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/compiler.h> 21 22 /** 23 * memdup - duplicate region of memory 24 * 25 * @src: memory region to duplicate 26 * @len: memory region length 27 */ 28 void *memdup(const void *src, size_t len) 29 { 30 void *p = malloc(len); 31 32 if (p) 33 memcpy(p, src, len); 34 35 return p; 36 } 37 38 /** 39 * strtobool - convert common user inputs into boolean values 40 * @s: input string 41 * @res: result 42 * 43 * This routine returns 0 iff the first character is one of 'Yy1Nn0', or 44 * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL. Value 45 * pointed to by res is updated upon finding a match. 46 */ 47 int strtobool(const char *s, bool *res) 48 { 49 if (!s) 50 return -EINVAL; 51 52 switch (s[0]) { 53 case 'y': 54 case 'Y': 55 case '1': 56 *res = true; 57 return 0; 58 case 'n': 59 case 'N': 60 case '0': 61 *res = false; 62 return 0; 63 case 'o': 64 case 'O': 65 switch (s[1]) { 66 case 'n': 67 case 'N': 68 *res = true; 69 return 0; 70 case 'f': 71 case 'F': 72 *res = false; 73 return 0; 74 default: 75 break; 76 } 77 default: 78 break; 79 } 80 81 return -EINVAL; 82 } 83 84 /** 85 * strlcpy - Copy a C-string into a sized buffer 86 * @dest: Where to copy the string to 87 * @src: Where to copy the string from 88 * @size: size of destination buffer 89 * 90 * Compatible with *BSD: the result is always a valid 91 * NUL-terminated string that fits in the buffer (unless, 92 * of course, the buffer size is zero). It does not pad 93 * out the result like strncpy() does. 94 * 95 * If libc has strlcpy() then that version will override this 96 * implementation: 97 */ 98 size_t __weak strlcpy(char *dest, const char *src, size_t size) 99 { 100 size_t ret = strlen(src); 101 102 if (size) { 103 size_t len = (ret >= size) ? size - 1 : ret; 104 memcpy(dest, src, len); 105 dest[len] = '\0'; 106 } 107 return ret; 108 } 109