root / prex-0.9.0 / sys / lib / string.c @ 03e9c04a
History | View | Annotate | Download (2.88 KB)
1 | 03e9c04a | Brad Neuman | /*-
|
---|---|---|---|
2 | * Copyright (c) 2005-2006, Kohsuke Ohtani
|
||
3 | * All rights reserved.
|
||
4 | *
|
||
5 | * Redistribution and use in source and binary forms, with or without
|
||
6 | * modification, are permitted provided that the following conditions
|
||
7 | * are met:
|
||
8 | * 1. Redistributions of source code must retain the above copyright
|
||
9 | * notice, this list of conditions and the following disclaimer.
|
||
10 | * 2. Redistributions in binary form must reproduce the above copyright
|
||
11 | * notice, this list of conditions and the following disclaimer in the
|
||
12 | * documentation and/or other materials provided with the distribution.
|
||
13 | * 3. Neither the name of the author nor the names of any co-contributors
|
||
14 | * may be used to endorse or promote products derived from this software
|
||
15 | * without specific prior written permission.
|
||
16 | *
|
||
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
||
18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||
20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
||
21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||
22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||
23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||
24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||
25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||
26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||
27 | * SUCH DAMAGE.
|
||
28 | */
|
||
29 | |||
30 | /*
|
||
31 | * string.c - Minimum string library for kernel
|
||
32 | */
|
||
33 | |||
34 | #include <kernel.h> |
||
35 | |||
36 | /*
|
||
37 | * Safer version of strncpy
|
||
38 | * The destination string is always terminated with NULL character.
|
||
39 | */
|
||
40 | size_t |
||
41 | strlcpy(char *dest, const char *src, size_t count) |
||
42 | { |
||
43 | char *d = dest;
|
||
44 | const char *s = src; |
||
45 | size_t n = count; |
||
46 | |||
47 | /* Copy as many bytes as will fit */
|
||
48 | if (n != 0 && --n != 0) { |
||
49 | do {
|
||
50 | if ((*d++ = *s++) == 0) |
||
51 | break;
|
||
52 | } while (--n != 0); |
||
53 | } |
||
54 | |||
55 | /* Not enough room in dst, add NUL and traverse rest of src */
|
||
56 | if (n == 0) { |
||
57 | if (count != 0) |
||
58 | *d = '\0'; /* NUL-terminate dst */ |
||
59 | while (*s++)
|
||
60 | ; |
||
61 | } |
||
62 | |||
63 | return (size_t)(s - src - 1); /* count does not include NUL */ |
||
64 | } |
||
65 | |||
66 | int
|
||
67 | strncmp(const char *src, const char *tgt, size_t count) |
||
68 | { |
||
69 | signed char res = 0; |
||
70 | |||
71 | while (count) {
|
||
72 | if ((res = *src - *tgt++) != 0 || !*src++) |
||
73 | break;
|
||
74 | count--; |
||
75 | } |
||
76 | return res;
|
||
77 | } |
||
78 | |||
79 | /* The returned size does not include the last NULL char */
|
||
80 | size_t |
||
81 | strnlen(const char *str, size_t count) |
||
82 | { |
||
83 | const char *tmp; |
||
84 | |||
85 | for (tmp = str; count-- && *tmp != '\0'; ++tmp); |
||
86 | return (size_t)(tmp - str);
|
||
87 | } |
||
88 | |||
89 | void *
|
||
90 | memcpy(void *dest, const void *src, size_t count) |
||
91 | { |
||
92 | char *tmp = (char *)dest, *s = (char *)src; |
||
93 | |||
94 | ASSERT(count != 0);
|
||
95 | |||
96 | while (count--)
|
||
97 | *tmp++ = *s++; |
||
98 | |||
99 | return dest;
|
||
100 | } |
||
101 | |||
102 | void *
|
||
103 | memset(void *dest, int ch, size_t count) |
||
104 | { |
||
105 | char *p = (char *)dest; |
||
106 | |||
107 | ASSERT(count != 0);
|
||
108 | |||
109 | while (count--)
|
||
110 | *p++ = (char)ch;
|
||
111 | |||
112 | return dest;
|
||
113 | } |