0.29.0

Fix #2692

ADVANCED.md

@@ -429,30 +429,34 @@ Admittedly, that was a silly example. Here's a practical one for browsing
 Kubernetes pods.
 
 ```bash
-#!/usr/bin/env bash
+pods() {
-
+  FZF_DEFAULT_COMMAND="kubectl get pods --all-namespaces" \
-read -ra tokens < <(
+    fzf --info=inline --layout=reverse --header-lines=1 \
-  kubectl get pods --all-namespaces |
-    fzf --info=inline --layout=reverse --header-lines=1 --border \
         --prompt "$(kubectl config current-context | sed 's/-context$//')> " \
-        --header $'Press CTRL-O to open log in editor\n\n' \
+        --header $'╱ Enter (kubectl exec) ╱ CTRL-O (open log in editor) ╱ CTRL-R (reload) ╱\n\n' \
-        --bind ctrl-/:toggle-preview \
+        --bind 'ctrl-/:change-preview-window(80%,border-bottom|hidden|)' \
-        --bind 'ctrl-o:execute:${EDITOR:-vim} <(kubectl logs --namespace {1} {2}) > /dev/tty' \
+        --bind 'enter:execute:kubectl exec -it --namespace {1} {2} -- bash > /dev/tty' \
-        --preview-window up,follow \
+        --bind 'ctrl-o:execute:${EDITOR:-vim} <(kubectl logs --all-containers --namespace {1} {2}) > /dev/tty' \
-        --preview 'kubectl logs --follow --tail=100000 --namespace {1} {2}' "$@"
+        --bind 'ctrl-r:reload:$FZF_DEFAULT_COMMAND' \
-)
+        --preview-window up:follow \
-[ ${#tokens} -gt 1 ] &&
+        --preview 'kubectl logs --follow --all-containers --tail=10000 --namespace {1} {2}' "$@"
-  kubectl exec -it --namespace "${tokens[0]}" "${tokens[1]}" -- bash
+}
 ```
 
 ![image](https://user-images.githubusercontent.com/700826/113473547-1d7a4880-94a5-11eb-98ef-9aa6f0ed215a.png)
 
 - The preview window will *"log tail"* the pod
     - Holding on to a large amount of log will consume a lot of memory. So we
-      limited the initial log amount with `--tail=100000`.
+      limited the initial log amount with `--tail=10000`.
-- With `execute` binding, you can press CTRL-O to open the log in your editor
+- `execute` bindings allow you to run any command without leaving fzf
-  without leaving fzf
+    - Press enter key on a pod to `kubectl exec` into it
-- Select a pod (with an enter key) to `kubectl exec` into it
+    - Press CTRL-O to open the log in your editor
+- Press CTRL-R to reload the pod list
+- Press CTRL-/ repeatedly to to rotate through a different sets of preview
+  window options
+    1. `80%,border-bottom`
+    1. `hidden`
+    1. Empty string after `|` translates to the default options from `--preview-window`
 
 Key bindings for git objects
 ----------------------------

CHANGELOG.md

@@ -1,6 +1,37 @@
 CHANGELOG
 =========
 
+0.29.0
+------
+- Added `change-preview(...)` action to change the `--preview` command
+    - cf. `preview(...)` is a one-off action that doesn't change the default
+      preview command
+- Added `change-preview-window(...)` action
+    - You can rotate through the different options separated by `|`
+      ```sh
+      fzf --preview 'cat {}' --preview-window right:40% \
+          --bind 'ctrl-/:change-preview-window(right,70%|down,40%,border-top|hidden|)'
+      ```
+- Fixed rendering of the prompt line when overflow occurs with `--info=inline`
+
+0.28.0
+------
+- Added `--header-first` option to print header before the prompt line
+  ```sh
+  fzf --header $'Welcome to fzf\n▔▔▔▔▔▔▔▔▔▔▔▔▔▔' --reverse --height 30% --border --header-first
+  ```
+- Added `--scroll-off=LINES` option (similar to `scrolloff` option of Vim)
+    - You can set it to a very large number so that the cursor stays in the
+      middle of the screen while scrolling
+      ```sh
+      fzf --scroll-off=5
+      fzf --scroll-off=999
+      ```
+- Fixed bug where preview window is not updated on `reload` (#2644)
+- fzf on Windows will also use `$SHELL` to execute external programs
+    - See #2638 and #2647
+    - Thanks to @rashil2000, @vovcacik, and @janlazo
+
 0.27.3
 ------
 - Preview window is `hidden` by default when there are `preview` bindings but

Dockerfile

@@ -1,4 +1,4 @@
-FROM archlinux/base:latest
+FROM archlinux
 RUN pacman -Sy && pacman --noconfirm -S awk git tmux zsh fish ruby procps go make gcc
 RUN gem install --no-document -v 5.14.2 minitest
 RUN echo '. /usr/share/bash-completion/completions/git' >> ~/.bashrc

Makefile

@@ -102,6 +102,7 @@ endif
 	grep -qF $(VERSION) install.ps1
 
 	# Make release note out of CHANGELOG.md
+	mkdir -p tmp
 	sed -n '/^$(VERSION_REGEX)$$/,/^[0-9]/p' CHANGELOG.md | tail -r | \
 		sed '1,/^ *$$/d' | tail -r | sed 1,2d | tee tmp/release-note
 

README.md

@@ -86,7 +86,7 @@ stuff.
 
 ### Using Homebrew
 
-You can use [Homebrew](http://brew.sh/) (on macOS or Linux)
+You can use [Homebrew](https://brew.sh/) (on macOS or Linux)
 to install fzf.
 
 ```sh
@@ -131,6 +131,8 @@ git clone --depth 1 https://github.com/junegunn/fzf.git ~/.fzf
 >
 > Refer to the package documentation for more information. (e.g. `apt-cache show fzf`)
 
+[![Packaging status](https://repology.org/badge/vertical-allrepos/fzf.svg)](https://repology.org/project/fzf/versions)
+
 ### Windows
 
 Pre-built binaries for Windows can be downloaded [here][bin]. fzf is also

install

@@ -2,7 +2,7 @@
 
 set -u
 
-version=0.27.3
+version=0.29.0
 auto_completion=
 key_bindings=
 update_config=2

install.ps1

@@ -1,4 +1,4 @@
-$version="0.27.3"
+$version="0.29.0"
 
 $fzf_base=Split-Path -Parent $MyInvocation.MyCommand.Definition
 

main.go

@@ -1,11 +1,11 @@
 package main
 
 import (
-	"github.com/junegunn/fzf/src"
+	fzf "github.com/junegunn/fzf/src"
 	"github.com/junegunn/fzf/src/protector"
 )
 
-var version string = "0.27"
+var version string = "0.29"
 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 "Oct 2021" "fzf 0.27.3" "fzf-tmux - open fzf in tmux split pane"
+.TH fzf-tmux 1 "Dec 2021" "fzf 0.29.0" "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 "Oct 2021" "fzf 0.27.3" "fzf - a command-line fuzzy finder"
+.TH fzf 1 "Dec 2021" "fzf 0.29.0" "fzf - a command-line fuzzy finder"
 
 .SH NAME
 fzf - a command-line fuzzy finder
@@ -135,10 +135,14 @@ Enable cyclic scroll
 Keep the right end of the line visible when it's too long. Effective only when
 the query string is empty.
 .TP
+.BI "--scroll-off=" "LINES"
+Number of screen lines to keep above or below when scrolling to the top or to
+the bottom (default: 0).
+.TP
 .B "--no-hscroll"
 Disable horizontal scroll
 .TP
-.BI "--hscroll-off=" "COL"
+.BI "--hscroll-off=" "COLS"
 Number of screen columns to keep to the right of the highlighted substring
 (default: 10). Setting it to a large value will cause the text to be positioned
 on the center of the screen.
@@ -295,6 +299,9 @@ are not affected by \fB--with-nth\fR. ANSI color codes are processed even when
 The first N lines of the input are treated as the sticky header. When
 \fB--with-nth\fR is set, the lines are transformed just like the other
 lines that follow.
+.TP
+.B "--header-first"
+Print header before the prompt line
 .SS Display
 .TP
 .B "--ansi"
@@ -813,6 +820,8 @@ A key or an event can be bound to one or more of the following actions.
     \fBbackward-word\fR              \fIalt-b   shift-left\fR
     \fBbeginning-of-line\fR          \fIctrl-a  home\fR
     \fBcancel\fR                     (clear query string if not empty, abort fzf otherwise)
+    \fBchange-preview(...)\fR        (change \fB--preview\fR option)
+    \fBchange-preview-window(...)\fR (change \fB--preview-window\fR option; rotate through the multiple option sets separated by '|')
     \fBchange-prompt(...)\fR         (change prompt to the given string)
     \fBclear-screen\fR               \fIctrl-l\fR
     \fBclear-selection\fR            (clear multi-selection)
@@ -853,6 +862,7 @@ A key or an event can be bound to one or more of the following actions.
     \fBpreview-top\fR
     \fBprevious-history\fR           (\fIctrl-p\fR on \fB--history\fR)
     \fBprint-query\fR                (print query and exit)
+    \fBput\fR                        (put the character to the prompt)
     \fBrefresh-preview\fR
     \fBreload(...)\fR                (see below for the details)
     \fBreplace-query\fR              (replace query string with the current selection)
@@ -962,7 +972,6 @@ commands in addition to the default preview command given by \fB--preview\fR
 option.
 
 e.g.
-
      # Default preview command with an extra preview binding
      fzf --preview 'file {}' --bind '?:preview:cat {}'
 
@@ -973,6 +982,22 @@ e.g.
      # Preview window hidden by default, it appears when you first hit '?'
      fzf --bind '?:preview:cat {}' --preview-window hidden
 
+.SS CHANGE PREVIEW WINDOW ATTRIBUTES
+
+\fBchange-preview-window\fR action can be used to change the properties of the
+preview window. Unlike the \fB--preview-window\fR option, you can specify
+multiple sets of options separated by '|' characters.
+
+e.g.
+     # Rotate through the options using CTRL-/
+     fzf --preview 'cat {}' --bind 'ctrl-/:change-preview-window(right,70%|down,40%,border-horizontal|hidden|right)'
+
+     # The default properties given by `--preview-window` are inherited, so an empty string in the list is interpreted as the default
+     fzf --preview 'cat {}' --preview-window 'right,40%,border-left' --bind 'ctrl-/:change-preview-window(70%|down,border-top|hidden|)'
+
+     # This is equivalent to toggle-preview action
+     fzf --preview 'cat {}' --bind 'ctrl-/:change-preview-window(hidden|)'
+
 .SH AUTHOR
 Junegunn Choi (\fIjunegunn.c@gmail.com\fR)
 

plugin/fzf.vim

@@ -444,6 +444,12 @@ function! s:use_sh()
   return [shell, shellslash, shellcmdflag, shellxquote]
 endfunction
 
+function! s:writefile(...)
+  if call('writefile', a:000) == -1
+    throw 'Failed to write temporary file. Check if you can write to the path tempname() returns.'
+  endif
+endfunction
+
 function! fzf#run(...) abort
 try
   let [shell, shellslash, shellcmdflag, shellxquote] = s:use_sh()
@@ -471,7 +477,7 @@ try
       let source_command = source
     elseif type == 3
       let temps.input = s:fzf_tempname()
-      call writefile(source, temps.input)
+      call s:writefile(source, temps.input)
       let source_command = (s:is_win ? 'type ' : 'cat ').fzf#shellescape(temps.input)
     else
       throw 'Invalid source type'
@@ -515,7 +521,7 @@ try
   call s:callback(dict, lines)
   return lines
 finally
-  if len(source_command)
+  if exists('source_command') && len(source_command)
     if len(prev_default_command)
       let $FZF_DEFAULT_COMMAND = prev_default_command
     else
@@ -660,7 +666,7 @@ function! s:execute(dict, command, use_height, temps) abort
   endif
   if s:is_win
     let batchfile = s:fzf_tempname().'.bat'
-    call writefile(s:wrap_cmds(command), batchfile)
+    call s:writefile(s:wrap_cmds(command), batchfile)
     let command = batchfile
     let a:temps.batchfile = batchfile
     if has('nvim')
@@ -678,7 +684,7 @@ function! s:execute(dict, command, use_height, temps) abort
     endif
   elseif has('win32unix') && $TERM !=# 'cygwin'
     let shellscript = s:fzf_tempname()
-    call writefile([command], shellscript)
+    call s:writefile([command], shellscript)
     let command = 'cmd.exe /C '.fzf#shellescape('set "TERM=" & start /WAIT sh -c '.shellscript)
     let a:temps.shellscript = shellscript
   endif
@@ -877,7 +883,7 @@ function! s:execute_term(dict, command, temps) abort
     call s:pushd(a:dict)
     if s:is_win
       let fzf.temps.batchfile = s:fzf_tempname().'.bat'
-      call writefile(s:wrap_cmds(a:command), fzf.temps.batchfile)
+      call s:writefile(s:wrap_cmds(a:command), fzf.temps.batchfile)
       let command = fzf.temps.batchfile
     else
       let command = a:command

shell/completion.bash

@@ -32,7 +32,7 @@ fi
 ###########################################################
 
 # To redraw line after fzf closes (printf '\e[5n')
-bind '"\e[0n": redraw-current-line'
+bind '"\e[0n": redraw-current-line' 2> /dev/null
 
 __fzf_comprun() {
   if [[ "$(type -t _fzf_comprun 2>&1)" = function ]]; then

shell/key-bindings.bash

@@ -41,7 +41,7 @@ __fzf_cd__() {
   local cmd dir
   cmd="${FZF_ALT_C_COMMAND:-"command find -L . -mindepth 1 \\( -path '*/\\.*' -o -fstype 'sysfs' -o -fstype 'devfs' -o -fstype 'devtmpfs' -o -fstype 'proc' \\) -prune \
     -o -type d -print 2> /dev/null | cut -b3-"}"
-  dir=$(eval "$cmd" | FZF_DEFAULT_OPTS="--height ${FZF_TMUX_HEIGHT:-40%} --reverse --bind=ctrl-z:ignore $FZF_DEFAULT_OPTS $FZF_ALT_C_OPTS" $(__fzfcmd) +m) && printf 'cd %q' "$dir"
+  dir=$(eval "$cmd" | FZF_DEFAULT_OPTS="--height ${FZF_TMUX_HEIGHT:-40%} --reverse --bind=ctrl-z:ignore $FZF_DEFAULT_OPTS $FZF_ALT_C_OPTS" $(__fzfcmd) +m) && printf 'cd -- %q' "$dir"
 }
 
 __fzf_history__() {

shell/key-bindings.fish

@@ -87,7 +87,7 @@ function fzf_key_bindings
       eval "$FZF_ALT_C_COMMAND | "(__fzfcmd)' +m --query "'$fzf_query'"' | read -l result
 
       if [ -n "$result" ]
-        cd $result
+        cd -- $result
 
         # Remove last token from commandline.
         commandline -t ""

shell/key-bindings.zsh

@@ -79,7 +79,7 @@ fzf-cd-widget() {
     return 0
   fi
   zle push-line # Clear buffer. Auto-restored on next prompt.
-  BUFFER="cd ${(q)dir}"
+  BUFFER="cd -- ${(q)dir}"
   zle accept-line
   local ret=$?
   unset dir # ensure this doesn't end up appearing in prompt expansion

src/options.go

@@ -44,8 +44,10 @@ const usage = `usage: fzf [options]
     --bind=KEYBINDS       Custom key bindings. Refer to the man page.
     --cycle               Enable cyclic scroll
     --keep-right          Keep the right end of the line visible on overflow
+    --scroll-off=LINES    Number of screen lines to keep above or below when
+                          scrolling to the top or to the bottom (default: 0)
     --no-hscroll          Disable horizontal scroll
-    --hscroll-off=COL     Number of screen columns to keep to the right of the
+    --hscroll-off=COLS    Number of screen columns to keep to the right of the
                           highlighted substring (default: 10)
     --filepath-word       Make word-wise movements respect path separators
     --jump-labels=CHARS   Label characters for jump and jump-accept
@@ -67,6 +69,7 @@ const usage = `usage: fzf [options]
     --marker=STR          Multi-select marker (default: '>')
     --header=STR          String to print as header
     --header-lines=N      The first N lines of the input are treated as header
+    --header-first        Print header before the prompt line
 
   Display
     --ansi                Enable processing of ANSI color codes
@@ -173,6 +176,14 @@ type previewOpts struct {
 	headerLines int
 }
 
+func (a previewOpts) sameLayout(b previewOpts) bool {
+	return a.size == b.size && a.position == b.position && a.border == b.border && a.hidden == b.hidden
+}
+
+func (a previewOpts) sameContentLayout(b previewOpts) bool {
+	return a.wrap == b.wrap && a.headerLines == b.headerLines
+}
+
 // Options stores the values of command-line options
 type Options struct {
 	Fuzzy       bool
@@ -200,6 +211,7 @@ type Options struct {
 	KeepRight   bool
 	Hscroll     bool
 	HscrollOff  int
+	ScrollOff   int
 	FileWord    bool
 	InfoStyle   infoStyle
 	JumpLabels  string
@@ -212,7 +224,7 @@ type Options struct {
 	Filter      *string
 	ToggleSort  bool
 	Expect      map[tui.Event]string
-	Keymap      map[tui.Event][]action
+	Keymap      map[tui.Event][]*action
 	Preview     previewOpts
 	PrintQuery  bool
 	ReadZero    bool
@@ -222,6 +234,7 @@ type Options struct {
 	History     *History
 	Header      []string
 	HeaderLines int
+	HeaderFirst bool
 	Margin      [4]sizeSpec
 	Padding     [4]sizeSpec
 	BorderShape tui.BorderShape
@@ -261,6 +274,7 @@ func defaultOptions() *Options {
 		KeepRight:   false,
 		Hscroll:     true,
 		HscrollOff:  10,
+		ScrollOff:   0,
 		FileWord:    false,
 		InfoStyle:   infoDefault,
 		JumpLabels:  defaultJumpLabels,
@@ -273,7 +287,7 @@ func defaultOptions() *Options {
 		Filter:      nil,
 		ToggleSort:  false,
 		Expect:      make(map[tui.Event]string),
-		Keymap:      make(map[tui.Event][]action),
+		Keymap:      make(map[tui.Event][]*action),
 		Preview:     defaultPreviewOpts(""),
 		PrintQuery:  false,
 		ReadZero:    false,
@@ -283,6 +297,7 @@ func defaultOptions() *Options {
 		History:     nil,
 		Header:      make([]string, 0),
 		HeaderLines: 0,
+		HeaderFirst: false,
 		Margin:      defaultMargin(),
 		Padding:     defaultMargin(),
 		Unicode:     true,
@@ -780,10 +795,10 @@ func init() {
 	// Backreferences are not supported.
 	// "~!@#$%^&*;/|".each_char.map { |c| Regexp.escape(c) }.map { |c| "#{c}[^#{c}]*#{c}" }.join('|')
 	executeRegexp = regexp.MustCompile(
-		`(?si)[:+](execute(?:-multi|-silent)?|reload|preview|change-prompt|unbind):.+|[:+](execute(?:-multi|-silent)?|reload|preview|change-prompt|unbind)(\([^)]*\)|\[[^\]]*\]|~[^~]*~|![^!]*!|@[^@]*@|\#[^\#]*\#|\$[^\$]*\$|%[^%]*%|\^[^\^]*\^|&[^&]*&|\*[^\*]*\*|;[^;]*;|/[^/]*/|\|[^\|]*\|)`)
+		`(?si)[:+](execute(?:-multi|-silent)?|reload|preview|change-prompt|change-preview-window|change-preview|unbind):.+|[:+](execute(?:-multi|-silent)?|reload|preview|change-prompt|change-preview-window|change-preview|unbind)(\([^)]*\)|\[[^\]]*\]|~[^~]*~|![^!]*!|@[^@]*@|\#[^\#]*\#|\$[^\$]*\$|%[^%]*%|\^[^\^]*\^|&[^&]*&|\*[^\*]*\*|;[^;]*;|/[^/]*/|\|[^\|]*\|)`)
 }
 
-func parseKeymap(keymap map[tui.Event][]action, str string) {
+func parseKeymap(keymap map[tui.Event][]*action, str string) {
 	masked := executeRegexp.ReplaceAllStringFunc(str, func(src string) string {
 		symbol := ":"
 		if strings.HasPrefix(src, "+") {
@@ -792,6 +807,10 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 		prefix := symbol + "execute"
 		if strings.HasPrefix(src[1:], "reload") {
 			prefix = symbol + "reload"
+		} else if strings.HasPrefix(src[1:], "change-preview-window") {
+			prefix = symbol + "change-preview-window"
+		} else if strings.HasPrefix(src[1:], "change-preview") {
+			prefix = symbol + "change-preview"
 		} else if strings.HasPrefix(src[1:], "preview") {
 			prefix = symbol + "preview"
 		} else if strings.HasPrefix(src[1:], "unbind") {
@@ -835,7 +854,7 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 
 		idx2 := len(pair[0]) + 1
 		specs := strings.Split(pair[1], "+")
-		actions := make([]action, 0, len(specs))
+		actions := make([]*action, 0, len(specs))
 		appendAction := func(types ...actionType) {
 			actions = append(actions, toActions(types...)...)
 		}
@@ -974,6 +993,12 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 				appendAction(actEnableSearch)
 			case "disable-search":
 				appendAction(actDisableSearch)
+			case "put":
+				if key.Type == tui.Rune && unicode.IsGraphic(key.Char) {
+					appendAction(actRune)
+				} else {
+					errorExit("unable to put non-printable character: " + pair[0])
+				}
 			default:
 				t := isExecuteAction(specLower)
 				if t == actIgnore {
@@ -989,6 +1014,10 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 						offset = len("reload")
 					case actPreview:
 						offset = len("preview")
+					case actChangePreviewWindow:
+						offset = len("change-preview-window")
+					case actChangePreview:
+						offset = len("change-preview")
 					case actChangePrompt:
 						offset = len("change-prompt")
 					case actUnbind:
@@ -1004,17 +1033,22 @@ func parseKeymap(keymap map[tui.Event][]action, str string) {
 					if spec[offset] == ':' {
 						if specIndex == len(specs)-1 {
 							actionArg = spec[offset+1:]
-							actions = append(actions, action{t: t, a: actionArg})
+							actions = append(actions, &action{t: t, a: actionArg})
 						} else {
 							prevSpec = spec + "+"
 							continue
 						}
 					} else {
 						actionArg = spec[offset+1 : len(spec)-1]
-						actions = append(actions, action{t: t, a: actionArg})
+						actions = append(actions, &action{t: t, a: actionArg})
 					}
 					if t == actUnbind {
 						parseKeyChords(actionArg, "unbind target required")
+					} else if t == actChangePreviewWindow {
+						opts := previewOpts{}
+						for _, arg := range strings.Split(actionArg, "|") {
+							parsePreviewWindow(&opts, arg)
+						}
 					}
 				}
 			}
@@ -1040,6 +1074,10 @@ func isExecuteAction(str string) actionType {
 		return actUnbind
 	case "preview":
 		return actPreview
+	case "change-preview-window":
+		return actChangePreviewWindow
+	case "change-preview":
+		return actChangePreview
 	case "change-prompt":
 		return actChangePrompt
 	case "execute":
@@ -1052,7 +1090,7 @@ func isExecuteAction(str string) actionType {
 	return actIgnore
 }
 
-func parseToggleSort(keymap map[tui.Event][]action, str string) {
+func parseToggleSort(keymap map[tui.Event][]*action, str string) {
 	keys := parseKeyChords(str, "key name required")
 	if len(keys) != 1 {
 		errorExit("multiple keys specified")
@@ -1354,6 +1392,8 @@ func parseOptions(opts *Options, allArgs []string) {
 			opts.Hscroll = false
 		case "--hscroll-off":
 			opts.HscrollOff = nextInt(allArgs, &i, "hscroll offset required")
+		case "--scroll-off":
+			opts.ScrollOff = nextInt(allArgs, &i, "scroll offset required")
 		case "--filepath-word":
 			opts.FileWord = true
 		case "--no-filepath-word":
@@ -1421,6 +1461,10 @@ func parseOptions(opts *Options, allArgs []string) {
 		case "--header-lines":
 			opts.HeaderLines = atoi(
 				nextString(allArgs, &i, "number of header lines required"))
+		case "--header-first":
+			opts.HeaderFirst = true
+		case "--no-header-first":
+			opts.HeaderFirst = false
 		case "--preview":
 			opts.Preview.command = nextString(allArgs, &i, "preview command required")
 		case "--no-preview":
@@ -1530,6 +1574,8 @@ func parseOptions(opts *Options, allArgs []string) {
 				opts.Tabstop = atoi(value)
 			} else if match, value := optString(arg, "--hscroll-off="); match {
 				opts.HscrollOff = atoi(value)
+			} else if match, value := optString(arg, "--scroll-off="); match {
+				opts.ScrollOff = atoi(value)
 			} else if match, value := optString(arg, "--jump-labels="); match {
 				opts.JumpLabels = value
 				validateJumpLabels = true
@@ -1547,6 +1593,10 @@ func parseOptions(opts *Options, allArgs []string) {
 		errorExit("hscroll offset must be a non-negative integer")
 	}
 
+	if opts.ScrollOff < 0 {
+		errorExit("scroll offset must be a non-negative integer")
+	}
+
 	if opts.Tabstop < 1 {
 		errorExit("tab stop must be a positive integer")
 	}
@@ -1608,11 +1658,29 @@ func postProcessOptions(opts *Options) {
 	// Extend the default key map
 	keymap := defaultKeymap()
 	for key, actions := range opts.Keymap {
+		var lastChangePreviewWindow *action
 		for _, act := range actions {
-			if act.t == actToggleSort {
+			switch act.t {
+			case actToggleSort:
+				// To display "+S"/"-S" on info line
 				opts.ToggleSort = true
+			case actChangePreviewWindow:
+				lastChangePreviewWindow = act
 			}
 		}
+		// Re-organize actions so that we only keep the last change-preview-window
+		// and it comes first in the list.
+		//  *  change-preview-window(up,+10)+preview(sleep 3; cat {})+change-preview-window(up,+20)
+		//  -> change-preview-window(up,+20)+preview(sleep 3; cat {})
+		if lastChangePreviewWindow != nil {
+			reordered := []*action{lastChangePreviewWindow}
+			for _, act := range actions {
+				if act.t != actChangePreviewWindow {
+					reordered = append(reordered, act)
+				}
+			}
+			actions = reordered
+		}
 		keymap[key] = actions
 	}
 	opts.Keymap = keymap

src/terminal.go

@@ -4,6 +4,7 @@ import (
 	"bufio"
 	"fmt"
 	"io/ioutil"
+	"math"
 	"os"
 	"os/signal"
 	"regexp"
@@ -121,6 +122,7 @@ type Terminal struct {
 	keepRight          bool
 	hscroll            bool
 	hscrollOff         int
+	scrollOff          int
 	wordRubout         string
 	wordNext           string
 	cx                 int
@@ -134,11 +136,13 @@ type Terminal struct {
 	toggleSort         bool
 	delimiter          Delimiter
 	expect             map[tui.Event]string
-	keymap       map[tui.Event][]action
+	keymap             map[tui.Event][]*action
 	pressed            string
 	printQuery         bool
 	history            *History
 	cycle              bool
+	headerFirst        bool
+	headerLines        int
 	header             []string
 	header0            []string
 	ansi               bool
@@ -167,6 +171,7 @@ type Terminal struct {
 	selected           map[int32]selectedItem
 	version            int64
 	reqBox             *util.EventBox
+	initialPreviewOpts previewOpts
 	previewOpts        previewOpts
 	previewer          previewer
 	previewed          previewed
@@ -213,6 +218,7 @@ const (
 	reqRefresh
 	reqReinit
 	reqRedraw
+	reqFullRedraw
 	reqClose
 	reqPrintQuery
 	reqPreviewEnqueue
@@ -283,6 +289,8 @@ const (
 	actTogglePreview
 	actTogglePreviewWrap
 	actPreview
+	actChangePreview
+	actChangePreviewWindow
 	actPreviewTop
 	actPreviewBottom
 	actPreviewUp
@@ -323,6 +331,7 @@ type searchRequest struct {
 type previewRequest struct {
 	template     string
 	pwindow      tui.Window
+	scrollOffset int
 	list         []*Item
 }
 
@@ -333,16 +342,16 @@ type previewResult struct {
 	spinner string
 }
 
-func toActions(types ...actionType) []action {
+func toActions(types ...actionType) []*action {
-	actions := make([]action, len(types))
+	actions := make([]*action, len(types))
 	for idx, t := range types {
-		actions[idx] = action{t: t, a: ""}
+		actions[idx] = &action{t: t, a: ""}
 	}
 	return actions
 }
 
-func defaultKeymap() map[tui.Event][]action {
+func defaultKeymap() map[tui.Event][]*action {
-	keymap := make(map[tui.Event][]action)
+	keymap := make(map[tui.Event][]*action)
 	add := func(e tui.EventType, a actionType) {
 		keymap[e.AsEvent()] = toActions(a)
 	}
@@ -413,7 +422,7 @@ func trimQuery(query string) []rune {
 func hasPreviewAction(opts *Options) bool {
 	for _, actions := range opts.Keymap {
 		for _, action := range actions {
-			if action.t == actPreview {
+			if action.t == actPreview || action.t == actChangePreview {
 				return true
 			}
 		}
@@ -502,6 +511,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		keepRight:          opts.KeepRight,
 		hscroll:            opts.Hscroll,
 		hscrollOff:         opts.HscrollOff,
+		scrollOff:          opts.ScrollOff,
 		wordRubout:         wordRubout,
 		wordNext:           wordNext,
 		cx:                 len(input),
@@ -527,6 +537,8 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		paused:             opts.Phony,
 		strong:             strongAttr,
 		cycle:              opts.Cycle,
+		headerFirst:        opts.HeaderFirst,
+		headerLines:        opts.HeaderLines,
 		header:             header,
 		header0:            header,
 		ansi:               opts.Ansi,
@@ -541,6 +553,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		merger:             EmptyMerger,
 		selected:           make(map[int32]selectedItem),
 		reqBox:             util.NewEventBox(),
+		initialPreviewOpts: opts.Preview,
 		previewOpts:        opts.Preview,
 		previewer:          previewer{0, []string{}, 0, showPreviewWindow, false, true, false, ""},
 		previewed:          previewed{0, 0, 0, false},
@@ -697,7 +710,7 @@ func (t *Terminal) sortSelected() []selectedItem {
 }
 
 func (t *Terminal) displayWidth(runes []rune) int {
-	width, _ := util.RunesWidth(runes, 0, t.tabstop, 0)
+	width, _ := util.RunesWidth(runes, 0, t.tabstop, math.MaxInt32)
 	return width
 }
 
@@ -974,12 +987,23 @@ func (t *Terminal) updatePromptOffset() ([]rune, []rune) {
 	return before, after
 }
 
+func (t *Terminal) promptLine() int {
+	if t.headerFirst {
+		max := t.window.Height() - 1
+		if !t.noInfoLine() {
+			max--
+		}
+		return util.Min(len(t.header0)+t.headerLines, max)
+	}
+	return 0
+}
+
 func (t *Terminal) placeCursor() {
-	t.move(0, t.promptLen+t.queryLen[0], false)
+	t.move(t.promptLine(), t.promptLen+t.queryLen[0], false)
 }
 
 func (t *Terminal) printPrompt() {
-	t.move(0, 0, true)
+	t.move(t.promptLine(), 0, true)
 	t.prompt()
 
 	before, after := t.updatePromptOffset()
@@ -1001,22 +1025,23 @@ func (t *Terminal) trimMessage(message string, maxWidth int) string {
 
 func (t *Terminal) printInfo() {
 	pos := 0
+	line := t.promptLine()
 	switch t.infoStyle {
 	case infoDefault:
-		t.move(1, 0, true)
+		t.move(line+1, 0, true)
 		if t.reading {
 			duration := int64(spinnerDuration)
 			idx := (time.Now().UnixNano() % (duration * int64(len(t.spinner)))) / duration
 			t.window.CPrint(tui.ColSpinner, t.spinner[idx])
 		}
-		t.move(1, 2, false)
+		t.move(line+1, 2, false)
 		pos = 2
 	case infoInline:
 		pos = t.promptLen + t.queryLen[0] + t.queryLen[1] + 1
 		if pos+len(" < ") > t.window.Width() {
 			return
 		}
-		t.move(0, pos, true)
+		t.move(line, pos, true)
 		if t.reading {
 			t.window.CPrint(tui.ColSpinner, " < ")
 		} else {
@@ -1059,11 +1084,20 @@ func (t *Terminal) printHeader() {
 		return
 	}
 	max := t.window.Height()
+	if t.headerFirst {
+		max--
+		if !t.noInfoLine() {
+			max--
+		}
+	}
 	var state *ansiState
 	for idx, lineStr := range t.header {
-		line := idx + 2
+		line := idx
-		if t.noInfoLine() {
+		if !t.headerFirst {
-			line--
+			line++
+			if !t.noInfoLine() {
+				line++
+			}
 		}
 		if line >= max {
 			continue
@@ -1164,7 +1198,7 @@ func (t *Terminal) printItem(result Result, line int, i int, current bool) {
 
 func (t *Terminal) trimRight(runes []rune, width int) ([]rune, bool) {
 	// We start from the beginning to handle tab characters
-	width, overflowIdx := util.RunesWidth(runes, 0, t.tabstop, width)
+	_, overflowIdx := util.RunesWidth(runes, 0, t.tabstop, width)
 	if overflowIdx >= 0 {
 		return runes[:overflowIdx], true
 	}
@@ -1615,9 +1649,14 @@ func (t *Terminal) replacePlaceholder(template string, forcePlus bool, input str
 		template, t.ansi, t.delimiter, t.printsep, forcePlus, input, list)
 }
 
-func (t *Terminal) evaluateScrollOffset(list []*Item, height int) int {
+func (t *Terminal) evaluateScrollOffset() int {
+	if t.pwindow == nil {
+		return 0
+	}
+
+	// We only need the current item to calculate the scroll offset
 	offsetExpr := offsetTrimCharsRegex.ReplaceAllString(
-		t.replacePlaceholder(t.previewOpts.scroll, false, "", list), "")
+		t.replacePlaceholder(t.previewOpts.scroll, false, "", []*Item{t.currentItem(), nil}), "")
 
 	atoi := func(s string) int {
 		n, e := strconv.Atoi(s)
@@ -1628,20 +1667,21 @@ func (t *Terminal) evaluateScrollOffset(list []*Item, height int) int {
 	}
 
 	base := -1
+	height := util.Max(0, t.pwindow.Height()-t.previewOpts.headerLines)
 	for _, component := range offsetComponentRegex.FindAllString(offsetExpr, -1) {
 		if strings.HasPrefix(component, "-/") {
 			component = component[1:]
 		}
 		if component[0] == '/' {
 			denom := atoi(component[1:])
-			if denom == 0 {
+			if denom != 0 {
-				return base
+				base -= height / denom
 			}
-			return base - height/denom
+			break
 		}
 		base += atoi(component)
 	}
-	return base
+	return util.Max(0, base)
 }
 
 func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, printsep string, forcePlus bool, query string, allItems []*Item) string {
@@ -1740,8 +1780,10 @@ func replacePlaceholder(template string, stripAnsi bool, delimiter Delimiter, pr
 	})
 }
 
-func (t *Terminal) redraw() {
+func (t *Terminal) redraw(clear bool) {
+	if clear {
 		t.tui.Clear()
+	}
 	t.tui.Refresh()
 	t.printAll()
 }
@@ -1761,7 +1803,7 @@ func (t *Terminal) executeCommand(template string, forcePlus bool, background bo
 		t.tui.Pause(true)
 		cmd.Run()
 		t.tui.Resume(true, false)
-		t.redraw()
+		t.redraw(true)
 		t.refresh()
 	} else {
 		t.tui.Pause(false)
@@ -1906,7 +1948,7 @@ func (t *Terminal) Loop() {
 		go func() {
 			for {
 				<-resizeChan
-				t.reqBox.Set(reqRedraw, nil)
+				t.reqBox.Set(reqFullRedraw, nil)
 			}
 		}()
 
@@ -1945,12 +1987,14 @@ func (t *Terminal) Loop() {
 				var items []*Item
 				var commandTemplate string
 				var pwindow tui.Window
+				initialOffset := 0
 				t.previewBox.Wait(func(events *util.Events) {
 					for req, value := range *events {
 						switch req {
 						case reqPreviewEnqueue:
 							request := value.(previewRequest)
 							commandTemplate = request.template
+							initialOffset = request.scrollOffset
 							items = request.list
 							pwindow = request.pwindow
 						}
@@ -1962,11 +2006,9 @@ func (t *Terminal) Loop() {
 				if items[0] != nil {
 					_, query := t.Input()
 					command := t.replacePlaceholder(commandTemplate, false, string(query), items)
-					initialOffset := 0
 					cmd := util.ExecCommand(command, true)
 					if pwindow != nil {
 						height := pwindow.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())
@@ -2101,7 +2143,7 @@ func (t *Terminal) Loop() {
 		if len(command) > 0 && t.isPreviewEnabled() {
 			_, list := t.buildPlusList(command, false)
 			t.cancelPreview()
-			t.previewBox.Set(reqPreviewEnqueue, previewRequest{command, t.pwindow, list})
+			t.previewBox.Set(reqPreviewEnqueue, previewRequest{command, t.pwindow, t.evaluateScrollOffset(), list})
 		}
 	}
 
@@ -2156,9 +2198,11 @@ func (t *Terminal) Loop() {
 						t.suppress = false
 					case reqReinit:
 						t.tui.Resume(t.fullscreen, t.sigstop)
-						t.redraw()
+						t.redraw(true)
 					case reqRedraw:
-						t.redraw()
+						t.redraw(false)
+					case reqFullRedraw:
+						t.redraw(true)
 					case reqClose:
 						exit(func() int {
 							if t.output() {
@@ -2226,13 +2270,15 @@ func (t *Terminal) Loop() {
 				}
 			}
 		}
-		togglePreview := func(enabled bool) {
+		togglePreview := func(enabled bool) bool {
 			if t.previewer.enabled != enabled {
 				t.previewer.enabled = enabled
-				t.tui.Clear()
+				// We need to immediately update t.pwindow so we don't use reqRedraw
 				t.resizeWindows()
 				req(reqPrompt, reqList, reqInfo, reqHeader)
+				return true
 			}
+			return false
 		}
 		toggle := func() bool {
 			current := t.currentItem()
@@ -2269,12 +2315,12 @@ func (t *Terminal) Loop() {
 			}
 		}
 
-		actionsFor := func(eventType tui.EventType) []action {
+		actionsFor := func(eventType tui.EventType) []*action {
 			return t.keymap[eventType.AsEvent()]
 		}
 
-		var doAction func(action) bool
+		var doAction func(*action) bool
-		doActions := func(actions []action) bool {
+		doActions := func(actions []*action) bool {
 			for _, action := range actions {
 				if !doAction(action) {
 					return false
@@ -2282,7 +2328,7 @@ func (t *Terminal) Loop() {
 			}
 			return true
 		}
-		doAction = func(a action) bool {
+		doAction = func(a *action) bool {
 			switch a.t {
 			case actIgnore:
 			case actExecute, actExecuteSilent:
@@ -2300,7 +2346,7 @@ func (t *Terminal) Loop() {
 						if valid {
 							t.cancelPreview()
 							t.previewBox.Set(reqPreviewEnqueue,
-								previewRequest{t.previewOpts.command, t.pwindow, list})
+								previewRequest{t.previewOpts.command, t.pwindow, t.evaluateScrollOffset(), list})
 						}
 					}
 				}
@@ -2462,14 +2508,14 @@ func (t *Terminal) Loop() {
 				}
 			case actToggleIn:
 				if t.layout != layoutDefault {
-					return doAction(action{t: actToggleUp})
+					return doAction(&action{t: actToggleUp})
 				}
-				return doAction(action{t: actToggleDown})
+				return doAction(&action{t: actToggleDown})
 			case actToggleOut:
 				if t.layout != layoutDefault {
-					return doAction(action{t: actToggleDown})
+					return doAction(&action{t: actToggleDown})
 				}
-				return doAction(action{t: actToggleUp})
+				return doAction(&action{t: actToggleUp})
 			case actToggleDown:
 				if t.multi > 0 && t.merger.Length() > 0 && toggle() {
 					t.vmove(-1, true)
@@ -2493,7 +2539,7 @@ func (t *Terminal) Loop() {
 					req(reqClose)
 				}
 			case actClearScreen:
-				req(reqRedraw)
+				req(reqFullRedraw)
 			case actClearQuery:
 				t.input = []rune{}
 				t.cx = 0
@@ -2642,7 +2688,7 @@ func (t *Terminal) Loop() {
 							}
 						}
 					} else if me.Down {
-						if my == 0 && mx >= 0 {
+						if my == t.promptLine() && mx >= 0 {
 							// Prompt
 							t.cx = mx + t.xoffset
 						} else if my >= min {
@@ -2673,12 +2719,52 @@ func (t *Terminal) Loop() {
 					command := t.replacePlaceholder(a.a, false, string(t.input), list)
 					newCommand = &command
 					t.reading = true
+					t.version++
 				}
 			case actUnbind:
 				keys := parseKeyChords(a.a, "PANIC")
 				for key := range keys {
 					delete(t.keymap, key)
 				}
+			case actChangePreview:
+				if t.previewOpts.command != a.a {
+					togglePreview(len(a.a) > 0)
+					t.previewOpts.command = a.a
+					refreshPreview(t.previewOpts.command)
+				}
+			case actChangePreviewWindow:
+				currentPreviewOpts := t.previewOpts
+
+				// Reset preview options and apply the additional options
+				t.previewOpts = t.initialPreviewOpts
+
+				// Split window options
+				tokens := strings.Split(a.a, "|")
+				parsePreviewWindow(&t.previewOpts, tokens[0])
+				if len(tokens) > 1 {
+					a.a = strings.Join(append(tokens[1:], tokens[0]), "|")
+				}
+
+				if t.previewOpts.hidden {
+					togglePreview(false)
+				} else {
+					// Full redraw
+					if !currentPreviewOpts.sameLayout(t.previewOpts) {
+						if togglePreview(true) {
+							refreshPreview(t.previewOpts.command)
+						} else {
+							req(reqRedraw)
+						}
+					} else if !currentPreviewOpts.sameContentLayout(t.previewOpts) {
+						t.previewed.version = 0
+						req(reqPreviewRefresh)
+					}
+
+					// Adjust scroll offset
+					if t.hasPreviewWindow() && currentPreviewOpts.scroll != t.previewOpts.scroll {
+						scrollPreviewTo(t.evaluateScrollOffset())
+					}
+				}
 			}
 			return true
 		}
@@ -2686,7 +2772,7 @@ func (t *Terminal) Loop() {
 		if t.jumping == jumpDisabled {
 			actions := t.keymap[event.Comparable()]
 			if len(actions) == 0 && event.Type == tui.Rune {
-				doAction(action{t: actRune})
+				doAction(&action{t: actRune})
 			} else if !doActions(actions) {
 				continue
 			}
@@ -2748,9 +2834,26 @@ func (t *Terminal) constrain() {
 
 	t.cy = util.Constrain(t.cy, 0, count-1)
 
-	minOffset := t.cy - height + 1
+	minOffset := util.Max(t.cy-height+1, 0)
 	maxOffset := util.Max(util.Min(count-height, t.cy), 0)
 	t.offset = util.Constrain(t.offset, minOffset, maxOffset)
+	if t.scrollOff == 0 {
+		return
+	}
+
+	scrollOff := util.Min(height/2, t.scrollOff)
+	for {
+		prevOffset := t.offset
+		if t.cy-t.offset < scrollOff {
+			t.offset = util.Max(minOffset, t.offset-1)
+		}
+		if t.cy-t.offset >= height-scrollOff {
+			t.offset = util.Min(maxOffset, t.offset+1)
+		}
+		if t.offset == prevOffset {
+			break
+		}
+	}
 }
 
 func (t *Terminal) vmove(o int, allowCycle bool) {

src/terminal_test.go

@@ -288,6 +288,7 @@ func TestUnixCommands(t *testing.T) {
 		{give{`grep {} ~/test`, ``, newItems(`~`)}, want{output: `grep '~' ~/test`}},
 
 		// 2) problematic examples
+		// (not necessarily unexpected)
 
 		// paths that need to expand some part of it won't work (special characters and variables)
 		{give{`cat {}`, ``, newItems(`~/test`)}, want{output: `cat '~/test'`}},
@@ -315,6 +316,7 @@ func TestWindowsCommands(t *testing.T) {
 		{give{`rg -- {}`, ``, newItems(`"C:\test.txt"`)}, want{output: `rg -- ^"\^"C:\\test.txt\^"^"`}},
 
 		// 2) problematic examples
+		// (not necessarily unexpected)
 
 		// notepad++'s parser can't handle `-n"12"` generate by fzf, expects `-n12`
 		{give{`notepad++ -n{1} {2}`, ``, newItems(`12	C:\Work\Test Folder\File.txt`)}, want{output: `notepad++ -n^"12^" ^"C:\\Work\\Test Folder\\File.txt^"`}},
@@ -327,11 +329,97 @@ func TestWindowsCommands(t *testing.T) {
 
 		// the "file" flag in the pattern won't create *.bat or *.cmd file so the command in the output tries to edit the file, instead of executing it
 		// the temp file contains: `cat "C:\test.txt"`
+		// TODO this should actually work
 		{give{`cmd /c {f}`, ``, newItems(`cat "C:\test.txt"`)}, want{match: `^cmd /c .*\fzf-preview-[0-9]{9}$`}},
 	}
 	testCommands(t, tests)
 }
 
+// purpose of this test is to demonstrate some shortcomings of fzf's templating system on Windows in Powershell
+func TestPowershellCommands(t *testing.T) {
+	if !util.IsWindows() {
+		t.SkipNow()
+	}
+
+	tests := []testCase{
+		// reference: give{template, query, items}, want{output OR match}
+
+		/*
+			You can read each line in the following table as a pipeline that
+			consist of series of parsers that act upon your input (col. 1) and
+			each cell represents the output value.
+
+			For example:
+			 - exec.Command("program.exe", `\''`)
+			   - goes to win32 api which will process it transparently as it contains no special characters, see [CommandLineToArgvW][].
+			     - powershell command will receive it as is, that is two arguments: a literal backslash and empty string in single quotes
+			     - native command run via/from powershell will receive only one argument: a literal backslash. Because extra parsing rules apply, see [NativeCallsFromPowershell][].
+			       - some¹ apps have internal parser, that requires one more level of escaping (yes, this is completely application-specific, but see terminal_test.go#TestWindowsCommands)
+
+			Character⁰   CommandLineToArgvW   Powershell commands              Native commands from Powershell   Apps requiring escapes¹    | Being tested below
+			----------   ------------------   ------------------------------   -------------------------------   -------------------------- | ------------------
+			"            empty string²        missing argument error           ...                               ...                        |
+			\"           literal "            unbalanced quote error           ...                               ...                        |
+			'\"'         literal '"'          literal "                        empty string                      empty string (match all)   | yes
+			'\\\"'       literal '\"'         literal \"                       literal "                         literal "                  |
+			----------   ------------------   ------------------------------   -------------------------------   -------------------------- | ------------------
+			\            transparent          transparent                      transparent                       regex error                |
+			'\'          transparent          literal \                        literal \                         regex error                | yes
+			\\           transparent          transparent                      transparent                       literal \                  |
+			'\\'         transparent          literal \\                       literal \\                        literal \                  |
+			----------   ------------------   ------------------------------   -------------------------------   -------------------------- | ------------------
+			'            transparent          unbalanced quote error           ...                               ...                        |
+			\'           transparent          literal \ and unb. quote error   ...                               ...                        |
+			\''          transparent          literal \ and empty string       literal \                         regex error                | no, but given as example above
+			'''          transparent          unbalanced quote error           ...                               ...                        |
+			''''         transparent          literal '                        literal '                         literal '                  | yes
+			----------   ------------------   ------------------------------   -------------------------------   -------------------------- | ------------------
+
+			⁰: charatecter or characters 'x' as an argument to a program in go's call: exec.Command("program.exe", `x`)
+			¹: native commands like grep, git grep, ripgrep
+			²: interpreted as a grouping quote, affects argument parser and gets removed from the result
+
+			[CommandLineToArgvW]: https://docs.microsoft.com/en-gb/windows/win32/api/shellapi/nf-shellapi-commandlinetoargvw#remarks
+			[NativeCallsFromPowershell]: https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_parsing?view=powershell-7.1#passing-arguments-that-contain-quote-characters
+		*/
+
+		// 1) working examples
+
+		{give{`Get-Content {}`, ``, newItems(`C:\test.txt`)}, want{output: `Get-Content 'C:\test.txt'`}},
+		{give{`rg -- "package" {}`, ``, newItems(`.\test.go`)}, want{output: `rg -- "package" '.\test.go'`}},
+
+		// example of escaping single quotes
+		{give{`rg -- {}`, ``, newItems(`'foobar'`)}, want{output: `rg -- '''foobar'''`}},
+
+		// chaining powershells
+		{give{`powershell -NoProfile -Command {}`, ``, newItems(`cat "C:\test.txt"`)}, want{output: `powershell -NoProfile -Command 'cat \"C:\test.txt\"'`}},
+
+		// 2) problematic examples
+		// (not necessarily unexpected)
+
+		// looking for a path string will only work with escaped backslashes
+		{give{`rg -- {}`, ``, newItems(`C:\test.txt`)}, want{output: `rg -- 'C:\test.txt'`}},
+		// looking for a literal double quote will only work with triple escaped double quotes
+		{give{`rg -- {}`, ``, newItems(`"C:\test.txt"`)}, want{output: `rg -- '\"C:\test.txt\"'`}},
+
+		// Get-Content (i.e. cat alias) is parsing `"` as a part of the file path, returns an error:
+		// Get-Content : Cannot find drive. A drive with the name '"C:' does not exist.
+		{give{`cat {}`, ``, newItems(`"C:\test.txt"`)}, want{output: `cat '\"C:\test.txt\"'`}},
+
+		// the "file" flag in the pattern won't create *.ps1 file so the powershell will offload this "unknown" filetype
+		// to explorer, which will prompt user to pick editing program for the fzf-preview file
+		// the temp file contains: `cat "C:\test.txt"`
+		// TODO this should actually work
+		{give{`powershell -NoProfile -Command {f}`, ``, newItems(`cat "C:\test.txt"`)}, want{match: `^powershell -NoProfile -Command .*\fzf-preview-[0-9]{9}$`}},
+	}
+
+	// to force powershell-style escaping we temporarily set environment variable that fzf honors
+	shellBackup := os.Getenv("SHELL")
+	os.Setenv("SHELL", "powershell")
+	testCommands(t, tests)
+	os.Setenv("SHELL", shellBackup)
+}
+
 /*
 	Test typical valid placeholders and parsing of them.
 

src/terminal_windows.go

@@ -21,10 +21,25 @@ func notifyOnCont(resizeChan chan<- os.Signal) {
 }
 
 func quoteEntry(entry string) string {
+	shell := os.Getenv("SHELL")
+	if len(shell) == 0 {
+		shell = "cmd"
+	}
+
+	if strings.Contains(shell, "cmd") {
+		// backslash escaping is done here for applications
+		// (see ripgrep test case in terminal_test.go#TestWindowsCommands)
 		escaped := strings.Replace(entry, `\`, `\\`, -1)
 		escaped = `"` + strings.Replace(escaped, `"`, `\"`, -1) + `"`
+		// caret is the escape character for cmd shell
 		r, _ := regexp.Compile(`[&|<>()@^%!"]`)
 		return r.ReplaceAllStringFunc(escaped, func(match string) string {
 			return "^" + match
 		})
+	} else if strings.Contains(shell, "pwsh") || strings.Contains(shell, "powershell") {
+		escaped := strings.Replace(entry, `"`, `\"`, -1)
+		return "'" + strings.Replace(escaped, "'", "''", -1) + "'"
+	} else {
+		return "'" + strings.Replace(entry, "'", "'\\''", -1) + "'"
+	}
 }

src/util/util.go

@@ -26,7 +26,7 @@ func RunesWidth(runes []rune, prefixWidth int, tabstop int, limit int) (int, int
 			w = runewidth.StringWidth(s) + strings.Count(s, "\n")
 		}
 		width += w
-		if limit > 0 && width > limit {
+		if width > limit {
 			return width, idx
 		}
 		idx += len(rs)

src/util/util_test.go

@@ -38,3 +38,19 @@ func TestOnce(t *testing.T) {
 		t.Error("Expected: false")
 	}
 }
+
+func TestRunesWidth(t *testing.T) {
+	for _, args := range [][]int{
+		{100, 5, -1},
+		{3, 4, 3},
+		{0, 1, 0},
+	} {
+		width, overflowIdx := RunesWidth([]rune("hello"), 0, 0, args[0])
+		if width != args[1] {
+			t.Errorf("Expected width: %d, actual: %d", args[1], width)
+		}
+		if overflowIdx != args[2] {
+			t.Errorf("Expected overflow index: %d, actual: %d", args[2], overflowIdx)
+		}
+	}
+}

src/util/util_windows.go

@@ -6,26 +6,60 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
+	"strings"
+	"sync/atomic"
 	"syscall"
 )
 
-// ExecCommand executes the given command with cmd
+var shellPath atomic.Value
+
+// ExecCommand executes the given command with $SHELL
 func ExecCommand(command string, setpgid bool) *exec.Cmd {
-	return ExecCommandWith("cmd", command, setpgid)
+	var shell string
+	if cached := shellPath.Load(); cached != nil {
+		shell = cached.(string)
+	} else {
+		shell = os.Getenv("SHELL")
+		if len(shell) == 0 {
+			shell = "cmd"
+		} else if strings.Contains(shell, "/") {
+			out, err := exec.Command("cygpath", "-w", shell).Output()
+			if err == nil {
+				shell = strings.Trim(string(out), "\n")
+			}
+		}
+		shellPath.Store(shell)
+	}
+	return ExecCommandWith(shell, command, setpgid)
 }
 
-// ExecCommandWith executes the given command with cmd. _shell parameter is
+// ExecCommandWith executes the given command with the specified shell
-// ignored on Windows.
 // FIXME: setpgid is unused. We set it in the Unix implementation so that we
 // can kill preview process with its child processes at once.
-func ExecCommandWith(_shell string, command string, setpgid bool) *exec.Cmd {
+// NOTE: For "powershell", we should ideally set output encoding to UTF8,
-	cmd := exec.Command("cmd")
+// but it is left as is now because no adverse effect has been observed.
+func ExecCommandWith(shell string, command string, setpgid bool) *exec.Cmd {
+	var cmd *exec.Cmd
+	if strings.Contains(shell, "cmd") {
+		cmd = exec.Command(shell)
 		cmd.SysProcAttr = &syscall.SysProcAttr{
 			HideWindow:    false,
 			CmdLine:       fmt.Sprintf(` /v:on/s/c "%s"`, command),
 			CreationFlags: 0,
 		}
 		return cmd
+	}
+
+	if strings.Contains(shell, "pwsh") || strings.Contains(shell, "powershell") {
+		cmd = exec.Command(shell, "-NoProfile", "-Command", command)
+	} else {
+		cmd = exec.Command(shell, "-c", command)
+	}
+	cmd.SysProcAttr = &syscall.SysProcAttr{
+		HideWindow:    false,
+		CreationFlags: 0,
+	}
+	return cmd
 }
 
 // KillCommand kills the process for the given command

test/test_go.rb

@@ -2069,6 +2069,145 @@ class TestGoFZF < TestBase
     tmux.send_keys :Up
     tmux.until { |lines| assert_includes lines[1], '[[99]]' }
   end
+
+  def test_reload_should_update_preview
+    tmux.send_keys "seq 3 | #{FZF} --bind 'ctrl-t:reload:echo 4' --preview 'echo {}' --preview-window 'nohidden'", :Enter
+    tmux.until { |lines| assert_includes lines[1], '1' }
+    tmux.send_keys 'C-t'
+    tmux.until { |lines| assert_includes lines[1], '4' }
+  end
+
+  def test_scroll_off
+    tmux.send_keys "seq 1000 | #{FZF} --scroll-off=3 --bind l:last", :Enter
+    tmux.until { |lines| assert_equal 1000, lines.item_count }
+    height = tmux.until { |lines| lines }.first.to_i
+    tmux.send_keys :PgUp
+    tmux.until do |lines|
+      assert_equal height + 3, lines.first.to_i
+      assert_equal "> #{height}", lines[3].strip
+    end
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_equal "> #{height + 1}", lines[3].strip }
+    tmux.send_keys 'l'
+    tmux.until { |lines| assert_equal '> 1000', lines.first.strip }
+    tmux.send_keys :PgDn
+    tmux.until { |lines| assert_equal "> #{1000 - height + 1}", lines.reverse[5].strip }
+    tmux.send_keys :Down
+    tmux.until { |lines| assert_equal "> #{1000 - height}", lines.reverse[5].strip }
+  end
+
+  def test_scroll_off_large
+    tmux.send_keys "seq 1000 | #{FZF} --scroll-off=9999", :Enter
+    tmux.until { |lines| assert_equal 1000, lines.item_count }
+    height = tmux.until { |lines| lines }.first.to_i
+    tmux.send_keys :PgUp
+    tmux.until { |lines| assert_equal "> #{height}", lines[height / 2].strip }
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_equal "> #{height + 1}", lines[height / 2].strip }
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_equal "> #{height + 2}", lines[height / 2].strip }
+    tmux.send_keys :Down
+    tmux.until { |lines| assert_equal "> #{height + 1}", lines[height / 2].strip }
+  end
+
+  def test_header_first
+    tmux.send_keys "seq 1000 | #{FZF} --header foobar --header-lines 3 --header-first", :Enter
+    tmux.until do |lines|
+      expected = <<~OUTPUT
+        > 4
+          997/997
+        >
+          3
+          2
+          1
+          foobar
+      OUTPUT
+
+      assert_equal expected.chomp, lines.reverse.take(7).reverse.join("\n")
+    end
+  end
+
+  def test_header_first_reverse
+    tmux.send_keys "seq 1000 | #{FZF} --header foobar --header-lines 3 --header-first --reverse --inline-info", :Enter
+    tmux.until do |lines|
+      expected = <<~OUTPUT
+          foobar
+          1
+          2
+          3
+        >   < 997/997
+        > 4
+      OUTPUT
+
+      assert_equal expected.chomp, lines.take(6).join("\n")
+    end
+  end
+
+  def test_change_preview_window
+    tmux.send_keys "seq 1000 | #{FZF} --preview 'echo [[{}]]' --preview-window border-none --bind '" \
+      'a:change-preview(echo __{}__),' \
+      'b:change-preview-window(down)+change-preview(echo =={}==)+change-preview-window(up),' \
+      'c:change-preview(),d:change-preview-window(hidden),' \
+      "e:preview(printf ::%${FZF_PREVIEW_COLUMNS}s{})+change-preview-window(up),f:change-preview-window(up,wrap)'", :Enter
+    tmux.until { |lines| assert_equal 1000, lines.item_count }
+    tmux.until { |lines| assert_includes lines[0], '[[1]]' }
+
+    # change-preview action permanently changes the preview command set by --preview
+    tmux.send_keys 'a'
+    tmux.until { |lines| assert_includes lines[0], '__1__' }
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_includes lines[0], '__2__' }
+
+    # When multiple change-preview-window actions are bound to a single key,
+    # the last one wins and the updated options are immediately applied to the new preview
+    tmux.send_keys 'b'
+    tmux.until { |lines| assert_equal '==2==', lines[0] }
+    tmux.send_keys :Up
+    tmux.until { |lines| assert_equal '==3==', lines[0] }
+
+    # change-preview with an empty preview command closes the preview window
+    tmux.send_keys 'c'
+    tmux.until { |lines| refute_includes lines[0], '==' }
+
+    # change-preview again to re-open the preview window
+    tmux.send_keys 'a'
+    tmux.until { |lines| assert_equal '__3__', lines[0] }
+
+    # Hide the preview window with hidden flag
+    tmux.send_keys 'd'
+    tmux.until { |lines| refute_includes lines[0], '__3__' }
+
+    # One-off preview
+    tmux.send_keys 'e'
+    tmux.until do |lines|
+      assert_equal '::', lines[0]
+      refute_includes lines[1], '3'
+    end
+
+    # Wrapped
+    tmux.send_keys 'f'
+    tmux.until do |lines|
+      assert_equal '::', lines[0]
+      assert_equal '  3', lines[1]
+    end
+  end
+
+  def test_change_preview_window_rotate
+    tmux.send_keys "seq 100 | #{FZF} --preview-window left,border-none --preview 'echo hello' --bind '" \
+      "a:change-preview-window(right|down|up|hidden|)'", :Enter
+    3.times do
+      tmux.until { |lines| lines[0].start_with?('hello') }
+      tmux.send_keys 'a'
+      tmux.until { |lines| lines[0].end_with?('hello') }
+      tmux.send_keys 'a'
+      tmux.until { |lines| lines[-1].start_with?('hello') }
+      tmux.send_keys 'a'
+      tmux.until { |lines| assert_equal 'hello', lines[0] }
+      tmux.send_keys 'a'
+      tmux.until { |lines| refute_includes lines[0], 'hello' }
+      tmux.send_keys 'a'
+    end
+  end
 end
 
 module TestShell