xref: /linux/tools/lib/string.c (revision 4246b92cf9fb32da8d8b060c92d8302797c6fbea)
1 /*
2  *  linux/tools/lib/string.c
3  *
4  *  Copied from linux/lib/string.c, where it is:
5  *
6  *  Copyright (C) 1991, 1992  Linus Torvalds
7  *
8  *  More specifically, the first copied function was strtobool, which
9  *  was introduced by:
10  *
11  *  d0f1fed29e6e ("Add a strtobool function matching semantics of existing in kernel equivalents")
12  *  Author: Jonathan Cameron <jic23@cam.ac.uk>
13  */
14 
15 #include <stdlib.h>
16 #include <string.h>
17 #include <errno.h>
18 #include <linux/string.h>
19 #include <linux/compiler.h>
20 
21 /**
22  * memdup - duplicate region of memory
23  *
24  * @src: memory region to duplicate
25  * @len: memory region length
26  */
27 void *memdup(const void *src, size_t len)
28 {
29 	void *p = malloc(len);
30 
31 	if (p)
32 		memcpy(p, src, len);
33 
34 	return p;
35 }
36 
37 /**
38  * strtobool - convert common user inputs into boolean values
39  * @s: input string
40  * @res: result
41  *
42  * This routine returns 0 iff the first character is one of 'Yy1Nn0', or
43  * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL.  Value
44  * pointed to by res is updated upon finding a match.
45  */
46 int strtobool(const char *s, bool *res)
47 {
48 	if (!s)
49 		return -EINVAL;
50 
51 	switch (s[0]) {
52 	case 'y':
53 	case 'Y':
54 	case '1':
55 		*res = true;
56 		return 0;
57 	case 'n':
58 	case 'N':
59 	case '0':
60 		*res = false;
61 		return 0;
62 	case 'o':
63 	case 'O':
64 		switch (s[1]) {
65 		case 'n':
66 		case 'N':
67 			*res = true;
68 			return 0;
69 		case 'f':
70 		case 'F':
71 			*res = false;
72 			return 0;
73 		default:
74 			break;
75 		}
76 	default:
77 		break;
78 	}
79 
80 	return -EINVAL;
81 }
82 
83 /**
84  * strlcpy - Copy a C-string into a sized buffer
85  * @dest: Where to copy the string to
86  * @src: Where to copy the string from
87  * @size: size of destination buffer
88  *
89  * Compatible with *BSD: the result is always a valid
90  * NUL-terminated string that fits in the buffer (unless,
91  * of course, the buffer size is zero). It does not pad
92  * out the result like strncpy() does.
93  *
94  * If libc has strlcpy() then that version will override this
95  * implementation:
96  */
97 size_t __weak strlcpy(char *dest, const char *src, size_t size)
98 {
99 	size_t ret = strlen(src);
100 
101 	if (size) {
102 		size_t len = (ret >= size) ? size - 1 : ret;
103 		memcpy(dest, src, len);
104 		dest[len] = '\0';
105 	}
106 	return ret;
107 }
108