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1/* -*- linux-c -*- ------------------------------------------------------- *
2 *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright 2007 rPath, Inc. - All Rights Reserved
5 *
6 * This file is part of the Linux kernel, and is made available under
7 * the terms of the GNU General Public License version 2.
8 *
9 * ----------------------------------------------------------------------- */
10
11/*
12 * Very basic string functions
13 */
14
15#include "boot.h"
16
17/*
18 * This file gets included in compressed/string.c which might pull in
19 * string_32.h and which in turn maps memcmp to __builtin_memcmp(). Undo
20 * that first.
21 */
22#undef memcmp
23int memcmp(const void *s1, const void *s2, size_t len)
24{
25 u8 diff;
26 asm("repe; cmpsb; setnz %0"
27 : "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));
28 return diff;
29}
30
31int strcmp(const char *str1, const char *str2)
32{
33 const unsigned char *s1 = (const unsigned char *)str1;
34 const unsigned char *s2 = (const unsigned char *)str2;
35 int delta = 0;
36
37 while (*s1 || *s2) {
38 delta = *s2 - *s1;
39 if (delta)
40 return delta;
41 s1++;
42 s2++;
43 }
44 return 0;
45}
46
47int strncmp(const char *cs, const char *ct, size_t count)
48{
49 unsigned char c1, c2;
50
51 while (count) {
52 c1 = *cs++;
53 c2 = *ct++;
54 if (c1 != c2)
55 return c1 < c2 ? -1 : 1;
56 if (!c1)
57 break;
58 count--;
59 }
60 return 0;
61}
62
63size_t strnlen(const char *s, size_t maxlen)
64{
65 const char *es = s;
66 while (*es && maxlen) {
67 es++;
68 maxlen--;
69 }
70
71 return (es - s);
72}
73
74unsigned int atou(const char *s)
75{
76 unsigned int i = 0;
77 while (isdigit(*s))
78 i = i * 10 + (*s++ - '0');
79 return i;
80}
81
82/* Works only for digits and letters, but small and fast */
83#define TOLOWER(x) ((x) | 0x20)
84
85static unsigned int simple_guess_base(const char *cp)
86{
87 if (cp[0] == '0') {
88 if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
89 return 16;
90 else
91 return 8;
92 } else {
93 return 10;
94 }
95}
96
97/**
98 * simple_strtoull - convert a string to an unsigned long long
99 * @cp: The start of the string
100 * @endp: A pointer to the end of the parsed string will be placed here
101 * @base: The number base to use
102 */
103
104unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
105{
106 unsigned long long result = 0;
107
108 if (!base)
109 base = simple_guess_base(cp);
110
111 if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
112 cp += 2;
113
114 while (isxdigit(*cp)) {
115 unsigned int value;
116
117 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
118 if (value >= base)
119 break;
120 result = result * base + value;
121 cp++;
122 }
123 if (endp)
124 *endp = (char *)cp;
125
126 return result;
127}
128
129/**
130 * strlen - Find the length of a string
131 * @s: The string to be sized
132 */
133size_t strlen(const char *s)
134{
135 const char *sc;
136
137 for (sc = s; *sc != '\0'; ++sc)
138 /* nothing */;
139 return sc - s;
140}
141
142/**
143 * strstr - Find the first substring in a %NUL terminated string
144 * @s1: The string to be searched
145 * @s2: The string to search for
146 */
147char *strstr(const char *s1, const char *s2)
148{
149 size_t l1, l2;
150
151 l2 = strlen(s2);
152 if (!l2)
153 return (char *)s1;
154 l1 = strlen(s1);
155 while (l1 >= l2) {
156 l1--;
157 if (!memcmp(s1, s2, l2))
158 return (char *)s1;
159 s1++;
160 }
161 return NULL;
162}
1/* -*- linux-c -*- ------------------------------------------------------- *
2 *
3 * Copyright (C) 1991, 1992 Linus Torvalds
4 * Copyright 2007 rPath, Inc. - All Rights Reserved
5 *
6 * This file is part of the Linux kernel, and is made available under
7 * the terms of the GNU General Public License version 2.
8 *
9 * ----------------------------------------------------------------------- */
10
11/*
12 * Very basic string functions
13 */
14
15#include <linux/types.h>
16#include "ctype.h"
17
18int memcmp(const void *s1, const void *s2, size_t len)
19{
20 u8 diff;
21 asm("repe; cmpsb; setnz %0"
22 : "=qm" (diff), "+D" (s1), "+S" (s2), "+c" (len));
23 return diff;
24}
25
26int strcmp(const char *str1, const char *str2)
27{
28 const unsigned char *s1 = (const unsigned char *)str1;
29 const unsigned char *s2 = (const unsigned char *)str2;
30 int delta = 0;
31
32 while (*s1 || *s2) {
33 delta = *s1 - *s2;
34 if (delta)
35 return delta;
36 s1++;
37 s2++;
38 }
39 return 0;
40}
41
42int strncmp(const char *cs, const char *ct, size_t count)
43{
44 unsigned char c1, c2;
45
46 while (count) {
47 c1 = *cs++;
48 c2 = *ct++;
49 if (c1 != c2)
50 return c1 < c2 ? -1 : 1;
51 if (!c1)
52 break;
53 count--;
54 }
55 return 0;
56}
57
58size_t strnlen(const char *s, size_t maxlen)
59{
60 const char *es = s;
61 while (*es && maxlen) {
62 es++;
63 maxlen--;
64 }
65
66 return (es - s);
67}
68
69unsigned int atou(const char *s)
70{
71 unsigned int i = 0;
72 while (isdigit(*s))
73 i = i * 10 + (*s++ - '0');
74 return i;
75}
76
77/* Works only for digits and letters, but small and fast */
78#define TOLOWER(x) ((x) | 0x20)
79
80static unsigned int simple_guess_base(const char *cp)
81{
82 if (cp[0] == '0') {
83 if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2]))
84 return 16;
85 else
86 return 8;
87 } else {
88 return 10;
89 }
90}
91
92/**
93 * simple_strtoull - convert a string to an unsigned long long
94 * @cp: The start of the string
95 * @endp: A pointer to the end of the parsed string will be placed here
96 * @base: The number base to use
97 */
98
99unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base)
100{
101 unsigned long long result = 0;
102
103 if (!base)
104 base = simple_guess_base(cp);
105
106 if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x')
107 cp += 2;
108
109 while (isxdigit(*cp)) {
110 unsigned int value;
111
112 value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10;
113 if (value >= base)
114 break;
115 result = result * base + value;
116 cp++;
117 }
118 if (endp)
119 *endp = (char *)cp;
120
121 return result;
122}
123
124/**
125 * strlen - Find the length of a string
126 * @s: The string to be sized
127 */
128size_t strlen(const char *s)
129{
130 const char *sc;
131
132 for (sc = s; *sc != '\0'; ++sc)
133 /* nothing */;
134 return sc - s;
135}
136
137/**
138 * strstr - Find the first substring in a %NUL terminated string
139 * @s1: The string to be searched
140 * @s2: The string to search for
141 */
142char *strstr(const char *s1, const char *s2)
143{
144 size_t l1, l2;
145
146 l2 = strlen(s2);
147 if (!l2)
148 return (char *)s1;
149 l1 = strlen(s1);
150 while (l1 >= l2) {
151 l1--;
152 if (!memcmp(s1, s2, l2))
153 return (char *)s1;
154 s1++;
155 }
156 return NULL;
157}