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
|
package cwriter
import (
"bytes"
"errors"
"io"
"os"
"strconv"
)
// https://github.com/dylanaraps/pure-sh-bible#cursor-movement
const (
escOpen = "\x1b["
cuuAndEd = "A\x1b[J"
)
// ErrNotTTY not a TeleTYpewriter error.
var ErrNotTTY = errors.New("not a terminal")
// New returns a new Writer with defaults.
func New(out io.Writer) *Writer {
w := &Writer{
Buffer: new(bytes.Buffer),
out: out,
termSize: func(_ int) (int, int, error) {
return -1, -1, ErrNotTTY
},
}
if f, ok := out.(*os.File); ok {
w.fd = int(f.Fd())
if IsTerminal(w.fd) {
w.terminal = true
w.termSize = func(fd int) (int, int, error) {
return GetSize(fd)
}
}
}
bb := make([]byte, 16)
w.ew = escWriter(bb[:copy(bb, []byte(escOpen))])
return w
}
// IsTerminal tells whether underlying io.Writer is terminal.
func (w *Writer) IsTerminal() bool {
return w.terminal
}
// GetTermSize returns WxH of underlying terminal.
func (w *Writer) GetTermSize() (width, height int, err error) {
return w.termSize(w.fd)
}
type escWriter []byte
func (b escWriter) ansiCuuAndEd(out io.Writer, n int) error {
b = strconv.AppendInt(b, int64(n), 10)
_, err := out.Write(append(b, []byte(cuuAndEd)...))
return err
}
|
