forked from deis/deis
-
Notifications
You must be signed in to change notification settings - Fork 0
/
gexpect.go
277 lines (237 loc) · 5.16 KB
/
gexpect.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
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
package gexpect
import (
"errors"
shell "github.com/kballard/go-shellquote"
"github.com/kr/pty"
"io"
"os"
"os/exec"
"regexp"
"time"
)
type ExpectSubprocess struct {
Cmd *exec.Cmd
f *os.File
}
func SpawnAtDirectory(command string, directory string) (*ExpectSubprocess, error) {
expect, err := _spawn(command)
if err != nil {
return nil, err
}
expect.Cmd.Dir = directory
return _start(expect)
}
func Command(command string) (*ExpectSubprocess, error) {
expect, err := _spawn(command)
if err != nil {
return nil, err
}
return expect, nil
}
func (expect *ExpectSubprocess) Start() error {
_, err := _start(expect)
return err
}
func Spawn(command string) (*ExpectSubprocess, error) {
expect, err := _spawn(command)
if err != nil {
return nil, err
}
return _start(expect)
}
func (expect *ExpectSubprocess) Close() error {
return expect.Cmd.Process.Kill()
}
func (expect *ExpectSubprocess) AsyncInteractChannels() (send chan string, receive chan string) {
receive = make(chan string)
send = make(chan string)
go func() {
for {
str, err := expect.ReadLine()
if err != nil {
close(receive)
return
}
receive <- str
}
}()
go func() {
for {
select {
case sendCommand, exists := <-send:
{
if !exists {
return
}
err := expect.Send(sendCommand)
if err != nil {
receive <- "gexpect Error: " + err.Error()
return
}
}
}
}
}()
return
}
// This quite possibly won't work as we're operating on an incomplete stream. It might work if all the input is within one
// Flush, but that can't be relied upon. I need to find a nice, safe way to apply a regex to a stream of partial content, given we
// don't not knowing how long our input is, and thus can't buffer it. Until that point, please just use Expect, or use the channel
// to parse the stream yourself.
func (expect *ExpectSubprocess) ExpectRegex(regexSearchString string) (e error) {
var size = len(regexSearchString)
if size < 255 {
size = 255
}
chunk := make([]byte, size)
for {
n, err := expect.f.Read(chunk)
if err != nil {
return err
}
success, err := regexp.Match(regexSearchString, chunk[:n])
if err != nil {
return err
}
if success {
return nil
}
}
}
func buildKMPTable(searchString string) []int {
pos := 2
cnd := 0
length := len(searchString)
var table []int
if length < 2 {
length = 2
}
table = make([]int, length)
table[0] = -1
table[1] = 0
for pos < len(searchString) {
if searchString[pos-1] == searchString[cnd] {
cnd += 1
table[pos] = cnd
pos += 1
} else if cnd > 0 {
cnd = table[cnd]
} else {
table[pos] = 0
pos += 1
}
}
return table
}
func (expect *ExpectSubprocess) ExpectTimeout(searchString string, timeout time.Duration) (e error) {
result := make(chan error)
go func() {
result <- expect.Expect(searchString)
}()
select {
case e = <-result:
case <-time.After(timeout):
e = errors.New("Expect timed out.")
}
return e
}
func (expect *ExpectSubprocess) Expect(searchString string) (e error) {
chunk := make([]byte, len(searchString)*2)
target := len(searchString)
m := 0
i := 0
// Build KMP Table
table := buildKMPTable(searchString)
for {
n, err := expect.f.Read(chunk)
if err != nil {
return err
}
offset := m + i
for m+i-offset < n {
if searchString[i] == chunk[m+i-offset] {
i += 1
if i == target {
return nil
}
} else {
m += i - table[i]
if table[i] > -1 {
i = table[i]
} else {
i = 0
}
}
}
}
}
func (expect *ExpectSubprocess) Send(command string) error {
_, err := io.WriteString(expect.f, command)
return err
}
func (expect *ExpectSubprocess) SendLine(command string) error {
_, err := io.WriteString(expect.f, command+"\r\n")
return err
}
func (expect *ExpectSubprocess) Interact() {
defer expect.Cmd.Wait()
go io.Copy(os.Stdout, expect.f)
go io.Copy(os.Stderr, expect.f)
go io.Copy(expect.f, os.Stdin)
}
func (expect *ExpectSubprocess) ReadUntil(delim byte) ([]byte, error) {
join := make([]byte, 1, 512)
chunk := make([]byte, 255)
for {
n, err := expect.f.Read(chunk)
if err != nil {
return join, err
}
for i := 0; i < n; i++ {
if chunk[i] == delim {
return join, nil
} else {
join = append(join, chunk[i])
}
}
}
}
func (expect *ExpectSubprocess) Wait() error {
return expect.Cmd.Wait()
}
func (expect *ExpectSubprocess) ReadLine() (string, error) {
str, err := expect.ReadUntil('\n')
if err != nil {
return "", err
}
return string(str), nil
}
func _start(expect *ExpectSubprocess) (*ExpectSubprocess, error) {
f, err := pty.Start(expect.Cmd)
if err != nil {
return nil, err
}
expect.f = f
return expect, nil
}
func _spawn(command string) (*ExpectSubprocess, error) {
wrapper := new(ExpectSubprocess)
splitArgs, err := shell.Split(command)
if err != nil {
return nil, err
}
numArguments := len(splitArgs) - 1
if numArguments < 0 {
return nil, errors.New("gexpect: No command given to spawn")
}
path, err := exec.LookPath(splitArgs[0])
if err != nil {
return nil, err
}
if numArguments >= 1 {
wrapper.Cmd = exec.Command(path, splitArgs[1:]...)
} else {
wrapper.Cmd = exec.Command(path)
}
return wrapper, nil
}