Annotation of prex/sys/lib/string.c, Revision 1.1.1.1
1.1 nbrk 1: /*-
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 <sys/types.h>
35: #include <kernel.h>
36:
37: /*
38: * Safer version of strncpy
39: * The destination string is always terminated with NULL character.
40: */
41: size_t
42: strlcpy(char *dest, const char *src, size_t count)
43: {
44: char *d = dest;
45: const char *s = src;
46: size_t n = count;
47:
48: /* Copy as many bytes as will fit */
49: if (n != 0 && --n != 0) {
50: do {
51: if ((*d++ = *s++) == 0)
52: break;
53: } while (--n != 0);
54: }
55:
56: /* Not enough room in dst, add NUL and traverse rest of src */
57: if (n == 0) {
58: if (count != 0)
59: *d = '\0'; /* NUL-terminate dst */
60: while (*s++)
61: ;
62: }
63:
64: return (size_t)(s - src - 1); /* count does not include NUL */
65: }
66:
67: int
68: strncmp(const char *src, const char *tgt, size_t count)
69: {
70: signed char res = 0;
71:
72: while (count) {
73: if ((res = *src - *tgt++) != 0 || !*src++)
74: break;
75: count--;
76: }
77: return res;
78: }
79:
80: /* The returned size does not include the last NULL char */
81: size_t
82: strnlen(const char *str, size_t count)
83: {
84: const char *tmp;
85:
86: for (tmp = str; count-- && *tmp != '\0'; ++tmp);
87: return (size_t)(tmp - str);
88: }
89:
90: void *
91: memcpy(void *dest, const void *src, size_t count)
92: {
93: char *tmp = (char *)dest, *s = (char *)src;
94:
95: while (count--)
96: *tmp++ = *s++;
97:
98: return dest;
99: }
100:
101: void *
102: memset(void *dest, int ch, size_t count)
103: {
104: char *p = (char *)dest;
105:
106: while (count--)
107: *p++ = (char)ch;
108:
109: return dest;
110: }
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