfo)
+				}
+				return true
+			}
 		Action:
 			switch a.t {
 			case actIgnore, actStart, actClick:
@@ -6247,6 +6451,23 @@ func (t *Terminal) Loop() error {
 				}
 			case actPrintQuery:
 				req(reqPrintQuery)
+			case actChangeHeaderLines, actTransformHeaderLines, actBgTransformHeaderLines:
+				capture(true, func(expr string) {
+					if n, err := strconv.Atoi(expr); err == nil && n >= 0 && n != t.headerLines {
+						t.headerLines = n
+						newHeaderLines = &n
+						changed = true
+						// Deselect items that are now part of the header
+						for idx := range t.selected {
+							if idx < int32(n) {
+								delete(t.selected, idx)
+							}
+						}
+						// Tell UpdateList to reposition cursor to the current item
+						t.targetIndex = t.currentIndex()
+						req(reqList, reqPrompt, reqInfo, reqHeader)
+					}
+				})
 			case actChangeMulti:
 				multi := t.multi
 				if a.a == "" {
@@ -6281,6 +6502,33 @@ func (t *Terminal) Loop() error {
 						t.forceRerenderList()
 					}
 				})
+			case actChangeWithNth, actTransformWithNth, actBgTransformWithNth:
+				if !t.withNthEnabled {
+					break Action
+				}
+				capture(true, func(expr string) {
+					tokens := strings.Split(expr, "|")
+					withNthExpr := tokens[0]
+					if len(tokens) > 1 {
+						a.a = strings.Join(append(tokens[1:], tokens[0]), "|")
+					}
+					// Empty value restores the default --with-nth
+					if len(withNthExpr) == 0 {
+						withNthExpr = t.withNthDefault
+					}
+					if withNthExpr != t.withNthExpr {
+						if factory, err := nthTransformer(withNthExpr); err == nil {
+							newWithNth = &withNthSpec{fn: factory(t.delimiter)}
+						} else {
+							return
+						}
+						t.withNthExpr = withNthExpr
+						t.filterSelection = true
+						changed = true
+						t.clearNumLinesCache()
+						t.forceRerenderList()
+					}
+				})
 			case actChangeQuery:
 				t.input = []rune(a.a)
 				t.cx = len(t.input)
@@ -6810,14 +7058,16 @@ func (t *Terminal) Loop() error {
 				case trackDisabled:
 					t.track = trackEnabled
 				}
-				req(reqInfo)
+				t.unblockTrack()
+				req(reqPrompt, reqInfo)
 			case actToggleTrackCurrent:
 				if t.track.Current() {
 					t.track = trackDisabled
 				} else if t.track.Disabled() {
 					t.track = trackCurrent(t.currentIndex())
 				}
-				req(reqInfo)
+				t.unblockTrack()
+				req(reqPrompt, reqInfo)
 			case actShowHeader:
 				t.headerVisible = true
 				req(reqList, reqInfo, reqPrompt, reqHeader)
@@ -6880,7 +7130,8 @@ func (t *Terminal) Loop() error {
 				if t.track.Current() {
 					t.track = trackDisabled
 				}
-				req(reqInfo)
+				t.unblockTrack()
+				req(reqPrompt, reqInfo)
 			case actSearch:
 				override := []rune(a.a)
 				t.inputOverride = &override
@@ -6933,10 +7184,12 @@ func (t *Terminal) Loop() error {
 				}
 				if !me.Down {
 					barDragging = false
+					pmx, pmy = -1, -1
+				}
+				if !me.Down || !t.hasPreviewWindow() {
 					pbarDragging = false
 					pborderDragging = -1
 					previewDraggingPos = -1
-					pmx, pmy = -1, -1
 				}
 
 				// Scrolling
@@ -6964,7 +7217,7 @@ func (t *Terminal) Loop() error {
 				}
 
 				// Preview dragging
-				if me.Down && (previewDraggingPos >= 0 || click && t.hasPreviewWindow() && t.pwindow.Enclose(my, mx)) {
+				if t.hasPreviewWindow() && me.Down && (previewDraggingPos >= 0 || click && t.pwindow.Enclose(my, mx)) {
 					if previewDraggingPos > 0 {
 						scrollPreviewBy(previewDraggingPos - my)
 					}
@@ -6974,7 +7227,7 @@ func (t *Terminal) Loop() error {
 
 				// Preview scrollbar dragging
 				headerLines := t.activePreviewOpts.headerLines
-				pbarDragging = me.Down && (pbarDragging || click && t.hasPreviewWindow() && my >= t.pwindow.Top()+headerLines && my < t.pwindow.Top()+t.pwindow.Height() && mx == t.pwindow.Left()+t.pwindow.Width())
+				pbarDragging = t.hasPreviewWindow() && me.Down && (pbarDragging || click && my >= t.pwindow.Top()+headerLines && my < t.pwindow.Top()+t.pwindow.Height() && mx == t.pwindow.Left()+t.pwindow.Width())
 				if pbarDragging {
 					effectiveHeight := t.pwindow.Height() - headerLines
 					numLines := len(t.previewer.lines) - headerLines
@@ -6991,7 +7244,7 @@ func (t *Terminal) Loop() error {
 				}
 
 				// Preview border dragging (resizing)
-				if pborderDragging < 0 && click && t.hasPreviewWindow() {
+				if t.hasPreviewWindow() && pborderDragging < 0 && click {
 					switch t.activePreviewOpts.position {
 					case posUp:
 						if t.pborder.Enclose(my, mx) && my == t.pborder.Top()+t.pborder.Height()-1 {
@@ -7020,7 +7273,7 @@ func (t *Terminal) Loop() error {
 					}
 				}
 
-				if pborderDragging >= 0 && t.hasPreviewWindow() {
+				if t.hasPreviewWindow() && pborderDragging >= 0 {
 					var newSize int
 					var prevSize int
 					switch t.activePreviewOpts.position {
@@ -7231,6 +7484,22 @@ func (t *Terminal) Loop() error {
 					newCommand = &commandSpec{command, tempFiles}
 					reloadSync = a.t == actReloadSync
 					t.reading = true
+
+					if len(t.idNth) > 0 {
+						t.trackSync = reloadSync
+					}
+					// Capture tracking key before reload
+					if !t.track.Disabled() && len(t.idNth) > 0 {
+						if item := t.currentItem(); item != nil {
+							t.trackKey = t.trackKeyFor(item, t.idNth)
+							t.trackKeyCache = make(map[int32]bool)
+							t.trackBlocked = true
+							if !t.inputless {
+								t.tui.HideCursor()
+							}
+							req(reqPrompt, reqInfo)
+						}
+					}
 				}
 			case actUnbind:
 				if keys, _, err := parseKeyChords(a.a, "PANIC"); err == nil {
@@ -7428,12 +7697,17 @@ func (t *Terminal) Loop() error {
 		reload := changed || newCommand != nil
 		var reloadRequest *searchRequest
 		if reload {
-			reloadRequest = &searchRequest{sort: t.sort, sync: reloadSync, nth: newNth, command: newCommand, environ: t.environ(), changed: changed, denylist: denylist, revision: t.resultMerger.Revision()}
+			reloadRequest = &searchRequest{sort: t.sort, sync: reloadSync, nth: newNth, withNth: newWithNth, headerLines: newHeaderLines, command: newCommand, environ: t.environ(), changed: changed, denylist: denylist, revision: t.resultMerger.Revision()}
 		}
 
 		// Dispatch queued background requests
 		t.dispatchAsync()
 
+		if t.pendingReqList {
+			t.pendingReqList = false
+			req(reqList)
+		}
+
 		t.mutex.Unlock() // Must be unlocked before touching reqBox
 
 		if reload {
@@ -7598,10 +7872,18 @@ func (t *Terminal) dumpItem(i *Item) StatusItem {
 	if i == nil {
 		return StatusItem{}
 	}
-	return StatusItem{
+	item := StatusItem{
 		Index: int(i.Index()),
 		Text:  i.AsString(t.ansi),
 	}
+	if t.resultMerger.pattern != nil {
+		_, _, pos := t.resultMerger.pattern.MatchItem(i, true, t.slab)
+		if pos != nil {
+			sort.Ints(*pos)
+			item.Positions = *pos
+		}
+	}
+	return item
 }
 
 func (t *Terminal) tryLock(timeout time.Duration) bool {

src/tmux.go

@@ -1,39 +1,11 @@
 package fzf
 
 import (
-	"os"
 	"os/exec"
-
-	"github.com/junegunn/fzf/src/tui"
 )
 
 func runTmux(args []string, opts *Options) (int, error) {
-	// Prepare arguments
-	fzf, rest := args[0], args[1:]
-	args = []string{"--bind=ctrl-z:ignore"}
-	if !opts.Tmux.border && (opts.BorderShape == tui.BorderUndefined || opts.BorderShape == tui.BorderLine) {
-		// We append --border option at the end, because `--style=full:STYLE`
-		// may have changed the default border style.
-		if tui.DefaultBorderShape == tui.BorderRounded {
-			rest = append(rest, "--border=rounded")
-		} else {
-			rest = append(rest, "--border=sharp")
-		}
-	}
-	if opts.Tmux.border && opts.Margin == defaultMargin() {
-		args = append(args, "--margin=0,1")
-	}
-	argStr := escapeSingleQuote(fzf)
-	for _, arg := range append(args, rest...) {
-		argStr += " " + escapeSingleQuote(arg)
-	}
-	argStr += ` --no-tmux --no-height`
-
-	// Get current directory
-	dir, err := os.Getwd()
-	if err != nil {
-		dir = "."
-	}
+	argStr, dir := popupArgStr(args, opts)
 
 	// Set tmux options for popup placement
 	// C        Both    The centre of the terminal

src/tokenizer.go

@@ -161,7 +161,7 @@ func awkTokenizer(input string) ([]string, int) {
 	end := 0
 	for idx := 0; idx < len(input); idx++ {
 		r := input[idx]
-		white := r == 9 || r == 32
+		white := r == 9 || r == 32 || r == 10
 		switch state {
 		case awkNil:
 			if white {
@@ -218,11 +218,12 @@ func Tokenize(text string, delimiter Delimiter) []Token {
 	return withPrefixLengths(tokens, 0)
 }
 
-// StripLastDelimiter removes the trailing delimiter and whitespaces
+// StripLastDelimiter removes the trailing delimiter
 func StripLastDelimiter(str string, delimiter Delimiter) string {
 	if delimiter.str != nil {
-		str = strings.TrimSuffix(str, *delimiter.str)
-	} else if delimiter.regex != nil {
+		return strings.TrimSuffix(str, *delimiter.str)
+	}
+	if delimiter.regex != nil {
 		locs := delimiter.regex.FindAllStringIndex(str, -1)
 		if len(locs) > 0 {
 			lastLoc := locs[len(locs)-1]
@@ -230,6 +231,7 @@ func StripLastDelimiter(str string, delimiter Delimiter) string {
 				str = str[:lastLoc[0]]
 			}
 		}
+		return str
 	}
 	return strings.TrimRightFunc(str, unicode.IsSpace)
 }

src/tokenizer_test.go

@@ -56,9 +56,9 @@ func TestParseRange(t *testing.T) {
 
 func TestTokenize(t *testing.T) {
 	// AWK-style
-	input := "  abc:  def:  ghi  "
+	input := "  abc: \n\t def:  ghi  "
 	tokens := Tokenize(input, Delimiter{})
-	if tokens[0].text.ToString() != "abc:  " || tokens[0].prefixLength != 2 {
+	if tokens[0].text.ToString() != "abc: \n\t " || tokens[0].prefixLength != 2 {
 		t.Errorf("%s", tokens)
 	}
 
@@ -71,9 +71,9 @@ func TestTokenize(t *testing.T) {
 	// With delimiter regex
 	tokens = Tokenize(input, delimiterRegexp("\\s+"))
 	if tokens[0].text.ToString() != "  " || tokens[0].prefixLength != 0 ||
-		tokens[1].text.ToString() != "abc:  " || tokens[1].prefixLength != 2 ||
-		tokens[2].text.ToString() != "def:  " || tokens[2].prefixLength != 8 ||
-		tokens[3].text.ToString() != "ghi  " || tokens[3].prefixLength != 14 {
+		tokens[1].text.ToString() != "abc: \n\t " || tokens[1].prefixLength != 2 ||
+		tokens[2].text.ToString() != "def:  " || tokens[2].prefixLength != 10 ||
+		tokens[3].text.ToString() != "ghi  " || tokens[3].prefixLength != 16 {
 		t.Errorf("%s", tokens)
 	}
 }

src/tui/tui.go

@@ -447,6 +447,12 @@ func (p ColorPair) WithAttr(attr Attr) ColorPair {
 	return dup
 }
 
+func (p ColorPair) WithNewAttr(attr Attr) ColorPair {
+	dup := p
+	dup.attr = attr
+	return dup
+}
+
 func (p ColorPair) WithFg(fg ColorAttr) ColorPair {
 	dup := p
 	fgPair := ColorPair{fg.Color, colUndefined, colUndefined, fg.Attr}
@@ -520,6 +526,8 @@ type ColorTheme struct {
 	ListLabel        ColorAttr
 	ListBorder       ColorAttr
 	GapLine          ColorAttr
+	NthCurrentAttr   Attr // raw current-fg attr (before fg merge) for nth overlay
+	NthSelectedAttr  Attr // raw selected-fg attr (before ListFg inherit) for nth overlay
 }
 
 type Event struct {
@@ -1199,13 +1207,19 @@ func InitTheme(theme *ColorTheme, baseTheme *ColorTheme, boldify bool, forceBlac
 		match.Attr = Underline
 	}
 	theme.Match = o(baseTheme.Match, match)
-	// Inherit from 'fg', so that we don't have to write 'current-fg:dim'
+	// These colors are not defined in the base themes.
+	// Resolve ListFg/ListBg early so Current and Selected can inherit from them.
+	theme.ListFg = o(theme.Fg, theme.ListFg)
+	theme.ListBg = o(theme.Bg, theme.ListBg)
+	// Inherit from 'list-fg', so that we don't have to write 'current-fg:dim'
 	// e.g. fzf --delimiter / --nth -1 --color fg:dim,nth:regular
 	current := theme.Current
 	if !baseTheme.Colored && current.IsUndefined() {
 		current.Attr |= Reverse
 	}
-	theme.Current = theme.Fg.Merge(o(baseTheme.Current, current))
+	resolvedCurrent := o(baseTheme.Current, current)
+	theme.NthCurrentAttr = resolvedCurrent.Attr
+	theme.Current = theme.ListFg.Merge(resolvedCurrent)
 	currentMatch := theme.CurrentMatch
 	if !baseTheme.Colored && currentMatch.IsUndefined() {
 		currentMatch.Attr |= Reverse | Underline
@@ -1230,10 +1244,8 @@ func InitTheme(theme *ColorTheme, baseTheme *ColorTheme, boldify bool, forceBlac
 	scrollbarDefined := theme.Scrollbar != undefined
 	previewBorderDefined := theme.PreviewBorder != undefined
 
-	// These colors are not defined in the base themes
-	theme.ListFg = o(theme.Fg, theme.ListFg)
-	theme.ListBg = o(theme.Bg, theme.ListBg)
-	theme.SelectedFg = o(theme.ListFg, theme.SelectedFg)
+	theme.NthSelectedAttr = theme.SelectedFg.Attr
+	theme.SelectedFg = theme.ListFg.Merge(theme.SelectedFg)
 	theme.SelectedBg = o(theme.ListBg, theme.SelectedBg)
 	theme.SelectedMatch = o(theme.Match, theme.SelectedMatch)
 

src/util/util_unix.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 	"syscall"
 
+	"github.com/junegunn/go-shellwords"
 	"golang.org/x/sys/unix"
 )
 
@@ -20,8 +21,8 @@ type Executor struct {
 
 func NewExecutor(withShell string) *Executor {
 	shell := os.Getenv("SHELL")
-	args := strings.Fields(withShell)
-	if len(args) > 0 {
+	args, err := shellwords.Parse(withShell)
+	if err == nil && len(args) > 0 {
 		shell = args[0]
 		args = args[1:]
 	} else {

src/zellij.go

@@ -0,0 +1,41 @@
+package fzf
+
+import (
+	"os/exec"
+)
+
+func runZellij(args []string, opts *Options) (int, error) {
+	argStr, dir := popupArgStr(args, opts)
+
+	zellijArgs := []string{
+		"run", "--floating", "--close-on-exit", "--block-until-exit",
+		"--cwd", dir,
+	}
+	if !opts.Tmux.border {
+		zellijArgs = append(zellijArgs, "--borderless", "true")
+	}
+	switch opts.Tmux.position {
+	case posUp:
+		zellijArgs = append(zellijArgs, "-y", "0")
+	case posDown:
+		zellijArgs = append(zellijArgs, "-y", "9999")
+	case posLeft:
+		zellijArgs = append(zellijArgs, "-x", "0")
+	case posRight:
+		zellijArgs = append(zellijArgs, "-x", "9999")
+	case posCenter:
+		// Zellij centers floating panes by default
+	}
+	zellijArgs = append(zellijArgs, "--width", opts.Tmux.width.String())
+	zellijArgs = append(zellijArgs, "--height", opts.Tmux.height.String())
+	zellijArgs = append(zellijArgs, "--")
+
+	return runProxy(argStr, func(temp string, needBash bool) (*exec.Cmd, error) {
+		sh, err := sh(needBash)
+		if err != nil {
+			return nil, err
+		}
+		zellijArgs = append(zellijArgs, sh, temp)
+		return exec.Command("zellij", zellijArgs...), nil
+	}, opts, true)
+}

test/test_core.rb

@@ -404,11 +404,11 @@ class TestCore < TestInteractive
       tmux.send_keys "seq 1 111 | #{fzf("-m +s --tac #{opt} -q11")}", :Enter
       tmux.until { |lines| assert_equal '> 111', lines[-3] }
       tmux.send_keys :Tab
-      tmux.until { |lines| assert_equal '  4/111 -S (1)', lines[-2] }
+      tmux.until { |lines| assert_equal '  4/111 (1) -S', lines[-2] }
       tmux.send_keys 'C-R'
       tmux.until { |lines| assert_equal '> 11', lines[-3] }
       tmux.send_keys :Tab
-      tmux.until { |lines| assert_equal '  4/111 +S (2)', lines[-2] }
+      tmux.until { |lines| assert_equal '  4/111 (2) +S', lines[-2] }
       tmux.send_keys :Enter
       assert_equal %w[111 11], fzf_output_lines
     end
@@ -1190,6 +1190,16 @@ class TestCore < TestInteractive
     tmux.until { |lines| assert lines.any_include?('9999␊10000') }
   end
 
+  def test_freeze_left_tabstop
+    writelines(%W[1\t2\t3])
+    # With --freeze-left 1 and --tabstop=2:
+    # Frozen left: "1" (width 1)
+    # Middle starts with "\t" at prefix width 1, tabstop 2 → 1 space
+    # Then "2" at column 2, next "\t" at column 3 → 1 space, then "3"
+    tmux.send_keys %(cat #{tempname} | #{FZF} --tabstop=2 --freeze-left 1), :Enter
+    tmux.until { |lines| assert_equal '> 1 2 3', lines[-3] }
+  end
+
   def test_freeze_left_keep_right
     tmux.send_keys %(seq 10000 | #{FZF} --read0 --delimiter "\n" --freeze-left 3 --keep-right --ellipsis XX --no-multi-line --bind space:toggle-multi-line), :Enter
     tmux.until { |lines| assert_match(/^> 1␊2␊3XX.*10000␊$/, lines[-3]) }
@@ -1649,6 +1659,236 @@ class TestCore < TestInteractive
     end
   end
 
+  def test_track_nth_reload_whole_line
+    # --track --id-nth .. should track by entire line across reloads
+    tmux.send_keys "seq 1000 | #{FZF} --track --id-nth .. --bind 'ctrl-r:reload:seq 1000 | sort -R'", :Enter
+    tmux.until { |lines| assert_equal 1000, lines.match_count }
+
+    # Move to item 555
+    tmux.send_keys '555'
+    tmux.until do |lines|
+      assert_equal 1, lines.match_count
+      assert_includes lines, '> 555'
+    end
+    tmux.send_keys :BSpace, :BSpace, :BSpace
+
+    # Reload with shuffled order — cursor should track "555"
+    tmux.send_keys 'C-r'
+    tmux.until do |lines|
+      assert_equal 1000, lines.match_count
+      assert_includes lines, '> 555'
+      assert_includes lines[-2], '+T'
+      refute_includes lines[-2], '+T*'
+    end
+  end
+
+  def test_track_nth_reload_field
+    # --track --id-nth 1 should track by first field across reloads
+    tmux.send_keys "printf '1 apple\\n2 banana\\n3 cherry\\n' | #{FZF} --track --id-nth 1 --bind 'ctrl-r:reload:printf \"1 apricot\\n2 blueberry\\n3 cranberry\\n\"'", :Enter
+    tmux.until do |lines|
+      assert_equal 3, lines.match_count
+      assert_includes lines, '> 1 apple'
+    end
+
+    # Move up to "2 banana"
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_includes lines, '> 2 banana' }
+
+    # Reload — the second field changes, but first field "2" stays
+    tmux.send_keys 'C-r'
+    tmux.until do |lines|
+      assert_equal 3, lines.match_count
+      assert_includes lines, '> 2 blueberry'
+    end
+  end
+
+  def test_track_nth_reload_no_match
+    # When tracked item is not found after reload, cursor stays at current position
+    tmux.send_keys "printf 'alpha\\nbeta\\ngamma\\n' | #{FZF} --track --id-nth .. --bind 'ctrl-r:reload:printf \"delta\\nepsilon\\nzeta\\n\"'", :Enter
+    tmux.until { |lines| assert_equal 3, lines.match_count }
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_includes lines, '> beta' }
+
+    # Reload with completely different items — no match for "beta"
+    # Cursor stays at the same position (second item)
+    tmux.send_keys 'C-r'
+    tmux.until do |lines|
+      assert_equal 3, lines.match_count
+      assert_includes lines, '> epsilon'
+      refute_includes lines[-2], '+T*'
+    end
+  end
+
+  def test_track_nth_blocked_indicator
+    # +T* should appear during reload and disappear when match is found
+    tmux.send_keys "seq 100 | #{FZF} --track --id-nth .. --bind 'ctrl-r:reload:sleep 1; seq 100 | sort -R'", :Enter
+    tmux.until do |lines|
+      assert_equal 100, lines.match_count
+      assert_includes lines[-2], '+T'
+    end
+
+    # Trigger slow reload — should show +T* while blocked
+    tmux.send_keys 'C-r'
+    tmux.until { |lines| assert_includes lines[-2], '+T*' }
+
+    # After reload completes, +T* should clear back to +T
+    tmux.until do |lines|
+      assert_equal 100, lines.match_count
+      assert_includes lines[-2], '+T'
+      refute_includes lines[-2], '+T*'
+    end
+  end
+
+  def test_track_nth_abort_unblocks
+    # Escape during track-blocked state should unblock, not quit
+    tmux.send_keys "seq 100 | #{FZF} --track --id-nth .. --bind 'ctrl-r:reload:sleep 3; seq 100'", :Enter
+    tmux.until do |lines|
+      assert_equal 100, lines.match_count
+      assert_includes lines[-2], '+T'
+    end
+
+    # Trigger slow reload
+    tmux.send_keys 'C-r'
+    tmux.until { |lines| assert_includes lines[-2], '+T*' }
+
+    # Escape should unblock, not quit fzf
+    tmux.send_keys :Escape
+    tmux.until do |lines|
+      assert_includes lines[-2], '+T'
+      refute_includes lines[-2], '+T*'
+    end
+  end
+
+  def test_track_nth_reload_async_unblocks_early
+    # With async reload, +T* should clear as soon as the match streams in,
+    # even while loading is still in progress.
+    # sleep 1 first so +T* is observable, then the match arrives, then more items after a delay.
+    tmux.send_keys "seq 5 | #{FZF} --track --id-nth .. --bind 'ctrl-r:reload:sleep 1; echo 1; sleep 2; seq 2 10'", :Enter
+    tmux.until do |lines|
+      assert_equal 5, lines.match_count
+      assert_includes lines, '> 1'
+    end
+
+    # Trigger reload — blocked during initial sleep
+    tmux.send_keys 'C-r'
+    tmux.until { |lines| assert_includes lines[-2], '+T*' }
+    # Match "1" arrives, unblocks before the remaining items load
+    tmux.until do |lines|
+      assert_equal 1, lines.match_count
+      assert_includes lines, '> 1'
+      assert_includes lines[-2], '+T'
+      refute_includes lines[-2], '+T*'
+    end
+  end
+
+  def test_track_nth_reload_sync_blocks_until_complete
+    # With reload-sync, +T* should stay until the entire stream is complete,
+    # even though the match arrives early in the stream.
+    tmux.send_keys "seq 5 | #{FZF} --track --id-nth .. --bind 'ctrl-r:reload-sync:sleep 1; echo 1; sleep 2; seq 2 10'", :Enter
+    tmux.until do |lines|
+      assert_equal 5, lines.match_count
+      assert_includes lines, '> 1'
+    end
+
+    # Trigger reload-sync — every observable state must be either:
+    # 1. +T* (still blocked), or
+    # 2. final state (count=10, +T without *)
+    # Any other combination (e.g. unblocked while count < 10) is a bug.
+    tmux.send_keys 'C-r'
+    tmux.until do |lines|
+      info = lines[-2]
+      blocked = info&.include?('+T*')
+      unless blocked
+        raise "Unblocked before stream complete (count: #{lines.match_count})" if lines.match_count != 10
+
+        assert_includes info, '+T'
+        assert_includes lines, '> 1'
+      end
+      !blocked
+    end
+  end
+
+  def test_track_nth_toggle_track_unblocks
+    # toggle-track during track-blocked state should unblock and disable tracking
+    tmux.send_keys "seq 100 | #{FZF} --track --id-nth .. --bind 'ctrl-r:reload:sleep 5; seq 100' --bind 'ctrl-t:toggle-track'", :Enter
+    tmux.until do |lines|
+      assert_equal 100, lines.match_count
+      assert_includes lines[-2], '+T'
+    end
+
+    # Trigger slow reload
+    tmux.send_keys 'C-r'
+    tmux.until { |lines| assert_includes lines[-2], '+T*' }
+
+    # toggle-track should unblock and disable tracking before reload completes
+    tmux.send_keys 'C-t'
+    tmux.until(timeout: 3) do |lines|
+      refute_includes lines[-2], '+T'
+    end
+  end
+
+  def test_track_nth_reload_async_no_match
+    # With async reload, when tracked item is not found, cursor stays at
+    # current position after stream completes
+    tmux.send_keys "printf 'alpha\\nbeta\\ngamma\\n' | #{FZF} --track --id-nth .. --bind 'ctrl-r:reload:sleep 1; printf \"delta\\nepsilon\\nzeta\\n\"'", :Enter
+    tmux.until { |lines| assert_equal 3, lines.match_count }
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_includes lines, '> beta' }
+
+    # Reload with completely different items — no match for "beta"
+    tmux.send_keys 'C-r'
+    tmux.until { |lines| assert_includes lines[-2], '+T*' }
+    # After stream completes, unblocks with cursor at same position (second item)
+    tmux.until do |lines|
+      assert_equal 3, lines.match_count
+      assert_includes lines, '> epsilon'
+      refute_includes lines[-2], '+T*'
+    end
+  end
+
+  def test_track_action_with_id_nth
+    # track-current with --id-nth should track by specified field
+    tmux.send_keys "printf '1 apple\\n2 banana\\n3 cherry\\n' | #{FZF} --id-nth 1 --bind 'ctrl-t:track-current,ctrl-r:reload:printf \"1 apricot\\n2 blueberry\\n3 cranberry\\n\"'", :Enter
+    tmux.until { |lines| assert_equal 3, lines.match_count }
+
+    # Move to "2 banana" and activate tracking
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_includes lines, '> 2 banana' }
+    tmux.send_keys 'C-t'
+    tmux.until { |lines| assert_includes lines[-2], '+t' }
+
+    # Reload — should track by field "2"
+    tmux.send_keys 'C-r'
+    tmux.until do |lines|
+      assert_equal 3, lines.match_count
+      assert_includes lines, '> 2 blueberry'
+    end
+  end
+
+  def test_id_nth_preserve_multi_selection
+    # --id-nth with --multi should preserve selections across reload-sync
+    File.write(tempname, "1 apricot\n2 blueberry\n3 cranberry\n")
+    tmux.send_keys "printf '1 apple\\n2 banana\\n3 cherry\\n' | #{fzf("--multi --id-nth 1 --bind 'ctrl-r:reload-sync:cat #{tempname}'")}", :Enter
+    tmux.until { |lines| assert_equal 3, lines.match_count }
+
+    # Select first item (1 apple) and third item (3 cherry)
+    tmux.send_keys :Tab
+    tmux.send_keys :Up, :Up, :Tab
+    tmux.until { |lines| assert_includes lines[-2], '(2)' }
+
+    # Reload — selections should be preserved by id-nth key
+    tmux.send_keys 'C-r'
+    tmux.until do |lines|
+      assert_equal 3, lines.match_count
+      assert_includes lines[-2], '(2)'
+      assert(lines.any? { |l| l.include?('apricot') })
+    end
+
+    # Accept and verify the correct items were preserved
+    tmux.send_keys :Enter
+    assert_equal ['1 apricot', '3 cranberry'], fzf_output_lines
+  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'
@@ -1745,6 +1985,191 @@ class TestCore < TestInteractive
     end
   end
 
+  def test_change_with_nth
+    input = [
+      'foo bar baz',
+      'aaa bbb ccc',
+      'xxx yyy zzz'
+    ]
+    writelines(input)
+    # Start with field 1 only, cycle through fields, verify $FZF_WITH_NTH via prompt
+    tmux.send_keys %(#{FZF} --with-nth 1 --bind 'space:change-with-nth(2|3|1),result:transform-prompt:echo "[$FZF_WITH_NTH]> "' < #{tempname}), :Enter
+    tmux.until do |lines|
+      assert_equal 3, lines.item_count
+      assert lines.any_include?('[1]>')
+      assert lines.any_include?('foo')
+      refute lines.any_include?('bar')
+    end
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert lines.any_include?('[2]>')
+      assert lines.any_include?('bar')
+      refute lines.any_include?('foo')
+    end
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert lines.any_include?('[3]>')
+      assert lines.any_include?('baz')
+      refute lines.any_include?('bar')
+    end
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert lines.any_include?('[1]>')
+      assert lines.any_include?('foo')
+      refute lines.any_include?('bar')
+    end
+  end
+
+  def test_change_with_nth_default
+    # Empty value restores the default --with-nth
+    tmux.send_keys %(echo -e 'a b c\nd e f' | #{FZF} --with-nth 1 --bind 'space:change-with-nth(2|)'), :Enter
+    tmux.until do |lines|
+      assert_equal 2, lines.item_count
+      assert lines.any_include?('a')
+      refute lines.any_include?('b')
+    end
+    # Switch to field 2
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert lines.any_include?('b')
+      refute lines.any_include?('a')
+    end
+    # Empty restores default (field 1)
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert lines.any_include?('a')
+      refute lines.any_include?('b')
+    end
+  end
+
+  def test_transform_with_nth_search
+    input = [
+      'alpha bravo charlie',
+      'delta echo foxtrot',
+      'golf hotel india'
+    ]
+    writelines(input)
+    tmux.send_keys %(#{FZF} --with-nth 1 --bind 'space:transform-with-nth(echo 2)' -q '^bravo$' < #{tempname}), :Enter
+    tmux.until do |lines|
+      assert_equal 0, lines.match_count
+    end
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert_equal 1, lines.match_count
+    end
+  end
+
+  def test_bg_transform_with_nth_output
+    tmux.send_keys %(echo -e 'a b c\nd e f' | #{FZF} --with-nth 2 --bind 'space:bg-transform-with-nth(echo 3)'), :Enter
+    tmux.until do |lines|
+      assert_equal 2, lines.item_count
+      assert lines.any_include?('b')
+    end
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert lines.any_include?('c')
+      refute lines.any_include?('b')
+    end
+    tmux.send_keys :Enter
+    tmux.until { |lines| assert lines.any_include?('a b c') || lines.any_include?('d e f') }
+  end
+
+  def test_change_with_nth_search
+    input = [
+      'alpha bravo charlie',
+      'delta echo foxtrot',
+      'golf hotel india'
+    ]
+    writelines(input)
+    tmux.send_keys %(#{FZF} --with-nth 1 --bind 'space:change-with-nth(2)' -q '^bravo$' < #{tempname}), :Enter
+    tmux.until do |lines|
+      assert_equal 0, lines.match_count
+    end
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert_equal 1, lines.match_count
+    end
+  end
+
+  def test_change_with_nth_output
+    tmux.send_keys %(echo -e 'a b c\nd e f' | #{FZF} --with-nth 2 --bind 'space:change-with-nth(3)'), :Enter
+    tmux.until do |lines|
+      assert_equal 2, lines.item_count
+      assert lines.any_include?('b')
+    end
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert lines.any_include?('c')
+      refute lines.any_include?('b')
+    end
+    tmux.send_keys :Enter
+    tmux.until { |lines| assert lines.any_include?('a b c') || lines.any_include?('d e f') }
+  end
+
+  def test_change_with_nth_selection
+    # Items: field1 has unique values, field2 has 'match' or 'miss'
+    input = [
+      'one match x',
+      'two miss y',
+      'three match z'
+    ]
+    writelines(input)
+    # Start showing field 2 (match/miss), query 'match', select all matches, then switch to field 3
+    tmux.send_keys %(#{FZF} --with-nth 2 --multi --bind 'ctrl-a:select-all,space:change-with-nth(3)' -q match < #{tempname}), :Enter
+    tmux.until do |lines|
+      assert_equal 2, lines.match_count
+    end
+    # Select all matching items
+    tmux.send_keys 'C-a'
+    tmux.until do |lines|
+      assert lines.any_include?('(2)')
+    end
+    # Now change with-nth to field 3; 'x' and 'z' don't contain 'match'
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert_equal 0, lines.match_count
+      # Selections of non-matching items should be cleared
+      assert lines.any_include?('(0)')
+    end
+  end
+
+  def test_change_with_nth_multiline
+    # Each item has 3 lines: "N-a\nN-b\nN-c"
+    # --with-nth 1 shows 1 line per item, --with-nth 1..3 shows 3 lines per item
+    tmux.send_keys %(seq 20 | xargs -I{} printf '{}-a\\n{}-b\\n{}-c\\0' | #{FZF} --read0 --delimiter "\n" --with-nth 1 --bind 'space:change-with-nth(1..3|1)' --no-sort), :Enter
+    tmux.until do |lines|
+      assert_equal 20, lines.item_count
+      assert lines.any_include?('1-a')
+      refute lines.any_include?('1-b')
+    end
+    # Expand to 3 lines per item
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert lines.any_include?('1-a')
+      assert lines.any_include?('1-b')
+      assert lines.any_include?('1-c')
+    end
+    # Scroll down a few items
+    5.times { tmux.send_keys :Down }
+    tmux.until do |lines|
+      assert lines.any_include?('6-a')
+      assert lines.any_include?('6-b')
+      assert lines.any_include?('6-c')
+    end
+    # Collapse back to 1 line per item
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert lines.any_include?('6-a')
+      refute lines.any_include?('6-b')
+    end
+    # Scroll down more after collapse
+    5.times { tmux.send_keys :Down }
+    tmux.until do |lines|
+      assert lines.any_include?('11-a')
+      refute lines.any_include?('11-b')
+    end
+  end
+
   def test_env_vars
     def env_vars
       return {} unless File.exist?(tempname)
@@ -1755,7 +2180,7 @@ class TestCore < TestInteractive
       end
     end
 
-    tmux.send_keys %(seq 100 | #{FZF} --multi --reverse --preview-window 0 --preview 'env | grep ^FZF_ | sort > #{tempname}' --no-input --bind enter:show-input+refresh-preview,space:disable-search+refresh-preview), :Enter
+    tmux.send_keys %({ echo foo; seq 100; } | #{FZF} --header-lines 1 --multi --reverse --preview-window 0 --preview 'env | grep ^FZF_ | sort > #{tempname}' --no-input --bind enter:show-input+refresh-preview,space:disable-search+refresh-preview), :Enter
     expected = {
       FZF_DIRECTION: 'down',
       FZF_TOTAL_COUNT: '100',
@@ -1900,13 +2325,13 @@ class TestCore < TestInteractive
     tmux.send_keys %(echo "foo  ,bar,baz" | #{FZF} -d, --accept-nth 2,2,1,3,1 --sync --bind start:accept > #{tempname}), :Enter
     wait do
       assert_path_exists tempname
-      # Last delimiter and the whitespaces are removed
-      assert_equal ['bar,bar,foo  ,bazfoo'], File.readlines(tempname, chomp: true)
+      # Last delimiter is removed
+      assert_equal ['bar,bar,foo  ,bazfoo  '], File.readlines(tempname, chomp: true)
     end
   end
 
   def test_accept_nth_regex_delimiter
-    tmux.send_keys %(echo "foo  :,:bar,baz" | #{FZF} --delimiter='[:,]+' --accept-nth 2,2,1,3,1 --sync --bind start:accept > #{tempname}), :Enter
+    tmux.send_keys %(echo "foo  :,:bar,baz" | #{FZF} --delimiter=' *[:,]+ *' --accept-nth 2,2,1,3,1 --sync --bind start:accept > #{tempname}), :Enter
     wait do
       assert_path_exists tempname
       # Last delimiter and the whitespaces are removed
@@ -1924,7 +2349,7 @@ class TestCore < TestInteractive
   end
 
   def test_accept_nth_template
-    tmux.send_keys %(echo "foo  ,bar,baz" | #{FZF} -d, --accept-nth '[{n}] 1st: {1}, 3rd: {3}, 2nd: {2}' --sync --bind start:accept > #{tempname}), :Enter
+    tmux.send_keys %(echo "foo  ,bar,baz" | #{FZF} -d " *, *" --accept-nth '[{n}] 1st: {1}, 3rd: {3}, 2nd: {2}' --sync --bind start:accept > #{tempname}), :Enter
     wait do
       assert_path_exists tempname
       # Last delimiter and the whitespaces are removed
@@ -2176,6 +2601,80 @@ class TestCore < TestInteractive
     end
   end
 
+  def test_change_header_lines
+    tmux.send_keys %(seq 10 | #{FZF} --header-lines 3 --bind 'space:change-header-lines(5),enter:transform-header-lines(echo 1)'), :Enter
+    tmux.until do |lines|
+      assert_equal 7, lines.item_count
+      assert lines.any_include?('> 4')
+    end
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert_equal 5, lines.item_count
+      assert lines.any_include?('> 6')
+    end
+    tmux.send_keys :Enter
+    tmux.until do |lines|
+      assert_equal 9, lines.item_count
+      assert lines.any_include?('> 6')
+    end
+  end
+
+  def test_change_header_lines_to_zero
+    tmux.send_keys %(seq 5 | #{FZF} --header-lines 3 --bind 'space:bg-transform-header-lines(echo 0)'), :Enter
+    tmux.until do |lines|
+      assert_equal 2, lines.item_count
+      assert lines.any_include?('> 4')
+    end
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert_equal 5, lines.item_count
+      # All items are now in the list, cursor stays on item 4
+      assert lines.any_include?('> 4')
+    end
+  end
+
+  def test_change_header_lines_deselect
+    # Selected items that become part of the header should be deselected
+    tmux.send_keys %(seq 10 | #{FZF} --multi --header-lines 0 --bind 'space:change-header-lines(3),enter:change-header-lines(1)'), :Enter
+    tmux.until do |lines|
+      assert_equal 10, lines.item_count
+      assert lines.any_include?('> 1')
+    end
+    # Select items 1, 2, 3 (these will become header lines)
+    tmux.send_keys :BTab, :BTab, :BTab
+    tmux.until { |lines| assert_equal 3, lines.select_count }
+    # Also select item 4 (this should remain selected)
+    tmux.send_keys :BTab
+    tmux.until { |lines| assert_equal 4, lines.select_count }
+    # Change header-lines to 3: items 1, 2, 3 become headers and should be deselected
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert_equal 7, lines.item_count
+      assert_equal 1, lines.select_count
+      assert lines.any_include?('> 5')
+    end
+    # Change header-lines to 1
+    tmux.send_keys :Enter
+    tmux.until do |lines|
+      assert_equal 9, lines.item_count
+      assert_equal 1, lines.select_count
+      assert lines.any_include?('> 5')
+    end
+  end
+
+  def test_change_header_lines_reverse
+    tmux.send_keys %(seq 10 | #{FZF} --header-lines 2 --reverse --bind 'space:change-header-lines(4)'), :Enter
+    tmux.until do |lines|
+      assert_equal 8, lines.item_count
+      assert lines.any_include?('> 3')
+    end
+    tmux.send_keys :Space
+    tmux.until do |lines|
+      assert_equal 6, lines.item_count
+      assert lines.any_include?('> 5')
+    end
+  end
+
   def test_zero_width_characters
     tmux.send_keys %(for i in {1..1000}; do string+="a̱$i"; printf '\\e[43m%s\\e[0m\\n' "$string"; done | #{FZF} --ansi --query a500 --ellipsis XX), :Enter
     tmux.until do |lines|

test/test_filter.rb

@@ -326,4 +326,27 @@ class TestFilter < TestBase
     writelines(['emp001 Alice Engineering', 'emp002 Bob Marketing'])
     assert_equal 'emp001', `#{FZF} -d' ' --with-nth 2 --accept-nth 1 -f Alice < #{tempname}`.chomp
   end
+
+  def test_header_lines_filter
+    assert_equal %w[4 5 6 7 8 9 10],
+                 `seq 10 | #{FZF} --header-lines 3 -f ""`.lines(chomp: true)
+    assert_equal %w[5],
+                 `seq 10 | #{FZF} --header-lines 3 -f 5`.lines(chomp: true)
+    # Header items should not be matched
+    assert_empty `seq 10 | #{FZF} --header-lines 3 -f "^1$"`.lines(chomp: true)
+  end
+
+  def test_header_lines_filter_with_nth
+    writelines(%w[a:1 b:2 c:3 d:4 e:5])
+    assert_equal %w[c:3 d:4 e:5],
+                 `#{FZF} --header-lines 2 -d: --with-nth 2 -f "" < #{tempname}`.lines(chomp: true)
+    assert_equal %w[d:4],
+                 `#{FZF} --header-lines 2 -d: --with-nth 2 -f 4 < #{tempname}`.lines(chomp: true)
+  end
+
+  def test_header_lines_all_headers
+    # When all lines are header lines, no results
+    assert_empty `seq 3 | #{FZF} --header-lines 10 -f ""`.chomp
+    assert_equal 1, $CHILD_STATUS.exitstatus
+  end
 end

test/test_preview.rb

@@ -393,6 +393,20 @@ class TestPreview < TestInteractive
     end
   end
 
+  def test_preview_follow_wrap_long_line
+    tmux.send_keys %(seq 1 | #{FZF} --preview "seq 2; yes yes | head -10000 | tr '\n' ' '" --preview-window follow,wrap --bind up:preview-up,down:preview-down), :Enter
+    tmux.until do |lines|
+      assert_equal 1, lines.match_count
+      assert lines.any_include?('3/3 │')
+    end
+    tmux.send_keys :Up
+    tmux.until { |lines| assert lines.any_include?('2/3 │') }
+    tmux.send_keys :Up
+    tmux.until { |lines| assert lines.any_include?('1/3 │') }
+    tmux.send_keys :Down
+    tmux.until { |lines| assert lines.any_include?('2/3 │') }
+  end
+
   def test_close
     tmux.send_keys "seq 100 | #{FZF} --preview 'echo foo' --bind ctrl-c:close", :Enter
     tmux.until { |lines| assert_equal 100, lines.match_count }
@@ -593,7 +607,7 @@ class TestPreview < TestInteractive
   end
 
   def test_preview_wrap_sign_between_ansi_fragments_overflow
-    tmux.send_keys %(seq 1 | #{FZF} --preview 'echo -e "\\x1b[33m1234567890 \\x1b[mhello"; echo -e "\\x1b[33m1234567890 \\x1b[mhello"' --preview-window 2,wrap-word), :Enter
+    tmux.send_keys %(seq 1 | #{FZF} --preview 'echo -e "\\x1b[33m123 \\x1b[mhi"; echo -e "\\x1b[33m123 \\x1b[mhi"' --preview-window 2,wrap-word,noinfo), :Enter
     tmux.until do |lines|
       assert_equal 1, lines.match_count
       assert_equal(2, lines.count { |line| line.include?('│ 12 │') })
@@ -602,11 +616,27 @@ class TestPreview < TestInteractive
   end
 
   def test_preview_wrap_sign_between_ansi_fragments_overflow2
-    tmux.send_keys %(seq 1 | #{FZF} --preview 'echo -e "\\x1b[33m1234567890 \\x1b[mhello"; echo -e "\\x1b[33m1234567890 \\x1b[mhello"' --preview-window 1,wrap-word), :Enter
+    tmux.send_keys %(seq 1 | #{FZF} --preview 'echo -e "\\x1b[33m123 \\x1b[mhi"; echo -e "\\x1b[33m123 \\x1b[mhi"' --preview-window 1,wrap-word,noinfo), :Enter
     tmux.until do |lines|
       assert_equal 1, lines.match_count
       assert_equal(2, lines.count { |line| line.include?('│ 1 │') })
       assert_equal(0, lines.count { |line| line.include?('│ h') })
     end
   end
+
+  def test_preview_toggle_should_redraw_scrollbar
+    tmux.send_keys %(seq 1 | #{FZF} --no-border --scrollbar --preview 'seq $((FZF_PREVIEW_LINES + 1))' --preview-border line --bind tab:toggle-preview --header foo --header-border --footer bar --footer-border), :Enter
+    tmux.until do |lines|
+      assert_equal 1, lines.match_count
+      assert_operator lines.count { |line| line.end_with?('│') }, :>, 2
+    end
+    tmux.send_keys :Tab
+    tmux.until do |lines|
+      assert_equal(2, lines.count { |line| line.end_with?('│') })
+    end
+    tmux.send_keys :Tab
+    tmux.until do |lines|
+      assert_operator lines.count { |line| line.end_with?('│') }, :>, 2
+    end
+  end
 end

test/test_server.rb

@@ -16,6 +16,31 @@ class TestServer < TestInteractive
       assert_empty state[:query]
       assert_equal({ index: 0, text: '1' }, state[:current])
 
+      # No positions when query is empty
+      state[:matches].each do |m|
+        assert_nil m[:positions]
+      end
+      assert_nil state[:current][:positions] if state[:current]
+
+      # Positions with a single-character query
+      Net::HTTP.post(fn.call, 'change-query(1)')
+      tmux.until { |lines| assert_equal 2, lines.match_count }
+      state = JSON.parse(Net::HTTP.get(fn.call), symbolize_names: true)
+      assert_equal [0], state[:current][:positions]
+      state[:matches].each do |m|
+        assert_includes m[:text], '1'
+        assert_equal [m[:text].index('1')], m[:positions]
+      end
+
+      # Positions with a multi-character query; verify sorted ascending
+      Net::HTTP.post(fn.call, 'change-query(10)')
+      tmux.until { |lines| assert_equal 1, lines.match_count }
+      state = JSON.parse(Net::HTTP.get(fn.call), symbolize_names: true)
+      assert_equal '10', state[:current][:text]
+      assert_equal [0, 1], state[:current][:positions]
+      assert_equal state[:current][:positions], state[:current][:positions].sort
+
+      # No match — no current item
       Net::HTTP.post(fn.call, 'change-query(yo)+reload(seq 100)+change-prompt:hundred> ')
       tmux.until { |lines| assert_equal 100, lines.item_count }
       tmux.until { |lines| assert_equal 'hundred> yo', lines[-1] }

test/test_shell_integration.rb

@@ -832,6 +832,55 @@ class TestBash < TestBase
     tmux.prepare
   end
 
+  def test_ctrl_r_delete
+    tmux.prepare
+    tmux.send_keys 'echo to-keep', :Enter
+    tmux.prepare
+    tmux.send_keys 'echo to-delete-1', :Enter
+    tmux.prepare
+    tmux.send_keys 'echo to-delete-2', :Enter
+    tmux.prepare
+    tmux.send_keys 'echo to-delete-3', :Enter
+    tmux.prepare
+    tmux.send_keys 'echo another-keeper', :Enter
+    tmux.prepare
+
+    # Open Ctrl-R and delete one entry
+    tmux.send_keys 'C-r'
+    tmux.until { |lines| assert_operator lines.match_count, :>, 0 }
+    tmux.send_keys 'to-delete'
+    tmux.until { |lines| assert_equal 3, lines.match_count }
+    tmux.send_keys 'S-Delete'
+    tmux.until { |lines| assert_equal 2, lines.match_count }
+
+    # Multi-select remaining two and delete them at once
+    tmux.send_keys :BTab, :BTab
+    tmux.until { |lines| assert_includes lines[-2], '(2)' }
+    tmux.send_keys 'S-Delete'
+    tmux.until { |lines| assert_equal 0, lines.match_count }
+
+    # Exit without selecting
+    tmux.send_keys :Escape
+    tmux.prepare
+
+    # Verify deleted entries are gone from history
+    tmux.send_keys 'C-r'
+    tmux.until { |lines| assert_operator lines.match_count, :>, 0 }
+    tmux.send_keys 'to-delete'
+    tmux.until { |lines| assert_equal 0, lines.match_count }
+    tmux.send_keys :Escape
+    tmux.prepare
+
+    # Verify kept entries are still there
+    tmux.send_keys 'C-r'
+    tmux.until { |lines| assert_operator lines.match_count, :>, 0 }
+    tmux.send_keys 'to-keep'
+    tmux.until { |lines| assert_equal 1, lines.match_count }
+    tmux.send_keys :Enter
+    tmux.until { |lines| assert_equal 'echo to-keep', lines[-1] }
+    tmux.send_keys 'C-c'
+  end
+
   def test_dynamic_completion_loader
     tmux.paste 'touch /tmp/foo; _fzf_completion_loader=1'
     tmux.paste '_completion_loader() { complete -o default fake; }'
@@ -920,6 +969,7 @@ class TestZsh < TestBase
   end
 
   test_perl_and_awk 'ctrl_r_multiline_index_collision' do
+    tmux.send_keys 'setopt sh_glob', :Enter
     # Leading number in multi-line history content is not confused with index
     prepare_ctrl_r_test
     tmux.send_keys "'line 1"

typos.toml

@@ -5,6 +5,7 @@ fo = "fo"
 enew = "enew"
 tabe = "tabe"
 Iterm = "Iterm"
+ser = "ser"
 
 [files]
-extend-exclude = ["README.md"]
+extend-exclude = ["README.md", "*.s"]