diff options
Diffstat (limited to 'vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/ssh/terminal/terminal.go')
| -rw-r--r-- | vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/ssh/terminal/terminal.go | 951 |
1 files changed, 951 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/ssh/terminal/terminal.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/ssh/terminal/terminal.go new file mode 100644 index 000000000..18379a935 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/ssh/terminal/terminal.go @@ -0,0 +1,951 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package terminal + +import ( + "bytes" + "io" + "sync" + "unicode/utf8" +) + +// EscapeCodes contains escape sequences that can be written to the terminal in +// order to achieve different styles of text. +type EscapeCodes struct { + // Foreground colors + Black, Red, Green, Yellow, Blue, Magenta, Cyan, White []byte + + // Reset all attributes + Reset []byte +} + +var vt100EscapeCodes = EscapeCodes{ + Black: []byte{keyEscape, '[', '3', '0', 'm'}, + Red: []byte{keyEscape, '[', '3', '1', 'm'}, + Green: []byte{keyEscape, '[', '3', '2', 'm'}, + Yellow: []byte{keyEscape, '[', '3', '3', 'm'}, + Blue: []byte{keyEscape, '[', '3', '4', 'm'}, + Magenta: []byte{keyEscape, '[', '3', '5', 'm'}, + Cyan: []byte{keyEscape, '[', '3', '6', 'm'}, + White: []byte{keyEscape, '[', '3', '7', 'm'}, + + Reset: []byte{keyEscape, '[', '0', 'm'}, +} + +// Terminal contains the state for running a VT100 terminal that is capable of +// reading lines of input. +type Terminal struct { + // AutoCompleteCallback, if non-null, is called for each keypress with + // the full input line and the current position of the cursor (in + // bytes, as an index into |line|). If it returns ok=false, the key + // press is processed normally. Otherwise it returns a replacement line + // and the new cursor position. + AutoCompleteCallback func(line string, pos int, key rune) (newLine string, newPos int, ok bool) + + // Escape contains a pointer to the escape codes for this terminal. + // It's always a valid pointer, although the escape codes themselves + // may be empty if the terminal doesn't support them. + Escape *EscapeCodes + + // lock protects the terminal and the state in this object from + // concurrent processing of a key press and a Write() call. + lock sync.Mutex + + c io.ReadWriter + prompt []rune + + // line is the current line being entered. + line []rune + // pos is the logical position of the cursor in line + pos int + // echo is true if local echo is enabled + echo bool + // pasteActive is true iff there is a bracketed paste operation in + // progress. + pasteActive bool + + // cursorX contains the current X value of the cursor where the left + // edge is 0. cursorY contains the row number where the first row of + // the current line is 0. + cursorX, cursorY int + // maxLine is the greatest value of cursorY so far. + maxLine int + + termWidth, termHeight int + + // outBuf contains the terminal data to be sent. + outBuf []byte + // remainder contains the remainder of any partial key sequences after + // a read. It aliases into inBuf. + remainder []byte + inBuf [256]byte + + // history contains previously entered commands so that they can be + // accessed with the up and down keys. + history stRingBuffer + // historyIndex stores the currently accessed history entry, where zero + // means the immediately previous entry. + historyIndex int + // When navigating up and down the history it's possible to return to + // the incomplete, initial line. That value is stored in + // historyPending. + historyPending string +} + +// NewTerminal runs a VT100 terminal on the given ReadWriter. If the ReadWriter is +// a local terminal, that terminal must first have been put into raw mode. +// prompt is a string that is written at the start of each input line (i.e. +// "> "). +func NewTerminal(c io.ReadWriter, prompt string) *Terminal { + return &Terminal{ + Escape: &vt100EscapeCodes, + c: c, + prompt: []rune(prompt), + termWidth: 80, + termHeight: 24, + echo: true, + historyIndex: -1, + } +} + +const ( + keyCtrlD = 4 + keyCtrlU = 21 + keyEnter = '\r' + keyEscape = 27 + keyBackspace = 127 + keyUnknown = 0xd800 /* UTF-16 surrogate area */ + iota + keyUp + keyDown + keyLeft + keyRight + keyAltLeft + keyAltRight + keyHome + keyEnd + keyDeleteWord + keyDeleteLine + keyClearScreen + keyPasteStart + keyPasteEnd +) + +var ( + crlf = []byte{'\r', '\n'} + pasteStart = []byte{keyEscape, '[', '2', '0', '0', '~'} + pasteEnd = []byte{keyEscape, '[', '2', '0', '1', '~'} +) + +// bytesToKey tries to parse a key sequence from b. If successful, it returns +// the key and the remainder of the input. Otherwise it returns utf8.RuneError. +func bytesToKey(b []byte, pasteActive bool) (rune, []byte) { + if len(b) == 0 { + return utf8.RuneError, nil + } + + if !pasteActive { + switch b[0] { + case 1: // ^A + return keyHome, b[1:] + case 5: // ^E + return keyEnd, b[1:] + case 8: // ^H + return keyBackspace, b[1:] + case 11: // ^K + return keyDeleteLine, b[1:] + case 12: // ^L + return keyClearScreen, b[1:] + case 23: // ^W + return keyDeleteWord, b[1:] + } + } + + if b[0] != keyEscape { + if !utf8.FullRune(b) { + return utf8.RuneError, b + } + r, l := utf8.DecodeRune(b) + return r, b[l:] + } + + if !pasteActive && len(b) >= 3 && b[0] == keyEscape && b[1] == '[' { + switch b[2] { + case 'A': + return keyUp, b[3:] + case 'B': + return keyDown, b[3:] + case 'C': + return keyRight, b[3:] + case 'D': + return keyLeft, b[3:] + case 'H': + return keyHome, b[3:] + case 'F': + return keyEnd, b[3:] + } + } + + if !pasteActive && len(b) >= 6 && b[0] == keyEscape && b[1] == '[' && b[2] == '1' && b[3] == ';' && b[4] == '3' { + switch b[5] { + case 'C': + return keyAltRight, b[6:] + case 'D': + return keyAltLeft, b[6:] + } + } + + if !pasteActive && len(b) >= 6 && bytes.Equal(b[:6], pasteStart) { + return keyPasteStart, b[6:] + } + + if pasteActive && len(b) >= 6 && bytes.Equal(b[:6], pasteEnd) { + return keyPasteEnd, b[6:] + } + + // If we get here then we have a key that we don't recognise, or a + // partial sequence. It's not clear how one should find the end of a + // sequence without knowing them all, but it seems that [a-zA-Z~] only + // appears at the end of a sequence. + for i, c := range b[0:] { + if c >= 'a' && c <= 'z' || c >= 'A' && c <= 'Z' || c == '~' { + return keyUnknown, b[i+1:] + } + } + + return utf8.RuneError, b +} + +// queue appends data to the end of t.outBuf +func (t *Terminal) queue(data []rune) { + t.outBuf = append(t.outBuf, []byte(string(data))...) +} + +var eraseUnderCursor = []rune{' ', keyEscape, '[', 'D'} +var space = []rune{' '} + +func isPrintable(key rune) bool { + isInSurrogateArea := key >= 0xd800 && key <= 0xdbff + return key >= 32 && !isInSurrogateArea +} + +// moveCursorToPos appends data to t.outBuf which will move the cursor to the +// given, logical position in the text. +func (t *Terminal) moveCursorToPos(pos int) { + if !t.echo { + return + } + + x := visualLength(t.prompt) + pos + y := x / t.termWidth + x = x % t.termWidth + + up := 0 + if y < t.cursorY { + up = t.cursorY - y + } + + down := 0 + if y > t.cursorY { + down = y - t.cursorY + } + + left := 0 + if x < t.cursorX { + left = t.cursorX - x + } + + right := 0 + if x > t.cursorX { + right = x - t.cursorX + } + + t.cursorX = x + t.cursorY = y + t.move(up, down, left, right) +} + +func (t *Terminal) move(up, down, left, right int) { + movement := make([]rune, 3*(up+down+left+right)) + m := movement + for i := 0; i < up; i++ { + m[0] = keyEscape + m[1] = '[' + m[2] = 'A' + m = m[3:] + } + for i := 0; i < down; i++ { + m[0] = keyEscape + m[1] = '[' + m[2] = 'B' + m = m[3:] + } + for i := 0; i < left; i++ { + m[0] = keyEscape + m[1] = '[' + m[2] = 'D' + m = m[3:] + } + for i := 0; i < right; i++ { + m[0] = keyEscape + m[1] = '[' + m[2] = 'C' + m = m[3:] + } + + t.queue(movement) +} + +func (t *Terminal) clearLineToRight() { + op := []rune{keyEscape, '[', 'K'} + t.queue(op) +} + +const maxLineLength = 4096 + +func (t *Terminal) setLine(newLine []rune, newPos int) { + if t.echo { + t.moveCursorToPos(0) + t.writeLine(newLine) + for i := len(newLine); i < len(t.line); i++ { + t.writeLine(space) + } + t.moveCursorToPos(newPos) + } + t.line = newLine + t.pos = newPos +} + +func (t *Terminal) advanceCursor(places int) { + t.cursorX += places + t.cursorY += t.cursorX / t.termWidth + if t.cursorY > t.maxLine { + t.maxLine = t.cursorY + } + t.cursorX = t.cursorX % t.termWidth + + if places > 0 && t.cursorX == 0 { + // Normally terminals will advance the current position + // when writing a character. But that doesn't happen + // for the last character in a line. However, when + // writing a character (except a new line) that causes + // a line wrap, the position will be advanced two + // places. + // + // So, if we are stopping at the end of a line, we + // need to write a newline so that our cursor can be + // advanced to the next line. + t.outBuf = append(t.outBuf, '\r', '\n') + } +} + +func (t *Terminal) eraseNPreviousChars(n int) { + if n == 0 { + return + } + + if t.pos < n { + n = t.pos + } + t.pos -= n + t.moveCursorToPos(t.pos) + + copy(t.line[t.pos:], t.line[n+t.pos:]) + t.line = t.line[:len(t.line)-n] + if t.echo { + t.writeLine(t.line[t.pos:]) + for i := 0; i < n; i++ { + t.queue(space) + } + t.advanceCursor(n) + t.moveCursorToPos(t.pos) + } +} + +// countToLeftWord returns then number of characters from the cursor to the +// start of the previous word. +func (t *Terminal) countToLeftWord() int { + if t.pos == 0 { + return 0 + } + + pos := t.pos - 1 + for pos > 0 { + if t.line[pos] != ' ' { + break + } + pos-- + } + for pos > 0 { + if t.line[pos] == ' ' { + pos++ + break + } + pos-- + } + + return t.pos - pos +} + +// countToRightWord returns then number of characters from the cursor to the +// start of the next word. +func (t *Terminal) countToRightWord() int { + pos := t.pos + for pos < len(t.line) { + if t.line[pos] == ' ' { + break + } + pos++ + } + for pos < len(t.line) { + if t.line[pos] != ' ' { + break + } + pos++ + } + return pos - t.pos +} + +// visualLength returns the number of visible glyphs in s. +func visualLength(runes []rune) int { + inEscapeSeq := false + length := 0 + + for _, r := range runes { + switch { + case inEscapeSeq: + if (r >= 'a' && r <= 'z') || (r >= 'A' && r <= 'Z') { + inEscapeSeq = false + } + case r == '\x1b': + inEscapeSeq = true + default: + length++ + } + } + + return length +} + +// handleKey processes the given key and, optionally, returns a line of text +// that the user has entered. +func (t *Terminal) handleKey(key rune) (line string, ok bool) { + if t.pasteActive && key != keyEnter { + t.addKeyToLine(key) + return + } + + switch key { + case keyBackspace: + if t.pos == 0 { + return + } + t.eraseNPreviousChars(1) + case keyAltLeft: + // move left by a word. + t.pos -= t.countToLeftWord() + t.moveCursorToPos(t.pos) + case keyAltRight: + // move right by a word. + t.pos += t.countToRightWord() + t.moveCursorToPos(t.pos) + case keyLeft: + if t.pos == 0 { + return + } + t.pos-- + t.moveCursorToPos(t.pos) + case keyRight: + if t.pos == len(t.line) { + return + } + t.pos++ + t.moveCursorToPos(t.pos) + case keyHome: + if t.pos == 0 { + return + } + t.pos = 0 + t.moveCursorToPos(t.pos) + case keyEnd: + if t.pos == len(t.line) { + return + } + t.pos = len(t.line) + t.moveCursorToPos(t.pos) + case keyUp: + entry, ok := t.history.NthPreviousEntry(t.historyIndex + 1) + if !ok { + return "", false + } + if t.historyIndex == -1 { + t.historyPending = string(t.line) + } + t.historyIndex++ + runes := []rune(entry) + t.setLine(runes, len(runes)) + case keyDown: + switch t.historyIndex { + case -1: + return + case 0: + runes := []rune(t.historyPending) + t.setLine(runes, len(runes)) + t.historyIndex-- + default: + entry, ok := t.history.NthPreviousEntry(t.historyIndex - 1) + if ok { + t.historyIndex-- + runes := []rune(entry) + t.setLine(runes, len(runes)) + } + } + case keyEnter: + t.moveCursorToPos(len(t.line)) + t.queue([]rune("\r\n")) + line = string(t.line) + ok = true + t.line = t.line[:0] + t.pos = 0 + t.cursorX = 0 + t.cursorY = 0 + t.maxLine = 0 + case keyDeleteWord: + // Delete zero or more spaces and then one or more characters. + t.eraseNPreviousChars(t.countToLeftWord()) + case keyDeleteLine: + // Delete everything from the current cursor position to the + // end of line. + for i := t.pos; i < len(t.line); i++ { + t.queue(space) + t.advanceCursor(1) + } + t.line = t.line[:t.pos] + t.moveCursorToPos(t.pos) + case keyCtrlD: + // Erase the character under the current position. + // The EOF case when the line is empty is handled in + // readLine(). + if t.pos < len(t.line) { + t.pos++ + t.eraseNPreviousChars(1) + } + case keyCtrlU: + t.eraseNPreviousChars(t.pos) + case keyClearScreen: + // Erases the screen and moves the cursor to the home position. + t.queue([]rune("\x1b[2J\x1b[H")) + t.queue(t.prompt) + t.cursorX, t.cursorY = 0, 0 + t.advanceCursor(visualLength(t.prompt)) + t.setLine(t.line, t.pos) + default: + if t.AutoCompleteCallback != nil { + prefix := string(t.line[:t.pos]) + suffix := string(t.line[t.pos:]) + + t.lock.Unlock() + newLine, newPos, completeOk := t.AutoCompleteCallback(prefix+suffix, len(prefix), key) + t.lock.Lock() + + if completeOk { + t.setLine([]rune(newLine), utf8.RuneCount([]byte(newLine)[:newPos])) + return + } + } + if !isPrintable(key) { + return + } + if len(t.line) == maxLineLength { + return + } + t.addKeyToLine(key) + } + return +} + +// addKeyToLine inserts the given key at the current position in the current +// line. +func (t *Terminal) addKeyToLine(key rune) { + if len(t.line) == cap(t.line) { + newLine := make([]rune, len(t.line), 2*(1+len(t.line))) + copy(newLine, t.line) + t.line = newLine + } + t.line = t.line[:len(t.line)+1] + copy(t.line[t.pos+1:], t.line[t.pos:]) + t.line[t.pos] = key + if t.echo { + t.writeLine(t.line[t.pos:]) + } + t.pos++ + t.moveCursorToPos(t.pos) +} + +func (t *Terminal) writeLine(line []rune) { + for len(line) != 0 { + remainingOnLine := t.termWidth - t.cursorX + todo := len(line) + if todo > remainingOnLine { + todo = remainingOnLine + } + t.queue(line[:todo]) + t.advanceCursor(visualLength(line[:todo])) + line = line[todo:] + } +} + +// writeWithCRLF writes buf to w but replaces all occurrences of \n with \r\n. +func writeWithCRLF(w io.Writer, buf []byte) (n int, err error) { + for len(buf) > 0 { + i := bytes.IndexByte(buf, '\n') + todo := len(buf) + if i >= 0 { + todo = i + } + + var nn int + nn, err = w.Write(buf[:todo]) + n += nn + if err != nil { + return n, err + } + buf = buf[todo:] + + if i >= 0 { + if _, err = w.Write(crlf); err != nil { + return n, err + } + n += 1 + buf = buf[1:] + } + } + + return n, nil +} + +func (t *Terminal) Write(buf []byte) (n int, err error) { + t.lock.Lock() + defer t.lock.Unlock() + + if t.cursorX == 0 && t.cursorY == 0 { + // This is the easy case: there's nothing on the screen that we + // have to move out of the way. + return writeWithCRLF(t.c, buf) + } + + // We have a prompt and possibly user input on the screen. We + // have to clear it first. + t.move(0 /* up */, 0 /* down */, t.cursorX /* left */, 0 /* right */) + t.cursorX = 0 + t.clearLineToRight() + + for t.cursorY > 0 { + t.move(1 /* up */, 0, 0, 0) + t.cursorY-- + t.clearLineToRight() + } + + if _, err = t.c.Write(t.outBuf); err != nil { + return + } + t.outBuf = t.outBuf[:0] + + if n, err = writeWithCRLF(t.c, buf); err != nil { + return + } + + t.writeLine(t.prompt) + if t.echo { + t.writeLine(t.line) + } + + t.moveCursorToPos(t.pos) + + if _, err = t.c.Write(t.outBuf); err != nil { + return + } + t.outBuf = t.outBuf[:0] + return +} + +// ReadPassword temporarily changes the prompt and reads a password, without +// echo, from the terminal. +func (t *Terminal) ReadPassword(prompt string) (line string, err error) { + t.lock.Lock() + defer t.lock.Unlock() + + oldPrompt := t.prompt + t.prompt = []rune(prompt) + t.echo = false + + line, err = t.readLine() + + t.prompt = oldPrompt + t.echo = true + + return +} + +// ReadLine returns a line of input from the terminal. +func (t *Terminal) ReadLine() (line string, err error) { + t.lock.Lock() + defer t.lock.Unlock() + + return t.readLine() +} + +func (t *Terminal) readLine() (line string, err error) { + // t.lock must be held at this point + + if t.cursorX == 0 && t.cursorY == 0 { + t.writeLine(t.prompt) + t.c.Write(t.outBuf) + t.outBuf = t.outBuf[:0] + } + + lineIsPasted := t.pasteActive + + for { + rest := t.remainder + lineOk := false + for !lineOk { + var key rune + key, rest = bytesToKey(rest, t.pasteActive) + if key == utf8.RuneError { + break + } + if !t.pasteActive { + if key == keyCtrlD { + if len(t.line) == 0 { + return "", io.EOF + } + } + if key == keyPasteStart { + t.pasteActive = true + if len(t.line) == 0 { + lineIsPasted = true + } + continue + } + } else if key == keyPasteEnd { + t.pasteActive = false + continue + } + if !t.pasteActive { + lineIsPasted = false + } + line, lineOk = t.handleKey(key) + } + if len(rest) > 0 { + n := copy(t.inBuf[:], rest) + t.remainder = t.inBuf[:n] + } else { + t.remainder = nil + } + t.c.Write(t.outBuf) + t.outBuf = t.outBuf[:0] + if lineOk { + if t.echo { + t.historyIndex = -1 + t.history.Add(line) + } + if lineIsPasted { + err = ErrPasteIndicator + } + return + } + + // t.remainder is a slice at the beginning of t.inBuf + // containing a partial key sequence + readBuf := t.inBuf[len(t.remainder):] + var n int + + t.lock.Unlock() + n, err = t.c.Read(readBuf) + t.lock.Lock() + + if err != nil { + return + } + + t.remainder = t.inBuf[:n+len(t.remainder)] + } +} + +// SetPrompt sets the prompt to be used when reading subsequent lines. +func (t *Terminal) SetPrompt(prompt string) { + t.lock.Lock() + defer t.lock.Unlock() + + t.prompt = []rune(prompt) +} + +func (t *Terminal) clearAndRepaintLinePlusNPrevious(numPrevLines int) { + // Move cursor to column zero at the start of the line. + t.move(t.cursorY, 0, t.cursorX, 0) + t.cursorX, t.cursorY = 0, 0 + t.clearLineToRight() + for t.cursorY < numPrevLines { + // Move down a line + t.move(0, 1, 0, 0) + t.cursorY++ + t.clearLineToRight() + } + // Move back to beginning. + t.move(t.cursorY, 0, 0, 0) + t.cursorX, t.cursorY = 0, 0 + + t.queue(t.prompt) + t.advanceCursor(visualLength(t.prompt)) + t.writeLine(t.line) + t.moveCursorToPos(t.pos) +} + +func (t *Terminal) SetSize(width, height int) error { + t.lock.Lock() + defer t.lock.Unlock() + + if width == 0 { + width = 1 + } + + oldWidth := t.termWidth + t.termWidth, t.termHeight = width, height + + switch { + case width == oldWidth: + // If the width didn't change then nothing else needs to be + // done. + return nil + case len(t.line) == 0 && t.cursorX == 0 && t.cursorY == 0: + // If there is nothing on current line and no prompt printed, + // just do nothing + return nil + case width < oldWidth: + // Some terminals (e.g. xterm) will truncate lines that were + // too long when shinking. Others, (e.g. gnome-terminal) will + // attempt to wrap them. For the former, repainting t.maxLine + // works great, but that behaviour goes badly wrong in the case + // of the latter because they have doubled every full line. + + // We assume that we are working on a terminal that wraps lines + // and adjust the cursor position based on every previous line + // wrapping and turning into two. This causes the prompt on + // xterms to move upwards, which isn't great, but it avoids a + // huge mess with gnome-terminal. + if t.cursorX >= t.termWidth { + t.cursorX = t.termWidth - 1 + } + t.cursorY *= 2 + t.clearAndRepaintLinePlusNPrevious(t.maxLine * 2) + case width > oldWidth: + // If the terminal expands then our position calculations will + // be wrong in the future because we think the cursor is + // |t.pos| chars into the string, but there will be a gap at + // the end of any wrapped line. + // + // But the position will actually be correct until we move, so + // we can move back to the beginning and repaint everything. + t.clearAndRepaintLinePlusNPrevious(t.maxLine) + } + + _, err := t.c.Write(t.outBuf) + t.outBuf = t.outBuf[:0] + return err +} + +type pasteIndicatorError struct{} + +func (pasteIndicatorError) Error() string { + return "terminal: ErrPasteIndicator not correctly handled" +} + +// ErrPasteIndicator may be returned from ReadLine as the error, in addition +// to valid line data. It indicates that bracketed paste mode is enabled and +// that the returned line consists only of pasted data. Programs may wish to +// interpret pasted data more literally than typed data. +var ErrPasteIndicator = pasteIndicatorError{} + +// SetBracketedPasteMode requests that the terminal bracket paste operations +// with markers. Not all terminals support this but, if it is supported, then +// enabling this mode will stop any autocomplete callback from running due to +// pastes. Additionally, any lines that are completely pasted will be returned +// from ReadLine with the error set to ErrPasteIndicator. +func (t *Terminal) SetBracketedPasteMode(on bool) { + if on { + io.WriteString(t.c, "\x1b[?2004h") + } else { + io.WriteString(t.c, "\x1b[?2004l") + } +} + +// stRingBuffer is a ring buffer of strings. +type stRingBuffer struct { + // entries contains max elements. + entries []string + max int + // head contains the index of the element most recently added to the ring. + head int + // size contains the number of elements in the ring. + size int +} + +func (s *stRingBuffer) Add(a string) { + if s.entries == nil { + const defaultNumEntries = 100 + s.entries = make([]string, defaultNumEntries) + s.max = defaultNumEntries + } + + s.head = (s.head + 1) % s.max + s.entries[s.head] = a + if s.size < s.max { + s.size++ + } +} + +// NthPreviousEntry returns the value passed to the nth previous call to Add. +// If n is zero then the immediately prior value is returned, if one, then the +// next most recent, and so on. If such an element doesn't exist then ok is +// false. +func (s *stRingBuffer) NthPreviousEntry(n int) (value string, ok bool) { + if n >= s.size { + return "", false + } + index := s.head - n + if index < 0 { + index += s.max + } + return s.entries[index], true +} + +// readPasswordLine reads from reader until it finds \n or io.EOF. +// The slice returned does not include the \n. +// readPasswordLine also ignores any \r it finds. +func readPasswordLine(reader io.Reader) ([]byte, error) { + var buf [1]byte + var ret []byte + + for { + n, err := reader.Read(buf[:]) + if n > 0 { + switch buf[0] { + case '\n': + return ret, nil + case '\r': + // remove \r from passwords on Windows + default: + ret = append(ret, buf[0]) + } + continue + } + if err != nil { + if err == io.EOF && len(ret) > 0 { + return ret, nil + } + return ret, err + } + } +} |