Contents of /tags/mkinitrd-6_1_2/busybox/libbb/process_escape_sequence.c
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Mon May 4 17:23:09 2009 UTC (15 years, 4 months ago) by niro
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File size: 1636 byte(s)
Mon May 4 17:23:09 2009 UTC (15 years, 4 months ago) by niro
File MIME type: text/plain
File size: 1636 byte(s)
tagged 'mkinitrd-6_1_2'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Utility routines. |
4 | * |
5 | * Copyright (C) Manuel Novoa III <mjn3@codepoet.org> |
6 | * and Vladimir Oleynik <dzo@simtreas.ru> |
7 | * |
8 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
9 | */ |
10 | |
11 | #include "libbb.h" |
12 | |
13 | #define WANT_HEX_ESCAPES 1 |
14 | |
15 | /* Usual "this only works for ascii compatible encodings" disclaimer. */ |
16 | #undef _tolower |
17 | #define _tolower(X) ((X)|((char) 0x20)) |
18 | |
19 | char FAST_FUNC bb_process_escape_sequence(const char **ptr) |
20 | { |
21 | /* bash builtin "echo -e '\ec'" interprets \e as ESC, |
22 | * but coreutils "/bin/echo -e '\ec'" does not. |
23 | * manpages tend to support coreutils way. */ |
24 | static const char charmap[] ALIGN1 = { |
25 | 'a', 'b', /*'e',*/ 'f', 'n', 'r', 't', 'v', '\\', 0, |
26 | '\a', '\b', /*27,*/ '\f', '\n', '\r', '\t', '\v', '\\', '\\' }; |
27 | |
28 | const char *p; |
29 | const char *q; |
30 | unsigned num_digits; |
31 | unsigned r; |
32 | unsigned n; |
33 | unsigned d; |
34 | unsigned base; |
35 | |
36 | num_digits = n = 0; |
37 | base = 8; |
38 | q = *ptr; |
39 | |
40 | #ifdef WANT_HEX_ESCAPES |
41 | if (*q == 'x') { |
42 | ++q; |
43 | base = 16; |
44 | ++num_digits; |
45 | } |
46 | #endif |
47 | |
48 | do { |
49 | d = (unsigned char)(*q) - '0'; |
50 | #ifdef WANT_HEX_ESCAPES |
51 | if (d >= 10) { |
52 | d = (unsigned char)(_tolower(*q)) - 'a' + 10; |
53 | } |
54 | #endif |
55 | |
56 | if (d >= base) { |
57 | #ifdef WANT_HEX_ESCAPES |
58 | if ((base == 16) && (!--num_digits)) { |
59 | /* return '\\'; */ |
60 | --q; |
61 | } |
62 | #endif |
63 | break; |
64 | } |
65 | |
66 | r = n * base + d; |
67 | if (r > UCHAR_MAX) { |
68 | break; |
69 | } |
70 | |
71 | n = r; |
72 | ++q; |
73 | } while (++num_digits < 3); |
74 | |
75 | if (num_digits == 0) { /* mnemonic escape sequence? */ |
76 | p = charmap; |
77 | do { |
78 | if (*p == *q) { |
79 | q++; |
80 | break; |
81 | } |
82 | } while (*++p); |
83 | n = *(p + (sizeof(charmap)/2)); |
84 | } |
85 | |
86 | *ptr = q; |
87 | |
88 | return (char) n; |
89 | } |