/
watch.go
131 lines (107 loc) · 2.09 KB
/
watch.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
package async_script
import (
"bufio"
"fmt"
"io"
"os"
"strings"
"golang.org/x/crypto/ssh/terminal"
)
const ttyClearAfterCursor = "\u001b[0J"
const ttyCursorUp = "\u001b[%vA"
type WatchAsyncPipe struct {
in io.ReadCloser
pipeR *os.File
pipeW *os.File
buf []string
bufIdx int
}
func Watch(lines int) Op {
return &WatchAsyncPipe{
os.Stdin,
nil,
nil,
make([]string, lines, lines),
0,
}
}
func (p *WatchAsyncPipe) SetInput(in io.ReadCloser) {
p.in = in
}
func (p *WatchAsyncPipe) GetReader() io.ReadCloser {
if p.pipeR != nil {
return p.pipeR
}
var err error
p.pipeR, p.pipeW, err = os.Pipe()
if err != nil {
panic(err)
}
return p.pipeR
}
func (p *WatchAsyncPipe) addBufLine(line string) {
p.buf[p.bufIdx] = line
p.bufIdx += 1
if p.bufIdx >= len(p.buf) {
p.bufIdx = 0
}
}
func (p *WatchAsyncPipe) printBufLine() {
fmt.Print(ttyClearAfterCursor)
//linesUp := 0
//terminalWidth, _, _ := terminal.GetSize(int(os.Stdout.Fd()))
for i := 0; i < len(p.buf); i++ {
idx := i + p.bufIdx
if idx >= len(p.buf) {
idx -= len(p.buf)
}
//if len(p.buf[idx]) > terminalWidth {
// linesUp += len(p.buf[idx]) / terminalWidth
//}
fmt.Println(p.buf[idx])
}
fmt.Printf(ttyCursorUp, len(p.buf))
}
func (p *WatchAsyncPipe) Run() error {
if !terminal.IsTerminal(int(os.Stdout.Fd())) && p.pipeW == nil {
p.pipeW = os.Stdout
}
var err error
c := make(chan string)
go func() {
if p.pipeW != nil && p.pipeW != os.Stdout {
defer p.pipeW.Close()
}
scanner := bufio.NewScanner(p.in)
scanner.Split(ScanLinesWithoutDrop)
for scanner.Scan() {
line := scanner.Bytes()
c <- strings.TrimRight(string(line), " \t\r\n")
if p.pipeW == nil {
continue
}
nw, ew := p.pipeW.Write(line)
if ew != nil {
err = ew
break
}
if len(line) != nw {
err = io.ErrShortWrite
break
}
}
close(c)
}()
for d := range c {
if !terminal.IsTerminal(int(os.Stdout.Fd())) {
continue
} else {
p.addBufLine(d)
p.printBufLine()
}
}
if terminal.IsTerminal(int(os.Stdout.Fd())) {
fmt.Print(ttyClearAfterCursor)
}
return err
}