0.28.0

fzf --bind 'space:preview(date)+put'

Close #2456

CHANGELOG.md

@@ -1,6 +1,24 @@
 CHANGELOG
 =========
 
+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

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
 

install

@@ -2,7 +2,7 @@
 
 set -u
 
-version=0.27.3
+version=0.28.0
 auto_completion=
 key_bindings=
 update_config=2

install.ps1

@@ -1,4 +1,4 @@
-$version="0.27.3"
+$version="0.28.0"
 
 $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 = "0.28"
 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 "Nov 2021" "fzf 0.28.0" "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 "Nov 2021" "fzf 0.28.0" "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"
@@ -853,6 +860,7 @@ 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)

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

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
@@ -200,6 +203,7 @@ type Options struct {
 	KeepRight   bool
 	Hscroll     bool
 	HscrollOff  int
+	ScrollOff   int
 	FileWord    bool
 	InfoStyle   infoStyle
 	JumpLabels  string
@@ -222,6 +226,7 @@ type Options struct {
 	History     *History
 	Header      []string
 	HeaderLines int
+	HeaderFirst bool
 	Margin      [4]sizeSpec
 	Padding     [4]sizeSpec
 	BorderShape tui.BorderShape
@@ -261,6 +266,7 @@ func defaultOptions() *Options {
 		KeepRight:   false,
 		Hscroll:     true,
 		HscrollOff:  10,
+		ScrollOff:   0,
 		FileWord:    false,
 		InfoStyle:   infoDefault,
 		JumpLabels:  defaultJumpLabels,
@@ -283,6 +289,7 @@ func defaultOptions() *Options {
 		History:     nil,
 		Header:      make([]string, 0),
 		HeaderLines: 0,
+		HeaderFirst: false,
 		Margin:      defaultMargin(),
 		Padding:     defaultMargin(),
 		Unicode:     true,
@@ -974,6 +981,12 @@ 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 {
@@ -1354,6 +1367,8 @@ 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 +1436,10 @@ 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 +1549,8 @@ 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 +1568,10 @@ 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")
 	}

src/terminal.go

@@ -121,6 +121,7 @@ type Terminal struct {
 	keepRight    bool
 	hscroll      bool
 	hscrollOff   int
+	scrollOff    int
 	wordRubout   string
 	wordNext     string
 	cx           int
@@ -139,6 +140,8 @@ type Terminal struct {
 	printQuery   bool
 	history      *History
 	cycle        bool
+	headerFirst  bool
+	headerLines  int
 	header       []string
 	header0      []string
 	ansi         bool
@@ -502,6 +505,7 @@ 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 +531,8 @@ 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,
@@ -974,12 +980,23 @@ 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 +1018,23 @@ 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 +1077,20 @@ 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
-		if t.noInfoLine() {
-			line--
+		line := idx
+		if !t.headerFirst {
+			line++
+			if !t.noInfoLine() {
+				line++
+			}
 		}
 		if line >= max {
 			continue
@@ -2642,7 +2669,7 @@ 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 {
@@ -2673,6 +2700,7 @@ 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")
@@ -2748,9 +2776,26 @@ 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 {
-	escaped := strings.Replace(entry, `\`, `\\`, -1)
-	escaped = `"` + strings.Replace(escaped, `"`, `\"`, -1) + `"`
-	r, _ := regexp.Compile(`[&|<>()@^%!"]`)
-	return r.ReplaceAllStringFunc(escaped, func(match string) string {
-		return "^" + match
-	})
+	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_windows.go

@@ -6,23 +6,57 @@ 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
-// ignored on Windows.
+// ExecCommandWith executes the given command with the specified shell
 // 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 {
-	cmd := exec.Command("cmd")
+// NOTE: For "powershell", we should ideally set output encoding to UTF8,
+// 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,
-		CmdLine:       fmt.Sprintf(` /v:on/s/c "%s"`, command),
 		CreationFlags: 0,
 	}
 	return cmd

test/test_go.rb

@@ -2069,6 +2069,79 @@ 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
 end
 
 module TestShell