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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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