-
Notifications
You must be signed in to change notification settings - Fork 3
/
dos2unix.go
132 lines (103 loc) · 1.88 KB
/
dos2unix.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
// Package dos2unix provides functions to convert between dos and unix line
// termination styles.
package dos2unix // import "vimagination.zapto.org/dos2unix"
import (
"io"
"slices"
)
type byteReader struct {
io.Reader
buf [1]byte
}
func (b *byteReader) ReadByte() (byte, error) {
_, err := io.ReadFull(b.Reader, b.buf[:])
return b.buf[0], err
}
type dos2unix struct {
r io.Reader
b bool
char [1]byte
}
func (d *dos2unix) Read(b []byte) (int, error) {
if len(b) == 0 {
return 0, nil
}
var n int
s := b
if d.b {
b[0] = d.char[0]
s = b[1:]
n = 1
if d.b = len(s) == 0 && b[0] == '\r'; d.b {
_, err := d.r.Read(d.char[:])
if d.char[0] == '\n' {
b[0] = '\n'
d.b = false
}
return n, err
}
}
m, err := d.r.Read(s)
n += m
lastIsCR := false
for i := 0; i < n; i++ {
c := b[i]
if lastIsCR && c == '\n' {
b = slices.Delete(b, i-1, i)
n--
i--
}
lastIsCR = c == '\r'
}
if lastIsCR && err == nil {
n--
d.char[0] = '\r'
}
d.b = lastIsCR
return n, err
}
// DOS2Unix wraps a byte reader with a reader that replaces all instances of
// \r\n with \n.
func DOS2Unix(r io.Reader) io.Reader {
return &dos2unix{r: r}
}
type unix2dos struct {
r io.ByteReader
lf bool
}
func (u *unix2dos) Read(b []byte) (int, error) {
var n int
for len(b) > 0 {
if u.lf {
b[0] = '\n'
u.lf = false
b = b[1:]
n++
continue
}
c, err := u.r.ReadByte()
if err != nil {
return n, err
}
if c == '\n' {
u.lf = true
c = '\r'
}
b[0] = c
b = b[1:]
n++
}
return n, nil
}
// Unix2DOS wraps a byte reader with a reader that replaces all instances of \n
// with \r\n.
//
// When reading from a non-buffered input, it is recommended to wrap the Reader
// with a bufio.Reader.
func Unix2DOS(r io.Reader) io.Reader {
br, ok := r.(io.ByteReader)
if !ok {
br = &byteReader{Reader: r}
}
return &unix2dos{r: br}
}