go.crypto/ssh/terminal: handle ^W, ^K and ^H
R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/13207043
diff --git a/terminal.go b/terminal.go
index 411b1f1..bb69c5b 100644
--- a/terminal.go
+++ b/terminal.go
@@ -118,6 +118,8 @@
keyAltRight
keyHome
keyEnd
+ keyDeleteWord
+ keyDeleteLine
)
// bytesToKey tries to parse a key sequence from b. If successful, it returns
@@ -127,6 +129,15 @@
return -1, nil
}
+ switch b[0] {
+ case 8: // ^H
+ return keyBackspace, b[1:]
+ case 11: // ^K
+ return keyDeleteLine, b[1:]
+ case 23: // ^W
+ return keyDeleteWord, b[1:]
+ }
+
if b[0] != keyEscape {
return int(b[0]), b[1:]
}
@@ -274,6 +285,73 @@
t.pos = newPos
}
+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.cursorX += 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
+}
+
// handleKey processes the given key and, optionally, returns a line of text
// that the user has entered.
func (t *Terminal) handleKey(key int) (line string, ok bool) {
@@ -282,50 +360,14 @@
if t.pos == 0 {
return
}
- t.pos--
- t.moveCursorToPos(t.pos)
-
- copy(t.line[t.pos:], t.line[1+t.pos:])
- t.line = t.line[:len(t.line)-1]
- if t.echo {
- t.writeLine(t.line[t.pos:])
- }
- t.queue(eraseUnderCursor)
- t.moveCursorToPos(t.pos)
+ t.eraseNPreviousChars(1)
case keyAltLeft:
// move left by a word.
- if t.pos == 0 {
- return
- }
- t.pos--
- for t.pos > 0 {
- if t.line[t.pos] != ' ' {
- break
- }
- t.pos--
- }
- for t.pos > 0 {
- if t.line[t.pos] == ' ' {
- t.pos++
- break
- }
- t.pos--
- }
+ t.pos -= t.countToLeftWord()
t.moveCursorToPos(t.pos)
case keyAltRight:
// move right by a word.
- for t.pos < len(t.line) {
- if t.line[t.pos] == ' ' {
- break
- }
- t.pos++
- }
- for t.pos < len(t.line) {
- if t.line[t.pos] != ' ' {
- break
- }
- t.pos++
- }
+ t.pos += t.countToRightWord()
t.moveCursorToPos(t.pos)
case keyLeft:
if t.pos == 0 {
@@ -385,6 +427,18 @@
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.cursorX++
+ }
+ t.line = t.line[:t.pos]
+ t.moveCursorToPos(t.pos)
default:
if t.AutoCompleteCallback != nil {
t.lock.Unlock()
diff --git a/terminal_test.go b/terminal_test.go
index 7db3171..75584d3 100644
--- a/terminal_test.go
+++ b/terminal_test.go
@@ -101,11 +101,47 @@
line: "line1xxx",
throwAwayLines: 2,
},
+ {
+ in: "\027\r",
+ line: "",
+ },
+ {
+ in: "a\027\r",
+ line: "",
+ },
+ {
+ in: "a \027\r",
+ line: "",
+ },
+ {
+ in: "a b\027\r",
+ line: "a ",
+ },
+ {
+ in: "a b \027\r",
+ line: "a ",
+ },
+ {
+ in: "one two thr\x1b[D\027\r",
+ line: "one two r",
+ },
+ {
+ in: "\013\r",
+ line: "",
+ },
+ {
+ in: "a\013\r",
+ line: "a",
+ },
+ {
+ in: "ab\x1b[D\013\r",
+ line: "a",
+ },
}
func TestKeyPresses(t *testing.T) {
for i, test := range keyPressTests {
- for j := 0; j < len(test.in); j++ {
+ for j := 1; j < len(test.in); j++ {
c := &MockTerminal{
toSend: []byte(test.in),
bytesPerRead: j,
