-
Notifications
You must be signed in to change notification settings - Fork 3
/
term_emulator.go
234 lines (213 loc) · 6.29 KB
/
term_emulator.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
package winconsole
import (
"fmt"
"io"
"strconv"
"strings"
)
// http://manpages.ubuntu.com/manpages/intrepid/man4/console_codes.4.html
const (
ANSI_ESCAPE_PRIMARY = 0x1B
ANSI_ESCAPE_SECONDARY = 0x5B
ANSI_COMMAND_FIRST = 0x40
ANSI_COMMAND_LAST = 0x7E
ANSI_PARAMETER_SEP = ";"
ANSI_CMD_G0 = '('
ANSI_CMD_G1 = ')'
ANSI_CMD_G2 = '*'
ANSI_CMD_G3 = '+'
ANSI_CMD_DECPNM = '>'
ANSI_CMD_DECPAM = '='
ANSI_CMD_OSC = ']'
ANSI_CMD_STR_TERM = '\\'
ANSI_BEL = 0x07
KEY_EVENT = 1
)
// Interface that implements terminal handling
type terminalEmulator interface {
HandleOutputCommand(fd uintptr, command []byte) (n int, err error)
HandleInputSequence(fd uintptr, command []byte) (n int, err error)
WriteChars(fd uintptr, w io.Writer, p []byte) (n int, err error)
ReadChars(fd uintptr, w io.Reader, p []byte) (n int, err error)
}
type terminalWriter struct {
wrappedWriter io.Writer
emulator terminalEmulator
command []byte
inSequence bool
fd uintptr
}
type terminalReader struct {
wrappedReader io.ReadCloser
emulator terminalEmulator
command []byte
inSequence bool
fd uintptr
}
// http://manpages.ubuntu.com/manpages/intrepid/man4/console_codes.4.html
func isAnsiCommandChar(b byte) bool {
switch {
case ANSI_COMMAND_FIRST <= b && b <= ANSI_COMMAND_LAST && b != ANSI_ESCAPE_SECONDARY:
return true
case b == ANSI_CMD_G1 || b == ANSI_CMD_OSC || b == ANSI_CMD_DECPAM || b == ANSI_CMD_DECPNM:
// non-CSI escape sequence terminator
return true
case b == ANSI_CMD_STR_TERM || b == ANSI_BEL:
// String escape sequence terminator
return true
}
return false
}
func isCharacterSelectionCmdChar(b byte) bool {
return (b == ANSI_CMD_G0 || b == ANSI_CMD_G1 || b == ANSI_CMD_G2 || b == ANSI_CMD_G3)
}
func isXtermOscSequence(command []byte, current byte) bool {
return (len(command) >= 2 && command[0] == ANSI_ESCAPE_PRIMARY && command[1] == ANSI_CMD_OSC && current != ANSI_BEL)
}
// Write writes len(p) bytes from p to the underlying data stream.
// http://golang.org/pkg/io/#Writer
func (tw *terminalWriter) Write(p []byte) (n int, err error) {
if len(p) == 0 {
return 0, nil
}
if tw.emulator == nil {
return tw.wrappedWriter.Write(p)
}
// Emulate terminal by extracting commands and executing them
totalWritten := 0
start := 0 // indicates start of the next chunk
end := len(p)
for current := 0; current < end; current++ {
if tw.inSequence {
// inside escape sequence
tw.command = append(tw.command, p[current])
if isAnsiCommandChar(p[current]) {
if !isXtermOscSequence(tw.command, p[current]) {
// found the last command character.
// Now we have a complete command.
nchar, err := tw.emulator.HandleOutputCommand(tw.fd, tw.command)
totalWritten += nchar
if err != nil {
return totalWritten, err
}
// clear the command
// don't include current character again
tw.command = tw.command[:0]
start = current + 1
tw.inSequence = false
}
}
} else {
if p[current] == ANSI_ESCAPE_PRIMARY {
// entering escape sequnce
tw.inSequence = true
// indicates end of "normal sequence", write whatever you have so far
if len(p[start:current]) > 0 {
nw, err := tw.emulator.WriteChars(tw.fd, tw.wrappedWriter, p[start:current])
totalWritten += nw
if err != nil {
return totalWritten, err
}
}
// include the current character as part of the next sequence
tw.command = append(tw.command, p[current])
}
}
}
// note that so far, start of the escape sequence triggers writing out of bytes to console.
// For the part _after_ the end of last escape sequence, it is not written out yet. So write it out
if !tw.inSequence {
// assumption is that we can't be inside sequence and therefore command should be empty
if len(p[start:]) > 0 {
nw, err := tw.emulator.WriteChars(tw.fd, tw.wrappedWriter, p[start:])
totalWritten += nw
if err != nil {
return totalWritten, err
}
}
}
return totalWritten, nil
}
// Read reads up to len(p) bytes into p.
// http://golang.org/pkg/io/#Reader
func (tr *terminalReader) Read(p []byte) (n int, err error) {
//Implementations of Read are discouraged from returning a zero byte count
// with a nil error, except when len(p) == 0.
if len(p) == 0 {
return 0, nil
}
if nil == tr.emulator {
return tr.readFromWrappedReader(p)
}
return tr.emulator.ReadChars(tr.fd, tr.wrappedReader, p)
}
// Close the underlying stream
func (tr *terminalReader) Close() (err error) {
return tr.wrappedReader.Close()
}
func (tr *terminalReader) readFromWrappedReader(p []byte) (n int, err error) {
return tr.wrappedReader.Read(p)
}
type ansiCommand struct {
CommandBytes []byte
Command string
Parameters []string
IsSpecial bool
}
func parseAnsiCommand(command []byte) *ansiCommand {
if isCharacterSelectionCmdChar(command[1]) {
// Is Character Set Selection commands
return &ansiCommand{
CommandBytes: command,
Command: string(command),
IsSpecial: true,
}
}
// last char is command character
lastCharIndex := len(command) - 1
retValue := &ansiCommand{
CommandBytes: command,
Command: string(command[lastCharIndex]),
IsSpecial: false,
}
// more than a single escape
if lastCharIndex != 0 {
start := 1
// skip if double char escape sequence
if command[0] == ANSI_ESCAPE_PRIMARY && command[1] == ANSI_ESCAPE_SECONDARY {
start++
}
// convert this to GetNextParam method
retValue.Parameters = strings.Split(string(command[start:lastCharIndex]), ANSI_PARAMETER_SEP)
}
return retValue
}
func (c *ansiCommand) getParam(index int) string {
if len(c.Parameters) > index {
return c.Parameters[index]
}
return ""
}
func (ac *ansiCommand) String() string {
return fmt.Sprintf("0x%v \"%v\" (\"%v\")",
bytesToHex(ac.CommandBytes),
ac.Command,
strings.Join(ac.Parameters, "\",\""))
}
func bytesToHex(b []byte) string {
hex := make([]string, len(b))
for i, ch := range b {
hex[i] = fmt.Sprintf("%X", ch)
}
return strings.Join(hex, "")
}
func parseInt16OrDefault(s string, defaultValue int16) (n int16, err error) {
if s == "" {
return defaultValue, nil
}
parsedValue, err := strconv.ParseInt(s, 10, 16)
if err != nil {
return defaultValue, err
}
return int16(parsedValue), nil
}