Add --print0 option

Related: #660

CHANGELOG.md

@@ -7,6 +7,8 @@ CHANGELOG
     - Added `--algo=[v1|v2]` option so one can still choose the old algorithm
       which values the search performance over the quality of the result
 - Advanced scoring criteria
+- `--read0` to read input delimited by ASCII NUL character
+- `--print0` to print output delimited by ASCII NUL character
 
 0.13.5
 ------

man/man1/fzf.1

@@ -285,6 +285,12 @@ with the default enter key.
 e.g. \fBfzf --expect=ctrl-v,ctrl-t,alt-s,f1,f2,~,@\fR
 .RE
 .TP
+.B "--read0"
+Read input delimited by ASCII NUL character instead of newline character
+.TP
+.B "--print0"
+Print output delimited by ASCII NUL character instead of newline character
+.TP
 .B "--sync"
 Synchronous search for multi-staged filtering. If specified, fzf will launch
 ncurses finder only after the input stream is complete.

src/core.go

@@ -151,7 +151,7 @@ func Run(opts *Options) {
 	// Filtering mode
 	if opts.Filter != nil {
 		if opts.PrintQuery {
-			fmt.Println(*opts.Filter)
+			opts.Printer(*opts.Filter)
 		}
 
 		pattern := patternBuilder([]rune(*opts.Filter))
@@ -164,7 +164,7 @@ func Run(opts *Options) {
 					item := chunkList.trans(runes, 0)
 					if item != nil {
 						if result, _, _ := pattern.MatchItem(item, false, slab); result != nil {
-							fmt.Println(item.text.ToString())
+							opts.Printer(item.text.ToString())
 							found = true
 						}
 					}
@@ -180,7 +180,7 @@ func Run(opts *Options) {
 				chunks:  snapshot,
 				pattern: pattern})
 			for i := 0; i < merger.Length(); i++ {
-				fmt.Println(merger.Get(i).item.AsString(opts.Ansi))
+				opts.Printer(merger.Get(i).item.AsString(opts.Ansi))
 				found = true
 			}
 		}
@@ -254,13 +254,13 @@ func Run(opts *Options) {
 							} else if val.final {
 								if opts.Exit0 && count == 0 || opts.Select1 && count == 1 {
 									if opts.PrintQuery {
-										fmt.Println(opts.Query)
+										opts.Printer(opts.Query)
 									}
 									if len(opts.Expect) > 0 {
-										fmt.Println()
+										opts.Printer("")
 									}
 									for i := 0; i < count; i++ {
-										fmt.Println(val.Get(i).item.AsString(opts.Ansi))
+										opts.Printer(val.Get(i).item.AsString(opts.Ansi))
 									}
 									if count > 0 {
 										os.Exit(exitOk)

src/options.go

@@ -162,6 +162,7 @@ type Options struct {
 	Preview     previewOpts
 	PrintQuery  bool
 	ReadZero    bool
+	Printer     func(string)
 	Sync        bool
 	History     *History
 	Header      []string
@@ -206,6 +207,7 @@ func defaultOptions() *Options {
 		Preview:     previewOpts{"", posRight, sizeSpec{50, true}, false},
 		PrintQuery:  false,
 		ReadZero:    false,
+		Printer:     func(str string) { fmt.Println(str) },
 		Sync:        false,
 		History:     nil,
 		Header:      make([]string, 0),
@@ -935,6 +937,10 @@ func parseOptions(opts *Options, allArgs []string) {
 			opts.ReadZero = true
 		case "--no-read0":
 			opts.ReadZero = false
+		case "--print0":
+			opts.Printer = func(str string) { fmt.Print(str, "\x00") }
+		case "--no-print0":
+			opts.Printer = func(str string) { fmt.Println(str) }
 		case "--print-query":
 			opts.PrintQuery = true
 		case "--no-print-query":

src/terminal.go

@@ -63,6 +63,7 @@ type Terminal struct {
 	reading    bool
 	jumping    jumpMode
 	jumpLabels string
+	printer    func(string)
 	merger     *Merger
 	selected   map[int32]selectedItem
 	reqBox     *util.EventBox
@@ -269,6 +270,7 @@ func NewTerminal(opts *Options, eventBox *util.EventBox) *Terminal {
 		reading:    true,
 		jumping:    jumpDisabled,
 		jumpLabels: opts.JumpLabels,
+		printer:    opts.Printer,
 		merger:     EmptyMerger,
 		selected:   make(map[int32]selectedItem),
 		reqBox:     util.NewEventBox(),
@@ -347,21 +349,21 @@ func (t *Terminal) UpdateList(merger *Merger) {
 
 func (t *Terminal) output() bool {
 	if t.printQuery {
-		fmt.Println(string(t.input))
+		t.printer(string(t.input))
 	}
 	if len(t.expect) > 0 {
-		fmt.Println(t.pressed)
+		t.printer(t.pressed)
 	}
 	found := len(t.selected) > 0
 	if !found {
 		cnt := t.merger.Length()
 		if cnt > 0 && cnt > t.cy {
-			fmt.Println(t.current())
+			t.printer(t.current())
 			found = true
 		}
 	} else {
 		for _, sel := range t.sortSelected() {
-			fmt.Println(sel.text)
+			t.printer(sel.text)
 		}
 	}
 	return found
@@ -1028,7 +1030,7 @@ func (t *Terminal) Loop() {
 						t.printPreview()
 					case reqPrintQuery:
 						C.Close()
-						fmt.Println(string(t.input))
+						t.printer(string(t.input))
 						exit(exitOk)
 					case reqQuit:
 						C.Close()