0.26.0

Fix #2373

  # Display top 3 lines as the fixed header
  fzf --preview 'bat --style=header,grid --color=always {}' --preview-window '~3'

.github/workflows/linux.yml

@@ -23,16 +23,13 @@ jobs:
       with:
         go-version: ${{ matrix.go }}
 
-    - name: fish-actions/install-fish
-      uses: fish-actions/install-fish@v1.0.0
-
     - name: Setup Ruby
       uses: ruby/setup-ruby@v1.62.0
       with:
         ruby-version: 3.0.0
 
     - name: Install packages
-      run: sudo apt-get install --yes zsh tmux
+      run: sudo apt-get install --yes zsh fish tmux
 
     - name: Install Ruby gems
       run: sudo gem install --no-document minitest:5.14.2 rubocop:1.0.0 rubocop-minitest:0.10.1 rubocop-performance:1.8.1

.gon.hcl

@@ -1,11 +0,0 @@
-source = ["./dist/fzf-macos_darwin_amd64/fzf"]
-bundle_id = "kr.junegunn.fzf"
-
-apple_id {
-  username = "junegunn.c@gmail.com"
-  password = "@env:AC_PASSWORD"
-}
-
-sign {
-  application_identity = "Apple Development: junegunn.c@gmail.com"
-}

.goreleaser.yml

@@ -12,10 +12,25 @@ builds:
       - darwin
     goarch:
       - amd64
+      - arm64
     ldflags:
       - "-s -w -X main.version={{ .Version }} -X main.revision={{ .ShortCommit }}"
     hooks:
-      post: gon .gon.hcl
+      post: |-
+        sh -c '
+        cat > /tmp/fzf-gon.hcl << EOF
+        source = ["./dist/fzf-macos_darwin_{{ .Arch }}/fzf"]
+        bundle_id = "kr.junegunn.fzf"
+        apple_id {
+          username = "junegunn.c@gmail.com"
+          password = "@env:AC_PASSWORD"
+        }
+        sign {
+          application_identity = "Apple Development: junegunn.c@gmail.com"
+        }
+        EOF
+        gon /tmp/fzf-gon.hcl
+        '
 
   - goos:
       - linux

CHANGELOG.md

@@ -1,6 +1,34 @@
 CHANGELOG
 =========
 
+0.26.0
+------
+- Added support for fixed header in preview window
+  ```sh
+  # Display top 3 lines as the fixed header
+  fzf --preview 'bat --style=header,grid --color=always {}' --preview-window '~3'
+  ```
+- More advanced preview offset expression to better support the fixed header
+  ```sh
+  # Preview with bat, matching line in the middle of the window below
+  # the fixed header of the top 3 lines
+  #
+  #   ~3    Top 3 lines as the fixed header
+  #   +{2}  Base scroll offset extracted from the second field
+  #   +3    Extra offset to compensate for the 3-line header
+  #   /2    Put in the middle of the preview area
+  #
+  git grep --line-number '' |
+    fzf --delimiter : \
+        --preview 'bat --style=full --color=always --highlight-line {2} {1}' \
+        --preview-window '~3:+{2}+3/2'
+  ```
+- Added `select` and `deselect` action for unconditionally selecting or
+  deselecting a single item in `--multi` mode. Complements `toggle` action.
+- Sigificant performance improvement in ANSI code processing
+- Bug fixes and improvements
+- Built with Go 1.16
+
 0.25.1
 ------
 - Added `close` action

Makefile

@@ -66,12 +66,16 @@ endif
 all: target/$(BINARY)
 
 test: $(SOURCES)
+	[ -z "$$(gofmt -s -d src)" ] || (gofmt -s -d src; exit 1)
 	SHELL=/bin/sh GOOS= $(GO) test -v -tags "$(TAGS)" \
 				github.com/junegunn/fzf/src \
 				github.com/junegunn/fzf/src/algo \
 				github.com/junegunn/fzf/src/tui \
 				github.com/junegunn/fzf/src/util
 
+bench:
+	cd src && SHELL=/bin/sh GOOS= $(GO) test -v -tags "$(TAGS)" -run=Bench -bench=. -benchmem
+
 install: bin/fzf
 
 build:
@@ -152,4 +156,4 @@ update:
 	$(GO) get -u
 	$(GO) mod tidy
 
-.PHONY: all build release test install clean docker docker-test update
+.PHONY: all build release test bench install clean docker docker-test update

README.md

@@ -25,7 +25,7 @@ Table of Contents
 <!-- vim-markdown-toc GFM -->
 
 * [Installation](#installation)
-  * [Using Homebrew or Linuxbrew](#using-homebrew-or-linuxbrew)
+  * [Using Homebrew](#using-homebrew)
   * [Using git](#using-git)
   * [Using Linux package managers](#using-linux-package-managers)
   * [Windows](#windows)
@@ -84,9 +84,9 @@ stuff.
 
 [bin]: https://github.com/junegunn/fzf/releases
 
-### Using Homebrew or Linuxbrew
+### Using Homebrew
 
-You can use [Homebrew](http://brew.sh/) or [Linuxbrew](http://linuxbrew.sh/)
+You can use [Homebrew](http://brew.sh/) (on macOS or Linux)
 to install fzf.
 
 ```sh
@@ -411,7 +411,7 @@ unalias **<TAB>
 export FZF_COMPLETION_TRIGGER='~~'
 
 # Options to fzf command
-export FZF_COMPLETION_OPTS='+c -x'
+export FZF_COMPLETION_OPTS='--border --info=inline'
 
 # Use fd (https://github.com/sharkdp/fd) instead of the default find
 # command for listing path candidates.

bin/fzf-tmux

@@ -204,7 +204,16 @@ if [[ "$opt" =~ "-K -E" ]]; then
     cat <<< "\"$fzf\" $opts < $fifo1 > $fifo2; out=\$? $close; exit \$out" >> $argsf
     cat <&0 > $fifo1 &
   fi
-  tmux popup -d "$PWD" "${tmux_args[@]}" $opt -R "bash $argsf" > /dev/null 2>&1
+
+  # tmux dropped the support for `-K`, `-R` to popup command
+  #   TODO: We can remove this once tmux 3.2 is released
+  if [[ ! "$(tmux popup --help 2>&1)" =~ '-R shell-command' ]]; then
+    opt="${opt/-K/}"
+  else
+    opt="${opt} -R"
+  fi
+
+  tmux popup -d "$PWD" "${tmux_args[@]}" $opt "bash $argsf" > /dev/null 2>&1
   exit $?
 fi
 

go.sum

@@ -17,6 +17,7 @@ golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2 h1:VklqNMn3ovrHsnt90Pveol
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897 h1:pLI5jrR7OSLijeIDcmRxNmw2api+jEfxLoykJVice/E=
 golang.org/x/crypto v0.0.0-20201016220609-9e8e0b390897/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 h1:0GoQqolDA55aaLxZyTzK/Y2ePZzZTUrRacwib7cNsYQ=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sync v0.0.0-20200317015054-43a5402ce75a/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9 h1:SQFwaSi55rU7vdNs9Yr0Z324VNlrF+0wMqRXT4St8ck=
@@ -32,4 +33,5 @@ golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3 h1:cokOdA+Jmi5PJGXLlLllQSgYigAEfHXJAERHVMaCc2k=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e h1:FDhOuMEY4JVRztM/gsbk+IKUQ8kj74bxZrgw87eMMVc=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

install

@@ -2,7 +2,7 @@
 
 set -u
 
-version=0.25.1
+version=0.26.0
 auto_completion=
 key_bindings=
 update_config=2
@@ -168,7 +168,8 @@ archi=$(uname -sm)
 binary_available=1
 binary_error=""
 case "$archi" in
-  Darwin\ *64)     download fzf-$version-darwin_amd64.tar.gz  ;;
+# Darwin\ arm64)   download fzf-$version-darwin_arm64.tar.gz  ;; # TODO
+  Darwin\ x86_64)  download fzf-$version-darwin_amd64.tar.gz  ;;
   Linux\ armv5*)   download fzf-$version-linux_armv5.tar.gz   ;;
   Linux\ armv6*)   download fzf-$version-linux_armv6.tar.gz   ;;
   Linux\ armv7*)   download fzf-$version-linux_armv7.tar.gz   ;;

install.ps1

@@ -1,4 +1,4 @@
-$version="0.25.1"
+$version="0.26.0"
 
 $fzf_base=Split-Path -Parent $MyInvocation.MyCommand.Definition
 

main.go

@@ -5,7 +5,7 @@ import (
 	"github.com/junegunn/fzf/src/protector"
 )
 
-var version string = "0.25"
+var version string = "0.26"
 var revision string = "devel"
 
 func main() {

man/man1/fzf-tmux.1

@@ -21,7 +21,7 @@ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 ..
-.TH fzf-tmux 1 "Feb 2021" "fzf 0.25.1" "fzf-tmux - open fzf in tmux split pane"
+.TH fzf-tmux 1 "Mar 2021" "fzf 0.26.0" "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 2021" "fzf 0.25.1" "fzf - a command-line fuzzy finder"
+.TH fzf 1 "Mar 2021" "fzf 0.26.0" "fzf - a command-line fuzzy finder"
 
 .SH NAME
 fzf - a command-line fuzzy finder
@@ -442,7 +442,7 @@ e.g.
       done'\fR
 .RE
 .TP
-.BI "--preview-window=" "[POSITION][:SIZE[%]][:rounded|sharp|noborder][:[no]wrap][:[no]follow][:[no]cycle][:[no]hidden][:+SCROLL[-OFFSET]][:default]"
+.BI "--preview-window=" "[POSITION][:SIZE[%]][:rounded|sharp|noborder][:[no]wrap][:[no]follow][:[no]cycle][:[no]hidden][:+SCROLL[OFFSETS][/DENOM]][:~HEADER_LINES][:default]"
 
 .RS
 .B POSITION: (default: right)
@@ -480,12 +480,17 @@ e.g.
 \fBrounded\fR (border with rounded edges, default), \fBsharp\fR (border with
 sharp edges), or \fBnoborder\fR (no border).
 
-* \fB+SCROLL[-OFFSET]\fR determines the initial scroll offset of the preview
+* \fB[:+SCROLL[OFFSETS][/DENOM]]\fR determines the initial scroll offset of the
-window. \fBSCROLL\fR can be either a numeric integer or a single-field index
+preview window.
-expression that refers to a numeric integer. The optional \fB-OFFSET\fR part is
+
-for adjusting the base offset so that you can see the text above it. It should
+  - \fBSCROLL\fR can be either a numeric integer or a single-field index expression that refers to a numeric integer.
-be given as a numeric integer (\fB-INTEGER\fR), or as a denominator form
+
-(\fB-/INTEGER\fR) for specifying a fraction of the preview window height.
+  - The optional \fBOFFSETS\fR part is for adjusting the base offset. It should be given as a series of signed integers (\fB-INTEGER\fR or \fB+INTEGER\fR).
+
+  - The final \fB/DENOM\fR part is for specifying a fraction of the preview window height.
+
+* \fB~HEADER_LINES\fR keeps the top N lines as the fixed header so that they
+are always visible.
 
 * \fBdefault\fR resets all options previously set to the default.
 
@@ -498,14 +503,23 @@ e.g.
      # Initial scroll offset is set to the line number of each line of
      # git grep output *minus* 5 lines (-5)
      git grep --line-number '' |
-       fzf --delimiter : --preview 'nl {1}' --preview-window +{2}-5
+       fzf --delimiter : --preview 'nl {1}' --preview-window '+{2}-5'
 
-     # Preview with bat, matching line in the middle of the window (-/2)
+     # Preview with bat, matching line in the middle of the window below
+     # the fixed header of the top 3 lines
+     #
+     #   ~3    Top 3 lines as the fixed header
+     #   +{2}  Base scroll offset extracted from the second field
+     #   +3    Extra offset to compensate for the 3-line header
+     #   /2    Put in the middle of the preview area
+     #
      git grep --line-number '' |
        fzf --delimiter : \\
-           --preview 'bat --style=numbers --color=always --highlight-line {2} {1}' \\
+           --preview 'bat --style=full --color=always --highlight-line {2} {1}' \\
-           --preview-window +{2}-/2\fR
+           --preview-window '~3:+{2}+3/2'
 
+     # Display top 3 lines as the fixed header
+     fzf --preview 'bat --style=full --color=always {}' --preview-window '~3'\fR
 .RE
 
 .SS Scripting
@@ -784,6 +798,7 @@ A key or an event can be bound to one or more of the following actions.
     \fBclear-query\fR               (clear query string)
     \fBdelete-char\fR               \fIdel\fR
     \fBdelete-char/eof\fR           \fIctrl-d\fR (same as \fBdelete-char\fR except aborts fzf if query is empty)
+    \fBdeselect\fR
     \fBdeselect-all\fR              (deselect all matches)
     \fBdisable-search\fR            (disable search functionality)
     \fBdown\fR                      \fIctrl-j  ctrl-n  down\fR
@@ -819,6 +834,7 @@ A key or an event can be bound to one or more of the following actions.
     \fBrefresh-preview\fR
     \fBreload(...)\fR               (see below for the details)
     \fBreplace-query\fR             (replace query string with the current selection)
+    \fBselect\fR
     \fBselect-all\fR                (select all matches)
     \fBtoggle\fR                    (\fIright-click\fR)
     \fBtoggle-all\fR                (toggle all matches)

plugin/fzf.vim

@@ -764,6 +764,13 @@ function! s:split(dict)
   endtry
 endfunction
 
+nnoremap <silent> <Plug>(fzf-insert) i
+nnoremap <silent> <Plug>(fzf-normal) <Nop>
+if exists(':tnoremap')
+  tnoremap <silent> <Plug>(fzf-insert) <C-\><C-n>i
+  tnoremap <silent> <Plug>(fzf-normal) <C-\><C-n>
+endif
+
 function! s:execute_term(dict, command, temps) abort
   let winrest = winrestcmd()
   let pbuf = bufnr('')
@@ -776,7 +783,7 @@ function! s:execute_term(dict, command, temps) abort
   function! fzf.switch_back(inplace)
     if a:inplace && bufnr('') == self.buf
       if bufexists(self.pbuf)
-        execute 'keepalt b' self.pbuf
+        execute 'keepalt keepjumps b' self.pbuf
       endif
       " No other listed buffer
       if bufnr('') == self.buf
@@ -792,8 +799,6 @@ function! s:execute_term(dict, command, temps) abort
       call self.switch_back(1)
     else
       if bufnr('') == self.buf
-        " Exit terminal mode first (see neovim#13769)
-        call feedkeys("\<C-\>\<C-n>", 'n')
         " We use close instead of bd! since Vim does not close the split when
         " there's no other listed buffer (nvim +'set nobuflisted')
         close
@@ -818,6 +823,10 @@ function! s:execute_term(dict, command, temps) abort
     call s:pushd(self.dict)
     call s:callback(self.dict, lines)
     call self.switch_back(s:getpos() == self.ppos)
+
+    if &buftype == 'terminal'
+      call feedkeys(&filetype == 'fzf' ? "\<Plug>(fzf-insert)" : "\<Plug>(fzf-normal)")
+    endif
   endfunction
 
   try
@@ -833,7 +842,10 @@ function! s:execute_term(dict, command, temps) abort
     if has('nvim')
       call termopen(command, fzf)
     else
-      let term_opts = {'exit_cb': function(fzf.on_exit), 'term_kill': 'term'}
+      let term_opts = {'exit_cb': function(fzf.on_exit)}
+      if v:version >= 802
+        let term_opts.term_kill = 'term'
+      endif
       if is_popup
         let term_opts.hidden = 1
       else
@@ -906,13 +918,9 @@ if has('nvim')
   function s:create_popup(hl, opts) abort
     let buf = nvim_create_buf(v:false, v:true)
     let opts = extend({'relative': 'editor', 'style': 'minimal'}, a:opts)
-    let border = has_key(opts, 'border') ? remove(opts, 'border') : []
     let win = nvim_open_win(buf, v:true, opts)
     call setwinvar(win, '&winhighlight', 'NormalFloat:'..a:hl)
     call setwinvar(win, '&colorcolumn', '')
-    if !empty(border)
-      call nvim_buf_set_lines(buf, 0, -1, v:true, border)
-    endif
     return buf
   endfunction
 else

shell/key-bindings.fish

@@ -20,6 +20,7 @@ function fzf_key_bindings
     set -l commandline (__fzf_parse_commandline)
     set -l dir $commandline[1]
     set -l fzf_query $commandline[2]
+    set -l prefix $commandline[3]
 
     # "-path \$dir'*/\\.*'" matches hidden files/folders inside $dir but not
     # $dir itself, even if hidden.
@@ -42,6 +43,7 @@ function fzf_key_bindings
       commandline -t ""
     end
     for i in $result
+      commandline -it -- $prefix
       commandline -it -- (string escape $i)
       commandline -it -- ' '
     end
@@ -74,6 +76,7 @@ function fzf_key_bindings
     set -l commandline (__fzf_parse_commandline)
     set -l dir $commandline[1]
     set -l fzf_query $commandline[2]
+    set -l prefix $commandline[3]
 
     test -n "$FZF_ALT_C_COMMAND"; or set -l FZF_ALT_C_COMMAND "
     command find -L \$dir -mindepth 1 \\( -path \$dir'*/\\.*' -o -fstype 'sysfs' -o -fstype 'devfs' -o -fstype 'devtmpfs' \\) -prune \
@@ -88,6 +91,7 @@ function fzf_key_bindings
 
         # Remove last token from commandline.
         commandline -t ""
+        commandline -it -- $prefix
       end
     end
 
@@ -116,9 +120,15 @@ function fzf_key_bindings
     bind -M insert \ec fzf-cd-widget
   end
 
-  function __fzf_parse_commandline -d 'Parse the current command line token and return split of existing filepath and rest of token'
+  function __fzf_parse_commandline -d 'Parse the current command line token and return split of existing filepath, fzf query, and optional -option= prefix'
+    set -l commandline (commandline -t)
+
+    # strip -option= from token if present
+    set -l prefix (string match -r -- '^-[^\s=]+=' $commandline)
+    set commandline (string replace -- "$prefix" '' $commandline)
+
     # eval is used to do shell expansion on paths
-    set -l commandline (eval "printf '%s' "(commandline -t))
+    eval set commandline $commandline
 
     if [ -z $commandline ]
       # Default to current directory with no --query
@@ -138,6 +148,7 @@ function fzf_key_bindings
 
     echo $dir
     echo $fzf_query
+    echo $prefix
   end
 
   function __fzf_get_dir -d 'Find the longest existing filepath from input string'

src/ansi.go

@@ -1,8 +1,6 @@
 package fzf
 
 import (
-	"bytes"
-	"regexp"
 	"strconv"
 	"strings"
 	"unicode/utf8"
@@ -82,73 +80,154 @@ func toAnsiString(color tui.Color, offset int) string {
 	return ret + ";"
 }
 
-var ansiRegex *regexp.Regexp
+func isPrint(c uint8) bool {
-
+	return '\x20' <= c && c <= '\x7e'
-func init() {
-	/*
-		References:
-		- https://github.com/gnachman/iTerm2
-		- http://ascii-table.com/ansi-escape-sequences.php
-		- http://ascii-table.com/ansi-escape-sequences-vt-100.php
-		- http://tldp.org/HOWTO/Bash-Prompt-HOWTO/x405.html
-		- https://invisible-island.net/xterm/ctlseqs/ctlseqs.html
-	*/
-	// The following regular expression will include not all but most of the
-	// frequently used ANSI sequences
-	ansiRegex = regexp.MustCompile("(?:\x1b[\\[()][0-9;]*[a-zA-Z@]|\x1b][0-9];[[:print:]]+(?:\x1b\\\\|\x07)|\x1b.|[\x0e\x0f]|.\x08)")
 }
 
-func findAnsiStart(str string) int {
+func matchOperatingSystemCommand(s string) int {
-	idx := 0
+	// `\x1b][0-9];[[:print:]]+(?:\x1b\\\\|\x07)`
-	for ; idx < len(str); idx++ {
+	//                        ^ match starting here
-		b := str[idx]
+	//
-		if b == 0x1b || b == 0x0e || b == 0x0f {
+	i := 5 // prefix matched in nextAnsiEscapeSequence()
-			return idx
+	for ; i < len(s) && isPrint(s[i]); i++ {
 	}
-		if b == 0x08 && idx > 0 {
+	if i < len(s) {
-			return idx - 1
+		if s[i] == '\x07' {
+			return i + 1
+		}
+		if s[i] == '\x1b' && i < len(s)-1 && s[i+1] == '\\' {
+			return i + 2
 		}
 	}
-	return idx
+	return -1
+}
+
+func matchControlSequence(s string) int {
+	// `\x1b[\\[()][0-9;]*[a-zA-Z@]`
+	//                   ^ match starting here
+	//
+	i := 2 // prefix matched in nextAnsiEscapeSequence()
+	for ; i < len(s) && (isNumeric(s[i]) || s[i] == ';'); i++ {
+	}
+	if i < len(s) {
+		c := s[i]
+		if 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' || c == '@' {
+			return i + 1
+		}
+	}
+	return -1
+}
+
+func isCtrlSeqStart(c uint8) bool {
+	return c == '\\' || c == '[' || c == '(' || c == ')'
+}
+
+// nextAnsiEscapeSequence returns the ANSI escape sequence and is equivalent to
+// calling FindStringIndex() on the below regex (which was originally used):
+//
+// "(?:\x1b[\\[()][0-9;]*[a-zA-Z@]|\x1b][0-9];[[:print:]]+(?:\x1b\\\\|\x07)|\x1b.|[\x0e\x0f]|.\x08)"
+//
+func nextAnsiEscapeSequence(s string) (int, int) {
+	// fast check for ANSI escape sequences
+	i := 0
+	for ; i < len(s); i++ {
+		switch s[i] {
+		case '\x0e', '\x0f', '\x1b', '\x08':
+			// We ignore the fact that '\x08' cannot be the first char
+			// in the string and be an escape sequence for the sake of
+			// speed and simplicity.
+			goto Loop
+		}
+	}
+	return -1, -1
+
+Loop:
+	for ; i < len(s); i++ {
+		switch s[i] {
+		case '\x08':
+			// backtrack to match: `.\x08`
+			if i > 0 && s[i-1] != '\n' {
+				if s[i-1] < utf8.RuneSelf {
+					return i - 1, i + 1
+				}
+				_, n := utf8.DecodeLastRuneInString(s[:i])
+				return i - n, i + 1
+			}
+		case '\x1b':
+			// match: `\x1b[\\[()][0-9;]*[a-zA-Z@]`
+			if i+2 < len(s) && isCtrlSeqStart(s[i+1]) {
+				if j := matchControlSequence(s[i:]); j != -1 {
+					return i, i + j
+				}
+			}
+
+			// match: `\x1b][0-9];[[:print:]]+(?:\x1b\\\\|\x07)`
+			if i+5 < len(s) && s[i+1] == ']' && isNumeric(s[i+2]) &&
+				s[i+3] == ';' && isPrint(s[i+4]) {
+
+				if j := matchOperatingSystemCommand(s[i:]); j != -1 {
+					return i, i + j
+				}
+			}
+
+			// match: `\x1b.`
+			if i+1 < len(s) && s[i+1] != '\n' {
+				if s[i+1] < utf8.RuneSelf {
+					return i, i + 2
+				}
+				_, n := utf8.DecodeRuneInString(s[i+1:])
+				return i, i + n + 1
+			}
+		case '\x0e', '\x0f':
+			// match: `[\x0e\x0f]`
+			return i, i + 1
+		}
+	}
+	return -1, -1
 }
 
 func extractColor(str string, state *ansiState, proc func(string, *ansiState) bool) (string, *[]ansiOffset, *ansiState) {
-	var offsets []ansiOffset
+	// We append to a stack allocated variable that we'll
-	var output bytes.Buffer
+	// later copy and return, to save on allocations.
+	offsets := make([]ansiOffset, 0, 32)
 
 	if state != nil {
 		offsets = append(offsets, ansiOffset{[2]int32{0, 0}, *state})
 	}
 
-	prevIdx := 0
+	var (
-	runeCount := 0
+		pstate    *ansiState // lazily allocated
+		output    strings.Builder
+		prevIdx   int
+		runeCount int
+	)
 	for idx := 0; idx < len(str); {
-		idx += findAnsiStart(str[idx:])
+		// Make sure that we found an ANSI code
-		if idx == len(str) {
+		start, end := nextAnsiEscapeSequence(str[idx:])
+		if start == -1 {
 			break
 		}
-
+		start += idx
-		// Make sure that we found an ANSI code
+		idx += end
-		offset := ansiRegex.FindStringIndex(str[idx:])
-		if len(offset) < 2 {
-			idx++
-			continue
-		}
-		offset[0] += idx
-		offset[1] += idx
-		idx = offset[1]
 
 		// Check if we should continue
-		prev := str[prevIdx:offset[0]]
+		prev := str[prevIdx:start]
 		if proc != nil && !proc(prev, state) {
 			return "", nil, nil
 		}
+		prevIdx = idx
 
-		prevIdx = offset[1]
+		if len(prev) != 0 {
 			runeCount += utf8.RuneCountInString(prev)
+			// Grow the buffer size to the maximum possible length (string length
+			// containing ansi codes) to avoid repetitive allocation
+			if output.Cap() == 0 {
+				output.Grow(len(str))
+			}
 			output.WriteString(prev)
+		}
 
-		newState := interpretCode(str[offset[0]:offset[1]], state)
+		newState := interpretCode(str[start:idx], state)
 		if !newState.equals(state) {
 			if state != nil {
 				// Update last offset
@@ -157,8 +236,15 @@ func extractColor(str string, state *ansiState, proc func(string, *ansiState) bo
 
 			if newState.colored() {
 				// Append new offset
-				state = newState
+				if pstate == nil {
-				offsets = append(offsets, ansiOffset{[2]int32{int32(runeCount), int32(runeCount)}, *state})
+					pstate = &ansiState{}
+				}
+				*pstate = newState
+				state = pstate
+				offsets = append(offsets, ansiOffset{
+					[2]int32{int32(runeCount), int32(runeCount)},
+					newState,
+				})
 			} else {
 				// Discard state
 				state = nil
@@ -168,7 +254,6 @@ func extractColor(str string, state *ansiState, proc func(string, *ansiState) bo
 
 	var rest string
 	var trimmed string
-
 	if prevIdx == 0 {
 		// No ANSI code found
 		rest = str
@@ -178,51 +263,75 @@ func extractColor(str string, state *ansiState, proc func(string, *ansiState) bo
 		output.WriteString(rest)
 		trimmed = output.String()
 	}
+	if proc != nil {
+		proc(rest, state)
+	}
+	if len(offsets) > 0 {
 		if len(rest) > 0 && state != nil {
 			// Update last offset
 			runeCount += utf8.RuneCountInString(rest)
 			(&offsets[len(offsets)-1]).offset[1] = int32(runeCount)
 		}
-	if proc != nil {
+		// Return a copy of the offsets slice
-		proc(rest, state)
+		a := make([]ansiOffset, len(offsets))
+		copy(a, offsets)
+		return trimmed, &a, state
 	}
-	if len(offsets) == 0 {
 	return trimmed, nil, state
 }
-	return trimmed, &offsets, state
+
+func parseAnsiCode(s string) (int, string) {
+	var remaining string
+	if i := strings.IndexByte(s, ';'); i >= 0 {
+		remaining = s[i+1:]
+		s = s[:i]
 	}
 
-func interpretCode(ansiCode string, prevState *ansiState) *ansiState {
+	if len(s) > 0 {
-	// State
+		// Inlined version of strconv.Atoi() that only handles positive
-	var state *ansiState
+		// integers and does not allocate on error.
+		code := 0
+		for _, ch := range []byte(s) {
+			ch -= '0'
+			if ch > 9 {
+				return -1, remaining
+			}
+			code = code*10 + int(ch)
+		}
+		return code, remaining
+	}
+
+	return -1, remaining
+}
+
+func interpretCode(ansiCode string, prevState *ansiState) ansiState {
+	var state ansiState
 	if prevState == nil {
-		state = &ansiState{-1, -1, 0, -1}
+		state = ansiState{-1, -1, 0, -1}
 	} else {
-		state = &ansiState{prevState.fg, prevState.bg, prevState.attr, prevState.lbg}
+		state = ansiState{prevState.fg, prevState.bg, prevState.attr, prevState.lbg}
 	}
 	if ansiCode[0] != '\x1b' || ansiCode[1] != '[' || ansiCode[len(ansiCode)-1] != 'm' {
-		if strings.HasSuffix(ansiCode, "0K") && prevState != nil {
+		if prevState != nil && strings.HasSuffix(ansiCode, "0K") {
 			state.lbg = prevState.bg
 		}
 		return state
 	}
 
-	ptr := &state.fg
+	if len(ansiCode) <= 3 {
-	state256 := 0
-
-	init := func() {
 		state.fg = -1
 		state.bg = -1
 		state.attr = 0
-		state256 = 0
+		return state
 	}
-
 	ansiCode = ansiCode[2 : len(ansiCode)-1]
-	if len(ansiCode) == 0 {
+
-		init()
+	state256 := 0
-	}
+	ptr := &state.fg
-	for _, code := range strings.Split(ansiCode, ";") {
+
-		if num, err := strconv.Atoi(code); err == nil {
+	for len(ansiCode) != 0 {
+		var num int
+		if num, ansiCode = parseAnsiCode(ansiCode); num != -1 {
 			switch state256 {
 			case 0:
 				switch num {
@@ -253,7 +362,10 @@ func interpretCode(ansiCode string, prevState *ansiState) *ansiState {
 				case 24: // tput rmul
 					state.attr = state.attr &^ tui.Underline
 				case 0:
-					init()
+					state.fg = -1
+					state.bg = -1
+					state.attr = 0
+					state256 = 0
 				default:
 					if num >= 30 && num <= 37 {
 						state.fg = tui.Color(num - 30)
@@ -289,6 +401,7 @@ func interpretCode(ansiCode string, prevState *ansiState) *ansiState {
 			}
 		}
 	}
+
 	if state256 > 0 {
 		*ptr = -1
 	}

src/ansi_test.go

@@ -2,12 +2,190 @@ package fzf
 
 import (
 	"fmt"
+	"math/rand"
+	"regexp"
 	"strings"
 	"testing"
+	"unicode/utf8"
 
 	"github.com/junegunn/fzf/src/tui"
 )
 
+// The following regular expression will include not all but most of the
+// frequently used ANSI sequences. This regex is used as a reference for
+// testing nextAnsiEscapeSequence().
+//
+// References:
+// 	- https://github.com/gnachman/iTerm2
+// 	- http://ascii-table.com/ansi-escape-sequences.php
+// 	- http://ascii-table.com/ansi-escape-sequences-vt-100.php
+// 	- http://tldp.org/HOWTO/Bash-Prompt-HOWTO/x405.html
+// 	- https://invisible-island.net/xterm/ctlseqs/ctlseqs.html
+var ansiRegexRefence = regexp.MustCompile("(?:\x1b[\\[()][0-9;]*[a-zA-Z@]|\x1b][0-9];[[:print:]]+(?:\x1b\\\\|\x07)|\x1b.|[\x0e\x0f]|.\x08)")
+
+func testParserReference(t testing.TB, str string) {
+	t.Helper()
+
+	toSlice := func(start, end int) []int {
+		if start == -1 {
+			return nil
+		}
+		return []int{start, end}
+	}
+
+	s := str
+	for i := 0; ; i++ {
+		got := toSlice(nextAnsiEscapeSequence(s))
+		exp := ansiRegexRefence.FindStringIndex(s)
+
+		equal := len(got) == len(exp)
+		if equal {
+			for i := 0; i < len(got); i++ {
+				if got[i] != exp[i] {
+					equal = false
+					break
+				}
+			}
+		}
+		if !equal {
+			var exps, gots []rune
+			if len(got) == 2 {
+				gots = []rune(s[got[0]:got[1]])
+			}
+			if len(exp) == 2 {
+				exps = []rune(s[exp[0]:exp[1]])
+			}
+			t.Errorf("%d: %q: got: %v (%q) want: %v (%q)", i, s, got, gots, exp, exps)
+			return
+		}
+		if len(exp) == 0 {
+			return
+		}
+		s = s[exp[1]:]
+	}
+}
+
+func TestNextAnsiEscapeSequence(t *testing.T) {
+	testStrs := []string{
+		"\x1b[0mhello world",
+		"\x1b[1mhello world",
+		"椙\x1b[1m椙",
+		"椙\x1b[1椙m椙",
+		"\x1b[1mhello \x1b[mw\x1b7o\x1b8r\x1b(Bl\x1b[2@d",
+		"\x1b[1mhello \x1b[Kworld",
+		"hello \x1b[34;45;1mworld",
+		"hello \x1b[34;45;1mwor\x1b[34;45;1mld",
+		"hello \x1b[34;45;1mwor\x1b[0mld",
+		"hello \x1b[34;48;5;233;1mwo\x1b[38;5;161mr\x1b[0ml\x1b[38;5;161md",
+		"hello \x1b[38;5;38;48;5;48;1mwor\x1b[38;5;48;48;5;38ml\x1b[0md",
+		"hello \x1b[32;1mworld",
+		"hello world",
+		"hello \x1b[0;38;5;200;48;5;100mworld",
+		"\x1b椙",
+		"椙\x08",
+		"\n\x08",
+		"X\x08",
+		"",
+		"\x1b]4;3;rgb:aa/bb/cc\x07 ",
+		"\x1b]4;3;rgb:aa/bb/cc\x1b\\ ",
+		ansiBenchmarkString,
+	}
+
+	for _, s := range testStrs {
+		testParserReference(t, s)
+	}
+}
+
+func TestNextAnsiEscapeSequence_Fuzz_Modified(t *testing.T) {
+	t.Parallel()
+	if testing.Short() {
+		t.Skip("short test")
+	}
+
+	testStrs := []string{
+		"\x1b[0mhello world",
+		"\x1b[1mhello world",
+		"椙\x1b[1m椙",
+		"椙\x1b[1椙m椙",
+		"\x1b[1mhello \x1b[mw\x1b7o\x1b8r\x1b(Bl\x1b[2@d",
+		"\x1b[1mhello \x1b[Kworld",
+		"hello \x1b[34;45;1mworld",
+		"hello \x1b[34;45;1mwor\x1b[34;45;1mld",
+		"hello \x1b[34;45;1mwor\x1b[0mld",
+		"hello \x1b[34;48;5;233;1mwo\x1b[38;5;161mr\x1b[0ml\x1b[38;5;161md",
+		"hello \x1b[38;5;38;48;5;48;1mwor\x1b[38;5;48;48;5;38ml\x1b[0md",
+		"hello \x1b[32;1mworld",
+		"hello world",
+		"hello \x1b[0;38;5;200;48;5;100mworld",
+		ansiBenchmarkString,
+	}
+
+	replacementBytes := [...]rune{'\x0e', '\x0f', '\x1b', '\x08'}
+
+	modifyString := func(s string, rr *rand.Rand) string {
+		n := rr.Intn(len(s))
+		b := []rune(s)
+		for ; n >= 0 && len(b) != 0; n-- {
+			i := rr.Intn(len(b))
+			switch x := rr.Intn(4); x {
+			case 0:
+				b = append(b[:i], b[i+1:]...)
+			case 1:
+				j := rr.Intn(len(replacementBytes) - 1)
+				b[i] = replacementBytes[j]
+			case 2:
+				x := rune(rr.Intn(utf8.MaxRune))
+				for !utf8.ValidRune(x) {
+					x = rune(rr.Intn(utf8.MaxRune))
+				}
+				b[i] = x
+			case 3:
+				b[i] = rune(rr.Intn(utf8.MaxRune)) // potentially invalid
+			default:
+				t.Fatalf("unsupported value: %d", x)
+			}
+		}
+		return string(b)
+	}
+
+	rr := rand.New(rand.NewSource(1))
+	for _, s := range testStrs {
+		for i := 1_000; i >= 0; i-- {
+			testParserReference(t, modifyString(s, rr))
+		}
+	}
+}
+
+func TestNextAnsiEscapeSequence_Fuzz_Random(t *testing.T) {
+	t.Parallel()
+
+	if testing.Short() {
+		t.Skip("short test")
+	}
+
+	randomString := func(rr *rand.Rand) string {
+		numChars := rand.Intn(50)
+		codePoints := make([]rune, numChars)
+		for i := 0; i < len(codePoints); i++ {
+			var r rune
+			for n := 0; n < 1000; n++ {
+				r = rune(rr.Intn(utf8.MaxRune))
+				// Allow 10% of runes to be invalid
+				if utf8.ValidRune(r) || rr.Float64() < 0.10 {
+					break
+				}
+			}
+			codePoints[i] = r
+		}
+		return string(codePoints)
+	}
+
+	rr := rand.New(rand.NewSource(1))
+	for i := 0; i < 100_000; i++ {
+		testParserReference(t, randomString(rr))
+	}
+}
+
 func TestExtractColor(t *testing.T) {
 	assert := func(offset ansiOffset, b int32, e int32, fg tui.Color, bg tui.Color, bold bool) {
 		var attr tui.Attr
@@ -185,3 +363,64 @@ func TestAnsiCodeStringConversion(t *testing.T) {
 		&ansiState{attr: tui.Dim | tui.Italic, fg: 1, bg: 1},
 		"\x1b[2;3;7;38;2;10;20;30;48;5;100m")
 }
+
+func TestParseAnsiCode(t *testing.T) {
+	tests := []struct {
+		In, Exp string
+		N       int
+	}{
+		{"123", "", 123},
+		{"1a", "", -1},
+		{"1a;12", "12", -1},
+		{"12;a", "a", 12},
+		{"-2", "", -1},
+	}
+	for _, x := range tests {
+		n, s := parseAnsiCode(x.In)
+		if n != x.N || s != x.Exp {
+			t.Fatalf("%q: got: (%d %q) want: (%d %q)", x.In, n, s, x.N, x.Exp)
+		}
+	}
+}
+
+// kernel/bpf/preload/iterators/README
+const ansiBenchmarkString = "\x1b[38;5;81m\x1b[01;31m\x1b[Kkernel/\x1b[0m\x1b[38;5;81mbpf/" +
+	"\x1b[0m\x1b[38;5;81mpreload/\x1b[0m\x1b[38;5;81miterators/" +
+	"\x1b[0m\x1b[38;5;149mMakefile\x1b[m\x1b[K\x1b[0m"
+
+func BenchmarkNextAnsiEscapeSequence(b *testing.B) {
+	b.SetBytes(int64(len(ansiBenchmarkString)))
+	for i := 0; i < b.N; i++ {
+		s := ansiBenchmarkString
+		for {
+			_, o := nextAnsiEscapeSequence(s)
+			if o == -1 {
+				break
+			}
+			s = s[o:]
+		}
+	}
+}
+
+// Baseline test to compare the speed of nextAnsiEscapeSequence() to the
+// previously used regex based implementation.
+func BenchmarkNextAnsiEscapeSequence_Regex(b *testing.B) {
+	b.SetBytes(int64(len(ansiBenchmarkString)))
+	for i := 0; i < b.N; i++ {
+		s := ansiBenchmarkString
+		for {
+			a := ansiRegexRefence.FindStringIndex(s)
+			if len(a) == 0 {
+				break
+			}
+			s = s[a[1]:]
+		}
+	}
+}
+
+func BenchmarkExtractColor(b *testing.B) {
+	b.SetBytes(int64(len(ansiBenchmarkString)))
+	for i := 0; i < b.N; i++ {
+		extractColor(ansiBenchmarkString, nil, nil)
+	}
+}

src/cache_test.go

@@ -6,8 +6,8 @@ func TestChunkCache(t *testing.T) {
 	cache := NewChunkCache()
 	chunk1p := &Chunk{}
 	chunk2p := &Chunk{count: chunkSize}
-	items1 := []Result{Result{}}
+	items1 := []Result{{}}
-	items2 := []Result{Result{}, Result{}}
+	items2 := []Result{{}, {}}
 	cache.Add(chunk1p, "foo", items1)
 	cache.Add(chunk2p, "foo", items1)
 	cache.Add(chunk2p, "bar", items2)

src/constants.go

@@ -73,6 +73,7 @@ const (
 	EvtSearchFin
 	EvtHeader
 	EvtReady
+	EvtQuit
 )
 
 const (

src/core.go

@@ -254,7 +254,11 @@ func Run(opts *Options, version string, revision string) {
 			}
 			for evt, value := range *events {
 				switch evt {
-
+				case EvtQuit:
+					if reading {
+						reader.terminate()
+					}
+					os.Exit(value.(int))
 				case EvtReadNew, EvtReadFin:
 					if evt == EvtReadFin && nextCommand != nil {
 						restart(*nextCommand)

src/merger.go

@@ -106,7 +106,6 @@ func (mg *Merger) mergedGet(idx int) Result {
 					minIdx = listIdx
 				}
 			}
-			mg.cursors[listIdx] = cursor
 		}
 
 		if minIdx >= 0 {

src/options.go

@@ -84,7 +84,7 @@ const usage = `usage: fzf [options]
                           [up|down|left|right][:SIZE[%]]
                           [:[no]wrap][:[no]cycle][:[no]follow][:[no]hidden]
                           [:rounded|sharp|noborder]
-                          [:+SCROLL[-OFFSET]]
+                          [:+SCROLL[OFFSETS][/DENOM]][:~HEADER_LINES]
                           [:default]
 
   Scripting
@@ -170,6 +170,7 @@ type previewOpts struct {
 	cycle       bool
 	follow      bool
 	border      tui.BorderShape
+	headerLines int
 }
 
 // Options stores the values of command-line options
@@ -231,7 +232,7 @@ type Options struct {
 }
 
 func defaultPreviewOpts(command string) previewOpts {
-	return previewOpts{command, posRight, sizeSpec{50, true}, "", false, false, false, false, tui.BorderRounded}
+	return previewOpts{command, posRight, sizeSpec{50, true}, "", false, false, false, false, tui.BorderRounded, 0}
 }
 
 func defaultOptions() *Options {
@@ -839,6 +840,8 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 				appendAction(actDeleteChar)
 			case "delete-char/eof":
 				appendAction(actDeleteCharEOF)
+			case "deselect":
+				appendAction(actDeselect)
 			case "end-of-line":
 				appendAction(actEndOfLine)
 			case "cancel":
@@ -879,6 +882,8 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 				appendAction(actToggleAll)
 			case "toggle-search":
 				appendAction(actToggleSearch)
+			case "select":
+				appendAction(actSelect)
 			case "select-all":
 				appendAction(actSelectAll)
 			case "deselect-all":
@@ -1073,7 +1078,8 @@ func parseInfoStyle(str string) infoStyle {
 func parsePreviewWindow(opts *previewOpts, input string) {
 	tokens := strings.Split(input, ":")
 	sizeRegex := regexp.MustCompile("^[0-9]+%?$")
-	offsetRegex := regexp.MustCompile("^\\+([0-9]+|{-?[0-9]+})(-[0-9]+|-/[1-9][0-9]*)?$")
+	offsetRegex := regexp.MustCompile(`^(\+{-?[0-9]+})?([+-][0-9]+)*(-?/[1-9][0-9]*)?$`)
+	headerRegex := regexp.MustCompile("^~(0|[1-9][0-9]*)$")
 	for _, token := range tokens {
 		switch token {
 		case "":
@@ -1110,10 +1116,12 @@ func parsePreviewWindow(opts *previewOpts, input string) {
 		case "nofollow":
 			opts.follow = false
 		default:
-			if sizeRegex.MatchString(token) {
+			if headerRegex.MatchString(token) {
+				opts.headerLines = atoi(token[1:])
+			} else if sizeRegex.MatchString(token) {
 				opts.size = parseSize(token, 99, "window size")
 			} else if offsetRegex.MatchString(token) {
-				opts.scroll = token[1:]
+				opts.scroll = token
 			} else {
 				errorExit("invalid preview window option: " + token)
 			}
@@ -1360,7 +1368,7 @@ func parseOptions(opts *Options, allArgs []string) {
 			opts.Preview.command = ""
 		case "--preview-window":
 			parsePreviewWindow(&opts.Preview,
-				nextString(allArgs, &i, "preview window layout required: [up|down|left|right][:SIZE[%]][:rounded|sharp|noborder][:wrap][:cycle][:hidden][:+SCROLL[-OFFSET]][:default]"))
+				nextString(allArgs, &i, "preview window layout required: [up|down|left|right][:SIZE[%]][:rounded|sharp|noborder][:wrap][:cycle][:hidden][:+SCROLL[OFFSETS][/DENOM]][:~HEADER_LINES][:default]"))
 		case "--height":
 			opts.Height = parseHeight(nextString(allArgs, &i, "height required: HEIGHT[%]"))
 		case "--min-height":

src/options_test.go

@@ -102,7 +102,7 @@ func TestIrrelevantNth(t *testing.T) {
 			t.Errorf("nth should be empty: %v", opts.Nth)
 		}
 	}
-	for _, words := range [][]string{[]string{"--nth", "..,3", "+x"}, []string{"--nth", "3,1..", "+x"}, []string{"--nth", "..-1,1", "+x"}} {
+	for _, words := range [][]string{{"--nth", "..,3", "+x"}, {"--nth", "3,1..", "+x"}, {"--nth", "..-1,1", "+x"}} {
 		{
 			opts := defaultOptions()
 			parseOptions(opts, words)
@@ -389,18 +389,18 @@ func TestPreviewOpts(t *testing.T) {
 		opts.Preview.hidden == true &&
 		opts.Preview.wrap == true &&
 		opts.Preview.position == posLeft &&
-		opts.Preview.scroll == "{1}-/2" &&
+		opts.Preview.scroll == "+{1}-/2" &&
 		opts.Preview.size.percent == false &&
 		opts.Preview.size.size == 15) {
 		t.Error(opts.Preview)
 	}
-	opts = optsFor("--preview-window=up:15:wrap:hidden:+{1}-/2", "--preview-window=down", "--preview-window=cycle")
+	opts = optsFor("--preview-window=up:15:wrap:hidden:+{1}+3-1-2/2", "--preview-window=down", "--preview-window=cycle")
 	if !(opts.Preview.command == "" &&
 		opts.Preview.hidden == true &&
 		opts.Preview.wrap == true &&
 		opts.Preview.cycle == true &&
 		opts.Preview.position == posDown &&
-		opts.Preview.scroll == "{1}-/2" &&
+		opts.Preview.scroll == "+{1}+3-1-2/2" &&
 		opts.Preview.size.percent == false &&
 		opts.Preview.size.size == 15) {
 		t.Error(opts.Preview.size.size)

src/pattern.go

@@ -337,7 +337,7 @@ func (p *Pattern) MatchItem(item *Item, withPos bool, slab *util.Slab) (*Result,
 func (p *Pattern) basicMatch(item *Item, withPos bool, slab *util.Slab) (Offset, int, *[]int) {
 	var input []Token
 	if len(p.nth) == 0 {
-		input = []Token{Token{text: &item.text, prefixLength: 0}}
+		input = []Token{{text: &item.text, prefixLength: 0}}
 	} else {
 		input = p.transformInput(item)
 	}
@@ -350,7 +350,7 @@ func (p *Pattern) basicMatch(item *Item, withPos bool, slab *util.Slab) (Offset,
 func (p *Pattern) extendedMatch(item *Item, withPos bool, slab *util.Slab) ([]Offset, int, *[]int) {
 	var input []Token
 	if len(p.nth) == 0 {
-		input = []Token{Token{text: &item.text, prefixLength: 0}}
+		input = []Token{{text: &item.text, prefixLength: 0}}
 	} else {
 		input = p.transformInput(item)
 	}

src/pattern_test.go

@@ -131,7 +131,7 @@ func TestCaseSensitivity(t *testing.T) {
 func TestOrigTextAndTransformed(t *testing.T) {
 	pattern := BuildPattern(true, algo.FuzzyMatchV2, true, CaseSmart, false, true, true, []Range{}, Delimiter{}, []rune("jg"))
 	tokens := Tokenize("junegunn", Delimiter{})
-	trans := Transform(tokens, []Range{Range{1, 1}})
+	trans := Transform(tokens, []Range{{1, 1}})
 
 	origBytes := []byte("junegunn.choi")
 	for _, extended := range []bool{false, true} {

src/result_test.go

@@ -18,8 +18,8 @@ func withIndex(i *Item, index int) *Item {
 
 func TestOffsetSort(t *testing.T) {
 	offsets := []Offset{
-		Offset{3, 5}, Offset{2, 7},
+		{3, 5}, {2, 7},
-		Offset{1, 3}, Offset{2, 9}}
+		{1, 3}, {2, 9}}
 	sort.Sort(ByOrder(offsets))
 
 	if offsets[0][0] != 1 || offsets[0][1] != 3 ||
@@ -84,13 +84,13 @@ func TestResultRank(t *testing.T) {
 
 	// Sort by relevance
 	item3 := buildResult(
-		withIndex(&Item{}, 2), []Offset{Offset{1, 3}, Offset{5, 7}}, 3)
+		withIndex(&Item{}, 2), []Offset{{1, 3}, {5, 7}}, 3)
 	item4 := buildResult(
-		withIndex(&Item{}, 2), []Offset{Offset{1, 2}, Offset{6, 7}}, 4)
+		withIndex(&Item{}, 2), []Offset{{1, 2}, {6, 7}}, 4)
 	item5 := buildResult(
-		withIndex(&Item{}, 2), []Offset{Offset{1, 3}, Offset{5, 7}}, 5)
+		withIndex(&Item{}, 2), []Offset{{1, 3}, {5, 7}}, 5)
 	item6 := buildResult(
-		withIndex(&Item{}, 2), []Offset{Offset{1, 2}, Offset{6, 7}}, 6)
+		withIndex(&Item{}, 2), []Offset{{1, 2}, {6, 7}}, 6)
 	items = []Result{item1, item2, item3, item4, item5, item6}
 	sort.Sort(ByRelevance(items))
 	if !(items[0] == item6 && items[1] == item5 &&

src/terminal.go

@@ -22,8 +22,9 @@ import (
 // import "github.com/pkg/profile"
 
 var placeholder *regexp.Regexp
-var numericPrefix *regexp.Regexp
 var whiteSuffix *regexp.Regexp
+var offsetComponentRegex *regexp.Regexp
+var offsetTrimCharsRegex *regexp.Regexp
 var activeTempFiles []string
 
 const ellipsis string = ".."
@@ -31,8 +32,9 @@ const clearCode string = "\x1b[2J"
 
 func init() {
 	placeholder = regexp.MustCompile(`\\?(?:{[+sf]*[0-9,-.]*}|{q}|{\+?f?nf?})`)
-	numericPrefix = regexp.MustCompile(`^[[:punct:]]*([0-9]+)`)
 	whiteSuffix = regexp.MustCompile(`\s*$`)
+	offsetComponentRegex = regexp.MustCompile(`([+-][0-9]+)|(-?/[1-9][0-9]*)`)
+	offsetTrimCharsRegex = regexp.MustCompile(`[^0-9/+-]`)
 	activeTempFiles = []string{}
 }
 
@@ -133,6 +135,7 @@ type Terminal struct {
 	count        int
 	progress     int
 	reading      bool
+	running      bool
 	failed       *string
 	jumping      jumpMode
 	jumpLabels   string
@@ -157,6 +160,7 @@ type Terminal struct {
 	slab         *util.Slab
 	theme        *tui.ColorTheme
 	tui          tui.Renderer
+	executing    *util.AtomicBool
 }
 
 type selectedItem struct {
@@ -276,6 +280,8 @@ const (
 	actReload
 	actDisableSearch
 	actEnableSearch
+	actSelect
+	actDeselect
 )
 
 type placeholderFlags struct {
@@ -502,6 +508,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		ansi:        opts.Ansi,
 		tabstop:     opts.Tabstop,
 		reading:     true,
+		running:     true,
 		failed:      nil,
 		jumping:     jumpDisabled,
 		jumpLabels:  opts.JumpLabels,
@@ -523,7 +530,8 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		startChan:   make(chan bool, 1),
 		killChan:    make(chan int),
 		tui:         renderer,
-		initFunc:    func() { renderer.Init() }}
+		initFunc:    func() { renderer.Init() },
+		executing:   util.NewAtomicBool(false)}
 	t.prompt, t.promptLen = t.parsePrompt(opts.Prompt)
 	t.pointer, t.pointerLen = t.processTabs([]rune(opts.Pointer), 0)
 	t.marker, t.markerLen = t.processTabs([]rune(opts.Marker), 0)
@@ -1140,8 +1148,8 @@ func (t *Terminal) trimLeft(runes []rune, width int) ([]rune, int32) {
 	width = util.Max(0, width)
 	var trimmed int32
 	// Assume that each rune takes at least one column on screen
-	if len(runes) > width {
+	if len(runes) > width+2 {
-		diff := len(runes) - width
+		diff := len(runes) - width - 2
 		trimmed = int32(diff)
 		runes = runes[diff:]
 	}
@@ -1289,18 +1297,37 @@ func (t *Terminal) renderPreviewSpinner() {
 	}
 }
 
-func (t *Terminal) renderPreviewText(unchanged bool) {
+func (t *Terminal) renderPreviewArea(unchanged bool) {
-	maxWidth := t.pwindow.Width()
-	lineNo := -t.previewer.offset
-	height := t.pwindow.Height()
 	if unchanged {
-		t.pwindow.MoveAndClear(0, 0)
+		t.pwindow.MoveAndClear(0, 0) // Clear scroll offset display
 	} else {
 		t.previewed.filled = false
 		t.pwindow.Erase()
 	}
+
+	height := t.pwindow.Height()
+	header := []string{}
+	body := t.previewer.lines
+	headerLines := t.previewOpts.headerLines
+	// Do not enable preview header lines if it's value is too large
+	if headerLines > 0 && headerLines < util.Min(len(body), height) {
+		header = t.previewer.lines[0:headerLines]
+		body = t.previewer.lines[headerLines:]
+		// Always redraw header
+		t.renderPreviewText(height, header, 0, false)
+		t.pwindow.MoveAndClear(t.pwindow.Y(), 0)
+	}
+	t.renderPreviewText(height, body, -t.previewer.offset+headerLines, unchanged)
+
+	if !unchanged {
+		t.pwindow.FinishFill()
+	}
+}
+
+func (t *Terminal) renderPreviewText(height int, lines []string, lineNo int, unchanged bool) {
+	maxWidth := t.pwindow.Width()
 	var ansi *ansiState
-	for _, line := range t.previewer.lines {
+	for _, line := range lines {
 		var lbg tui.Color = -1
 		if ansi != nil {
 			ansi.lbg = -1
@@ -1314,8 +1341,9 @@ func (t *Terminal) renderPreviewText(unchanged bool) {
 			prefixWidth := 0
 			_, _, ansi = extractColor(line, ansi, func(str string, ansi *ansiState) bool {
 				trimmed := []rune(str)
+				trimmedLen := 0
 				if !t.previewOpts.wrap {
-					trimmed, _ = t.trimRight(trimmed, maxWidth-t.pwindow.X())
+					trimmed, trimmedLen = t.trimRight(trimmed, maxWidth-t.pwindow.X())
 				}
 				str, width := t.processTabs(trimmed, prefixWidth)
 				prefixWidth += width
@@ -1325,7 +1353,8 @@ func (t *Terminal) renderPreviewText(unchanged bool) {
 				} else {
 					fillRet = t.pwindow.CFill(tui.ColPreview.Fg(), tui.ColPreview.Bg(), tui.AttrRegular, str)
 				}
-				return fillRet == tui.FillContinue
+				return trimmedLen == 0 &&
+					(fillRet == tui.FillContinue || t.previewOpts.wrap && fillRet == tui.FillNextLine)
 			})
 			t.previewer.scrollable = t.previewer.scrollable || t.pwindow.Y() == height-1 && t.pwindow.X() == t.pwindow.Width()
 			if fillRet == tui.FillNextLine {
@@ -1346,9 +1375,6 @@ func (t *Terminal) renderPreviewText(unchanged bool) {
 		}
 		lineNo++
 	}
-	if !unchanged {
-		t.pwindow.FinishFill()
-	}
 }
 
 func (t *Terminal) printPreview() {
@@ -1361,7 +1387,7 @@ func (t *Terminal) printPreview() {
 		t.previewer.version == t.previewed.version &&
 		t.previewer.offset == t.previewed.offset
 	t.previewer.scrollable = t.previewer.offset > 0 || numLines > height
-	t.renderPreviewText(unchanged)
+	t.renderPreviewArea(unchanged)
 	t.renderPreviewSpinner()
 	t.previewed.numLines = numLines
 	t.previewed.version = t.previewer.version
@@ -1374,7 +1400,7 @@ func (t *Terminal) printPreviewDelayed() {
 	}
 
 	t.previewer.scrollable = false
-	t.renderPreviewText(true)
+	t.renderPreviewArea(true)
 
 	message := t.trimMessage("Loading ..", t.pwindow.Width())
 	pos := t.pwindow.Width() - len(message)
@@ -1567,43 +1593,33 @@ func (t *Terminal) replacePlaceholder(template string, forcePlus bool, input str
 		template, t.ansi, t.delimiter, t.printsep, forcePlus, input, list)
 }
 
-// Ascii to positive integer
+func (t *Terminal) evaluateScrollOffset(list []*Item, height int) int {
-func atopi(s string) int {
+	offsetExpr := offsetTrimCharsRegex.ReplaceAllString(
-	matches := numericPrefix.FindStringSubmatch(s)
+		t.replacePlaceholder(t.previewOpts.scroll, false, "", list), "")
-	if len(matches) < 2 {
+
-		return 0
+	atoi := func(s string) int {
-	}
+		n, e := strconv.Atoi(s)
-	n, e := strconv.Atoi(matches[1])
+		if e != nil {
-	if e != nil || n < 1 {
 			return 0
 		}
 		return n
 	}
 
-func (t *Terminal) evaluateScrollOffset(list []*Item, height int) int {
+	base := -1
-	offsetExpr := t.replacePlaceholder(t.previewOpts.scroll, false, "", list)
+	for _, component := range offsetComponentRegex.FindAllString(offsetExpr, -1) {
-	nums := strings.Split(offsetExpr, "-")
+		if strings.HasPrefix(component, "-/") {
-	switch len(nums) {
+			component = component[1:]
-	case 0:
-		return 0
-	case 1, 2:
-		base := atopi(nums[0])
-		if base == 0 {
-			return 0
-		} else if len(nums) == 1 {
-			return base - 1
 		}
-		if nums[1][0] == '/' {
+		if component[0] == '/' {
-			denom := atopi(nums[1][1:])
+			denom := atoi(component[1:])
 			if denom == 0 {
 				return base
 			}
 			return base - height/denom
 		}
-		return base - atopi(nums[1]) - 1
+		base += atoi(component)
-	default:
-		return 0
 	}
+	return base
 }
 
 func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, printsep string, forcePlus bool, query string, allItems []*Item) string {
@@ -1711,13 +1727,17 @@ func (t *Terminal) executeCommand(template string, forcePlus bool, background bo
 		cmd.Stdout = os.Stdout
 		cmd.Stderr = os.Stderr
 		t.tui.Pause(true)
+		t.executing.Set(true)
 		cmd.Run()
+		t.executing.Set(false)
 		t.tui.Resume(true, false)
 		t.redraw()
 		t.refresh()
 	} else {
 		t.tui.Pause(false)
+		t.executing.Set(true)
 		cmd.Run()
+		t.executing.Set(false)
 		t.tui.Resume(false, false)
 	}
 	cleanTemporaryFiles()
@@ -1785,11 +1805,26 @@ func (t *Terminal) selectItem(item *Item) bool {
 	return true
 }
 
+func (t *Terminal) selectItemChanged(item *Item) bool {
+	if _, found := t.selected[item.Index()]; found {
+		return false
+	}
+	return t.selectItem(item)
+}
+
 func (t *Terminal) deselectItem(item *Item) {
 	delete(t.selected, item.Index())
 	t.version++
 }
 
+func (t *Terminal) deselectItemChanged(item *Item) bool {
+	if _, found := t.selected[item.Index()]; found {
+		t.deselectItem(item)
+		return true
+	}
+	return false
+}
+
 func (t *Terminal) toggleItem(item *Item) bool {
 	if _, found := t.selected[item.Index()]; !found {
 		return t.selectItem(item)
@@ -1803,7 +1838,7 @@ func (t *Terminal) killPreview(code int) {
 	case t.killChan <- code:
 	default:
 		if code != exitCancel {
-			os.Exit(code)
+			t.eventBox.Set(EvtQuit, code)
 		}
 	}
 }
@@ -1820,8 +1855,12 @@ func (t *Terminal) Loop() {
 		intChan := make(chan os.Signal, 1)
 		signal.Notify(intChan, os.Interrupt, syscall.SIGTERM)
 		go func() {
-			<-intChan
+			for s := range intChan {
+				// Don't quit by SIGINT while executing because it should be for the executing command and not for fzf itself
+				if !(s == os.Interrupt && t.executing.Get()) {
 					t.reqBox.Set(reqQuit, nil)
+				}
+			}
 		}()
 
 		contChan := make(chan os.Signal, 1)
@@ -1898,7 +1937,7 @@ func (t *Terminal) Loop() {
 					cmd := util.ExecCommand(command, true)
 					if pwindow != nil {
 						height := pwindow.Height()
-						initialOffset = util.Max(0, t.evaluateScrollOffset(items, height))
+						initialOffset = util.Max(0, t.evaluateScrollOffset(items, util.Max(0, height-t.previewOpts.headerLines)))
 						env := os.Environ()
 						lines := fmt.Sprintf("LINES=%d", height)
 						columns := fmt.Sprintf("COLUMNS=%d", pwindow.Width())
@@ -1983,7 +2022,7 @@ func (t *Terminal) Loop() {
 								case code := <-t.killChan:
 									if code != exitCancel {
 										util.KillCommand(cmd)
-										os.Exit(code)
+										t.eventBox.Set(EvtQuit, code)
 									} else {
 										timer := time.NewTimer(previewCancelWait)
 										select {
@@ -2020,16 +2059,6 @@ func (t *Terminal) Loop() {
 		}()
 	}
 
-	exit := func(getCode func() int) {
-		t.tui.Close()
-		code := getCode()
-		if code <= exitNoMatch && t.history != nil {
-			t.history.append(string(t.input))
-		}
-		// prof.Stop()
-		t.killPreview(code)
-	}
-
 	refreshPreview := func(command string) {
 		if len(command) > 0 && t.isPreviewEnabled() {
 			_, list := t.buildPlusList(command, false)
@@ -2041,7 +2070,19 @@ func (t *Terminal) Loop() {
 	go func() {
 		var focusedIndex int32 = minItem.Index()
 		var version int64 = -1
-		for {
+		running := true
+		code := exitError
+		exit := func(getCode func() int) {
+			t.tui.Close()
+			code = getCode()
+			if code <= exitNoMatch && t.history != nil {
+				t.history.append(string(t.input))
+			}
+			running = false
+			t.mutex.Unlock()
+		}
+
+		for running {
 			t.reqBox.Wait(func(events *util.Events) {
 				defer events.Clear()
 				t.mutex.Lock()
@@ -2087,6 +2128,7 @@ func (t *Terminal) Loop() {
 							}
 							return exitNoMatch
 						})
+						return
 					case reqPreviewDisplay:
 						result := value.(previewResult)
 						if t.previewer.version != result.version {
@@ -2098,7 +2140,7 @@ func (t *Terminal) Loop() {
 						if t.previewer.following {
 							t.previewer.offset = len(t.previewer.lines) - t.pwindow.Height()
 						} else if result.offset >= 0 {
-							t.previewer.offset = util.Constrain(result.offset, 0, len(t.previewer.lines)-1)
+							t.previewer.offset = util.Constrain(result.offset, t.previewOpts.headerLines, len(t.previewer.lines)-1)
 						}
 						t.printPreview()
 					case reqPreviewRefresh:
@@ -2111,14 +2153,18 @@ func (t *Terminal) Loop() {
 							t.printer(string(t.input))
 							return exitOk
 						})
+						return
 					case reqQuit:
 						exit(func() int { return exitInterrupt })
+						return
 					}
 				}
 				t.refresh()
 				t.mutex.Unlock()
 			})
 		}
+		// prof.Stop()
+		t.killPreview(code)
 	}()
 
 	looping := true
@@ -2167,7 +2213,7 @@ func (t *Terminal) Loop() {
 			if t.previewOpts.cycle {
 				newOffset = (newOffset + numLines) % numLines
 			}
-			newOffset = util.Constrain(newOffset, 0, numLines-1)
+			newOffset = util.Constrain(newOffset, t.previewOpts.headerLines, numLines-1)
 			if t.previewer.offset != newOffset {
 				t.previewer.offset = newOffset
 				req(reqPreviewRefresh)
@@ -2341,6 +2387,16 @@ func (t *Terminal) Loop() {
 				} else {
 					req(reqQuit)
 				}
+			case actSelect:
+				current := t.currentItem()
+				if t.multi > 0 && current != nil && t.selectItemChanged(current) {
+					req(reqList, reqInfo)
+				}
+			case actDeselect:
+				current := t.currentItem()
+				if t.multi > 0 && current != nil && t.deselectItemChanged(current) {
+					req(reqList, reqInfo)
+				}
 			case actToggle:
 				if t.multi > 0 && t.merger.Length() > 0 && toggle() {
 					req(reqList)

src/tui/light.go

@@ -906,12 +906,6 @@ func (w *LightWindow) fill(str string, onMove func()) FillReturn {
 	for i, line := range allLines {
 		lines := wrapLine(line, w.posx, w.width, w.tabstop)
 		for j, wl := range lines {
-			if w.posx >= w.Width()-1 && wl.displayWidth == 0 {
-				if w.posy < w.height-1 {
-					w.Move(w.posy+1, 0)
-				}
-				return FillNextLine
-			}
 			w.stderrInternal(wl.text, false)
 			w.posx += wl.displayWidth
 
@@ -926,6 +920,14 @@ func (w *LightWindow) fill(str string, onMove func()) FillReturn {
 			}
 		}
 	}
+	if w.posx+1 >= w.Width() {
+		if w.posy+1 >= w.height {
+			return FillSuspend
+		}
+		w.Move(w.posy+1, 0)
+		onMove()
+		return FillNextLine
+	}
 	return FillContinue
 }
 

test/test_go.rb

@@ -1890,6 +1890,158 @@ class TestGoFZF < TestBase
     tmux.send_keys 'C-l', 'closed'
     tmux.until { |lines| assert_includes lines[0], 'closed' }
   end
+
+  def test_select_deselect
+    tmux.send_keys "seq 3 | #{FZF} --multi --bind up:deselect+up,down:select+down", :Enter
+    tmux.until { |lines| assert_equal 3, lines.match_count }
+    tmux.send_keys :Tab
+    tmux.until { |lines| assert_equal 1, lines.select_count }
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_equal 0, lines.select_count }
+    tmux.send_keys :Down, :Down
+    tmux.until { |lines| assert_equal 2, lines.select_count }
+    tmux.send_keys :Tab
+    tmux.until { |lines| assert_equal 1, lines.select_count }
+    tmux.send_keys :Down, :Down
+    tmux.until { |lines| assert_equal 2, lines.select_count }
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_equal 1, lines.select_count }
+    tmux.send_keys :Down
+    tmux.until { |lines| assert_equal 1, lines.select_count }
+    tmux.send_keys :Down
+    tmux.until { |lines| assert_equal 2, lines.select_count }
+  end
+
+  def test_interrupt_execute
+    tmux.send_keys "seq 100 | #{FZF} --bind 'ctrl-l:execute:echo executing {}; sleep 100'", :Enter
+    tmux.until { |lines| assert_equal 100, lines.item_count }
+    tmux.send_keys 'C-l'
+    tmux.until { |lines| assert lines.any_include?('executing 1') }
+    tmux.send_keys 'C-c'
+    tmux.until { |lines| assert_equal 100, lines.item_count }
+    tmux.send_keys 99
+    tmux.until { |lines| assert_equal 1, lines.match_count }
+  end
+
+  def test_kill_default_command_on_abort
+    script = tempname + '.sh'
+    writelines(script,
+               ['#!/usr/bin/env bash',
+                "echo 'Started'",
+                'while :; do sleep 1; done'])
+    system("chmod +x #{script}")
+
+    tmux.send_keys fzf.sub('FZF_DEFAULT_COMMAND=', "FZF_DEFAULT_COMMAND=#{script}"), :Enter
+    tmux.until { |lines| assert_equal 1, lines.item_count }
+    tmux.send_keys 'C-c'
+    tmux.send_keys 'C-l', 'closed'
+    tmux.until { |lines| assert_includes lines[0], 'closed' }
+    wait { refute system("pgrep -f #{script}") }
+  ensure
+    system("pkill -9 -f #{script}")
+    begin
+      File.unlink(script)
+    rescue StandardError
+      nil
+    end
+  end
+
+  def test_kill_default_command_on_accept
+    script = tempname + '.sh'
+    writelines(script,
+               ['#!/usr/bin/env bash',
+                "echo 'Started'",
+                'while :; do sleep 1; done'])
+    system("chmod +x #{script}")
+
+    tmux.send_keys fzf.sub('FZF_DEFAULT_COMMAND=', "FZF_DEFAULT_COMMAND=#{script}"), :Enter
+    tmux.until { |lines| assert_equal 1, lines.item_count }
+    tmux.send_keys :Enter
+    assert_equal 'Started', readonce.chomp
+    wait { refute system("pgrep -f #{script}") }
+  ensure
+    system("pkill -9 -f #{script}")
+    begin
+      File.unlink(script)
+    rescue StandardError
+      nil
+    end
+  end
+
+  def test_kill_reload_command_on_abort
+    script = tempname + '.sh'
+    writelines(script,
+               ['#!/usr/bin/env bash',
+                "echo 'Started'",
+                'while :; do sleep 1; done'])
+    system("chmod +x #{script}")
+
+    tmux.send_keys "seq 1 3 | #{fzf("--bind 'ctrl-r:reload(#{script})'")}", :Enter
+    tmux.until { |lines| assert_equal 3, lines.item_count }
+    tmux.send_keys 'C-r'
+    tmux.until { |lines| assert_equal 1, lines.item_count }
+    tmux.send_keys 'C-c'
+    tmux.send_keys 'C-l', 'closed'
+    tmux.until { |lines| assert_includes lines[0], 'closed' }
+    wait { refute system("pgrep -f #{script}") }
+  ensure
+    system("pkill -9 -f #{script}")
+    begin
+      File.unlink(script)
+    rescue StandardError
+      nil
+    end
+  end
+
+  def test_kill_reload_command_on_accept
+    script = tempname + '.sh'
+    writelines(script,
+               ['#!/usr/bin/env bash',
+                "echo 'Started'",
+                'while :; do sleep 1; done'])
+    system("chmod +x #{script}")
+
+    tmux.send_keys "seq 1 3 | #{fzf("--bind 'ctrl-r:reload(#{script})'")}", :Enter
+    tmux.until { |lines| assert_equal 3, lines.item_count }
+    tmux.send_keys 'C-r'
+    tmux.until { |lines| assert_equal 1, lines.item_count }
+    tmux.send_keys :Enter
+    assert_equal 'Started', readonce.chomp
+    wait { refute system("pgrep -f #{script}") }
+  ensure
+    system("pkill -9 -f #{script}")
+    begin
+      File.unlink(script)
+    rescue StandardError
+      nil
+    end
+  end
+
+  def test_preview_header
+    tmux.send_keys "seq 100 | #{FZF} --bind ctrl-k:preview-up+preview-up,ctrl-j:preview-down+preview-down+preview-down --preview 'seq 1000' --preview-window 'top:+{1}:~3'", :Enter
+    tmux.until { |lines| assert_equal 100, lines.item_count }
+    top5 = ->(lines) { lines.drop(1).take(5).map { |s| s[/[0-9]+/] } }
+    tmux.until do |lines|
+      assert_includes lines[1], '4/1000'
+      assert_equal(%w[1 2 3 4 5], top5[lines])
+    end
+    tmux.send_keys '55'
+    tmux.until do |lines|
+      assert_equal 1, lines.match_count
+      assert_equal(%w[1 2 3 55 56], top5[lines])
+    end
+    tmux.send_keys 'C-J'
+    tmux.until do |lines|
+      assert_equal(%w[1 2 3 58 59], top5[lines])
+    end
+    tmux.send_keys :BSpace
+    tmux.until do |lines|
+      assert_equal 19, lines.match_count
+      assert_equal(%w[1 2 3 5 6], top5[lines])
+    end
+    tmux.send_keys 'C-K'
+    tmux.until { |lines| assert_equal(%w[1 2 3 4 5], top5[lines]) }
+  end
 end
 
 module TestShell
@@ -2060,7 +2212,7 @@ module CompletionTest
     end
 
     # ~USERNAME**<TAB>
-    user = ENV['USER']
+    user = `whoami`.chomp
     tmux.send_keys 'C-u'
     tmux.send_keys "cat ~#{user}**", :Tab
     tmux.until { |lines| assert_operator lines.match_count, :>, 0 }