aboutsummaryrefslogtreecommitdiff
path: root/src/common/libc/string.c
blob: e5f7a53ca5608fd0ee9e5d5e6c55806d26014abc (plain) (blame)
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
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
#include <string.h>
#include <malloc.h>


size_t strlen(const char* str) {
	size_t ret = 0;
	while (str[ret] != 0)
		ret++;
	return ret;
}

char *strchr(const char *str, char c) {
	do {
		if (*str == c) return (char*)str;
	} while (*(str++));
	return NULL;
}

char *strrchr(const char *str, char c) {
	char* ret = NULL;
	do {
		if (*str == c) ret = (char*)str;
	} while (*(str++));
	return ret;
}

char *strcpy(char *dest, const char *src) {
	memcpy(dest, src, strlen(src) + 1);
	return (char*)dest;
}

char *strncpy(char *dest, const char *src, size_t n) {
	size_t x = strlen(src);
	if (n < x) x = n;
	memcpy(dest, src, x);
	if (n > x) memset(dest + x, 0, n - x);
	return (char*)dest;
}

char *strcat(char *dest, const char *src) {
	char *dest2 = dest;
	dest2 += strlen(dest) - 1;
	while (*src) {
		*dest2 = *src;
		src++;
		dest2++;
	}
	*dest2 = 0;
	return dest;
}

int strcmp(const char *s1, const char *s2) {
	while ((*s1) && (*s1 == *s2)) {
		s1++;
		s2++;
	}
	return (*(unsigned char*)s1 - *(unsigned char*)s2);
}

int strncmp(const char *s1, const char *s2, size_t n) {
	size_t i = 0;
	while ((*s1) && (*s1 == *s2) && i != n) {
		s1++;
		s2++;
		i++;
	}
	return (*(unsigned char*)s1 - *(unsigned char*)s2);
}

void *memcpy(void *vd, const void *vs, size_t count) {
	uint8_t *dest = (uint8_t*)vd, *src = (uint8_t*)vs;
	size_t f = count % 4, n = count / 4, i;
	const uint32_t* s = (uint32_t*)src;
	uint32_t* d = (uint32_t*)dest;
	for (i = 0; i < n; i++) {
		d[i] = s[i];
	}
	if (f != 0) {
		for (i = count - f; i < count; i++) {
			dest[i] = src[i];
		}
	}
	return vd;
}

void *memmove(void *vd, const void *vs, size_t count) {
	uint8_t *dest = (uint8_t*)vd, *src = (uint8_t*)vs;

	if (vd < vs) {
		for (size_t i = 0; i < count; i++)
			dest[i] = src[i];
	} else {
		for (size_t i = 0; i < count; i++)
			dest[count - i] = src[count - i];
	}
	return vd;
}

int memcmp(const void *va, const void *vb, size_t count) {
	uint8_t *a = (uint8_t*)va;
	uint8_t *b = (uint8_t*)vb;
	for (size_t i = 0; i < count; i++) {
		if (a[i] != b[i]) return (int)a[i] - (int)b[i];
	}
	return 0;
}

void *memset(void *dest, int val, size_t count) {
	uint8_t *dest_c = (uint8_t*)dest;
	for (size_t i = 0; i < count; i++) {
		dest_c[i] = val;
	}
	return dest;
}

char *strdup(const char* str) {
	size_t len = strlen(str) + 1;

	char* ret = (char*)malloc(len);
	if (ret == 0) return 0;

	memcpy(ret, str, len);
	return ret;
}

char *strndup(const char* str, size_t count) {
	size_t len = strlen(str);
	if (count < len) len = count;

	char* ret = (char*)malloc(len + 1);
	if (ret == 0) return 0;

	memcpy(ret, str, len);
	ret[len] = 0;
	return ret;
}

/* vim: set ts=4 sw=4 tw=0 noet :*/