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
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
/**
* slibc — Yet another C library
* Copyright © 2015 Mattias Andrée (maandree@member.fsf.org)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <string.h>
# pragma GCC diagnostic ignored "-Wdiscarded-qualifiers"
/**
* Find the first occurrence of a byte in a memory segment.
*
* @param segment The memory segment to search.
* @param c The sought after character.
* @param size The size of the memory segment.
* @return Pointer to the first occurrence of `c`,
* `NULL` if none were found.
*/
void* memchr(const void* segment, int c, size_t size)
{
char* s = segment;
while (size--)
if (*s++ == c)
return s - 1;
return NULL;
}
/**
* Find the first occurrence of a byte in a memory segment.
* The memory segment must be known to contain the sought after byte.
*
* This is a GNU-compliant slibc extension.
*
* @param segment The memory segment to search.
* @param c The sought after character.
* @return Pointer to the first occurrence of `c`.
*/
void* rawmemchr(const void* segment, int c)
{
char* s = segment;
for (;;)
if (*s++ == c)
return s - 1;
}
/**
* Find the last occurrence of a byte in a memory segment.
*
* For improved performace, use this function instead
* of `strrchr` if you already know the length of the
* string.
*
* @param segment The memory segment to search.
* @param c The sought after character.
* @param size The size of the memory segment.
* @return Pointer to the last occurrence of `c`,
* `NULL` if none were found.
*/
void* memrchr(const void* segment, int c, size_t size)
{
char* s = segment;
while (size--)
if (s[size] == c)
return s + size;
return NULL;
}
/**
* Find the first occurrence of a byte in a string.
*
* `s = strchr(s, 0)` is a faster alternative to
* `s = s + strlen(s)`.
*
* @param string The string to search.
* The terminating NUL character is
* considered a part of the string.
* @param c The sought after character.
* @return Pointer to the first occurrence of `c`,
* `NULL` if none were found.
*/
char* strchr(const char* string, int c)
{
for (;;)
if (*string == c)
return string;
else if (!*string++)
return NULL;
}
/**
* Find the first occurrence of a byte in a string, or
* if there is no such byte, the end of the string.
*
* This is a GNU-compliant slibc extension.
*
* @param string The string to search.
* The terminating NUL character is
* considered a part of the string.
* @param c The sought after character.
* @return Pointer to the first occurrence of `c`,
* Pointer to the terminating NUL character
* if none were found.
*/
char* strchrnul(const char* string, int c)
{
for (;; string++)
if (*string == c)
return string;
else if (!*string)
return string;
}
/**
* Find the last occurrence of a byte in a string.
*
* For improved performace, use `memrchr` instead of
* this function if you already know the length of the
* string.
*
* @param string The string to search.
* The terminating NUL character is
* considered a part of the string.
* @param c The sought after character.
* @return Pointer to the last occurrence of `c`,
* `NULL` if none were found.
*/
char* strrchr(const char* string, int c)
{
char* r = NULL;
for (;;)
if (*string == c)
r = string;
else if (!*string++)
return r;
}
|
