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
|
/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) Manuel Novoa III <mjn3@codepoet.org>
* and Vladimir Oleynik <dzo@simtreas.ru>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
#define WANT_HEX_ESCAPES 1
/* Usual "this only works for ascii compatible encodings" disclaimer. */
#undef _tolower
#define _tolower(X) ((X)|((char) 0x20))
char FAST_FUNC bb_process_escape_sequence(const char **ptr)
{
/* bash builtin "echo -e '\ec'" interprets \e as ESC,
* but coreutils "/bin/echo -e '\ec'" does not.
* manpages tend to support coreutils way.
* Update: coreutils added support for \e on 28 Oct 2009. */
static const char charmap[] ALIGN1 = {
'a', 'b', 'e', 'f', 'n', 'r', 't', 'v', '\\', 0,
'\a', '\b', 27, '\f', '\n', '\r', '\t', '\v', '\\', '\\' };
const char *p;
const char *q;
unsigned num_digits;
unsigned r;
unsigned n;
unsigned base;
num_digits = n = 0;
base = 8;
q = *ptr;
#if WANT_HEX_ESCAPES
if (*q == 'x') {
++q;
base = 16;
++num_digits;
}
#endif
/* bash requires leading 0 in octal escapes:
* \02 works, \2 does not (prints \ and 2).
* We treat \2 as a valid octal escape sequence. */
do {
#if !WANT_HEX_ESCAPES
unsigned d = (unsigned char)(*q) - '0';
#else
unsigned d = (unsigned char)_tolower(*q) - '0';
if (d >= 10)
d += ('0' - 'a' + 10);
#endif
if (d >= base) {
if (WANT_HEX_ESCAPES && base == 16) {
--num_digits;
if (num_digits == 0) {
/* \x<bad_char> */
--q; /* go back to x */
}
}
break;
}
r = n * base + d;
if (r > UCHAR_MAX) {
break;
}
n = r;
++q;
} while (++num_digits < 3);
if (num_digits == 0) { /* mnemonic escape sequence? */
p = charmap;
do {
if (*p == *q) {
q++;
break;
}
} while (*++p);
/* p points to found escape char or NUL,
* advance it and find what it translates to.
* Note that unrecognized sequence \z returns '\'
* and leaves ptr pointing to z. */
p += sizeof(charmap) / 2;
n = *p;
}
*ptr = q;
return (char) n;
}
char* FAST_FUNC strcpy_and_process_escape_sequences(char *dst, const char *src)
{
while (1) {
char c, c1;
c = c1 = *src++;
if (c1 == '\\')
c1 = bb_process_escape_sequence(&src);
*dst = c1;
if (c == '\0')
return dst;
dst++;
}
}
|
