1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/tools/lib/string.c
4 *
5 * Copied from linux/lib/string.c, where it is:
6 *
7 * Copyright (C) 1991, 1992 Linus Torvalds
8 *
9 * More specifically, the first copied function was strtobool, which
10 * was introduced by:
11 *
12 * d0f1fed29e6e ("Add a strtobool function matching semantics of existing in kernel equivalents")
13 * Author: Jonathan Cameron <jic23@cam.ac.uk>
14 */
15
16 #include <stdlib.h>
17 #include <string.h>
18 #include <errno.h>
19 #include <linux/string.h>
20 #include <linux/ctype.h>
21 #include <linux/compiler.h>
22
23 /**
24 * memdup - duplicate region of memory
25 *
26 * @src: memory region to duplicate
27 * @len: memory region length
28 */
memdup(const void * src,size_t len)29 void *memdup(const void *src, size_t len)
30 {
31 void *p = malloc(len);
32
33 if (p)
34 memcpy(p, src, len);
35
36 return p;
37 }
38
39 /**
40 * strtobool - convert common user inputs into boolean values
41 * @s: input string
42 * @res: result
43 *
44 * This routine returns 0 iff the first character is one of 'Yy1Nn0', or
45 * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL. Value
46 * pointed to by res is updated upon finding a match.
47 */
strtobool(const char * s,bool * res)48 int strtobool(const char *s, bool *res)
49 {
50 if (!s)
51 return -EINVAL;
52
53 switch (s[0]) {
54 case 'y':
55 case 'Y':
56 case '1':
57 *res = true;
58 return 0;
59 case 'n':
60 case 'N':
61 case '0':
62 *res = false;
63 return 0;
64 case 'o':
65 case 'O':
66 switch (s[1]) {
67 case 'n':
68 case 'N':
69 *res = true;
70 return 0;
71 case 'f':
72 case 'F':
73 *res = false;
74 return 0;
75 default:
76 break;
77 }
78 default:
79 break;
80 }
81
82 return -EINVAL;
83 }
84
85 /**
86 * strlcpy - Copy a C-string into a sized buffer
87 * @dest: Where to copy the string to
88 * @src: Where to copy the string from
89 * @size: size of destination buffer
90 *
91 * Compatible with *BSD: the result is always a valid
92 * NUL-terminated string that fits in the buffer (unless,
93 * of course, the buffer size is zero). It does not pad
94 * out the result like strncpy() does.
95 *
96 * If libc has strlcpy() then that version will override this
97 * implementation:
98 */
strlcpy(char * dest,const char * src,size_t size)99 size_t __weak strlcpy(char *dest, const char *src, size_t size)
100 {
101 size_t ret = strlen(src);
102
103 if (size) {
104 size_t len = (ret >= size) ? size - 1 : ret;
105 memcpy(dest, src, len);
106 dest[len] = '\0';
107 }
108 return ret;
109 }
110
111 /**
112 * skip_spaces - Removes leading whitespace from @str.
113 * @str: The string to be stripped.
114 *
115 * Returns a pointer to the first non-whitespace character in @str.
116 */
skip_spaces(const char * str)117 char *skip_spaces(const char *str)
118 {
119 while (isspace(*str))
120 ++str;
121 return (char *)str;
122 }
123
124 /**
125 * strim - Removes leading and trailing whitespace from @s.
126 * @s: The string to be stripped.
127 *
128 * Note that the first trailing whitespace is replaced with a %NUL-terminator
129 * in the given string @s. Returns a pointer to the first non-whitespace
130 * character in @s.
131 */
strim(char * s)132 char *strim(char *s)
133 {
134 size_t size;
135 char *end;
136
137 size = strlen(s);
138 if (!size)
139 return s;
140
141 end = s + size - 1;
142 while (end >= s && isspace(*end))
143 end--;
144 *(end + 1) = '\0';
145
146 return skip_spaces(s);
147 }
148
149 /**
150 * strreplace - Replace all occurrences of character in string.
151 * @s: The string to operate on.
152 * @old: The character being replaced.
153 * @new: The character @old is replaced with.
154 *
155 * Returns pointer to the nul byte at the end of @s.
156 */
strreplace(char * s,char old,char new)157 char *strreplace(char *s, char old, char new)
158 {
159 for (; *s; ++s)
160 if (*s == old)
161 *s = new;
162 return s;
163 }
164
