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// SPDX-License-Identifier: GPL-2.0/* *  linux/tools/lib/string.c * *  Copied from linux/lib/string.c, where it is: * *  Copyright (C) 1991, 1992  Linus Torvalds * *  More specifically, the first copied function was strtobool, which *  was introduced by: * *  d0f1fed29e6e ("Add a strtobool function matching semantics of existing in kernel equivalents") *  Author: Jonathan Cameron <jic23@cam.ac.uk> */ #include <stdlib.h>#include <string.h>#include <errno.h>#include <linux/string.h>#include <linux/ctype.h>#include <linux/compiler.h> /** * memdup - duplicate region of memory * * @src: memory region to duplicate * @len: memory region length */void *memdup(const void *src, size_t len){	void *p = malloc(len); 	if (p)		memcpy(p, src, len); 	return p;} /** * strtobool - convert common user inputs into boolean values * @s: input string * @res: result * * This routine returns 0 iff the first character is one of 'Yy1Nn0', or * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL.  Value * pointed to by res is updated upon finding a match. */int strtobool(const char *s, bool *res){	if (!s)		return -EINVAL; 	switch (s[0]) {	case 'y':	case 'Y':	case '1':		*res = true;		return 0;	case 'n':	case 'N':	case '0':		*res = false;		return 0;	case 'o':	case 'O':		switch (s[1]) {		case 'n':		case 'N':			*res = true;			return 0;		case 'f':		case 'F':			*res = false;			return 0;		default:			break;		}	default:		break;	} 	return -EINVAL;} /** * strlcpy - Copy a C-string into a sized buffer * @dest: Where to copy the string to * @src: Where to copy the string from * @size: size of destination buffer * * Compatible with *BSD: the result is always a valid * NUL-terminated string that fits in the buffer (unless, * of course, the buffer size is zero). It does not pad * out the result like strncpy() does. * * If libc has strlcpy() then that version will override this * implementation: */#ifdef __clang__#pragma clang diagnostic push#pragma clang diagnostic ignored "-Wignored-attributes"#endifsize_t __weak strlcpy(char *dest, const char *src, size_t size){	size_t ret = strlen(src); 	if (size) {		size_t len = (ret >= size) ? size - 1 : ret;		memcpy(dest, src, len);		dest[len] = '\0';	}	return ret;}#ifdef __clang__#pragma clang diagnostic pop#endif /** * skip_spaces - Removes leading whitespace from @str. * @str: The string to be stripped. * * Returns a pointer to the first non-whitespace character in @str. */char *skip_spaces(const char *str){	while (isspace(*str))		++str;	return (char *)str;} /** * strim - Removes leading and trailing whitespace from @s. * @s: The string to be stripped. * * Note that the first trailing whitespace is replaced with a %NUL-terminator * in the given string @s. Returns a pointer to the first non-whitespace * character in @s. */char *strim(char *s){	size_t size;	char *end; 	size = strlen(s);	if (!size)		return s; 	end = s + size - 1;	while (end >= s && isspace(*end))		end--;	*(end + 1) = '\0'; 	return skip_spaces(s);} /* * remove_spaces - Removes whitespaces from @s */void remove_spaces(char *s){	char *d = s; 	do {		while (*d == ' ')			++d;	} while ((*s++ = *d++));} /** * strreplace - Replace all occurrences of character in string. * @s: The string to operate on. * @old: The character being replaced. * @new: The character @old is replaced with. * * Returns pointer to the nul byte at the end of @s. */char *strreplace(char *s, char old, char new){	for (; *s; ++s)		if (*s == old)			*s = new;	return s;} static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes){	while (bytes) {		if (*start != value)			return (void *)start;		start++;		bytes--;	}	return NULL;} /** * memchr_inv - Find an unmatching character in an area of memory. * @start: The memory area * @c: Find a character other than c * @bytes: The size of the area. * * returns the address of the first character other than @c, or %NULL * if the whole buffer contains just @c. */void *memchr_inv(const void *start, int c, size_t bytes){	u8 value = c;	u64 value64;	unsigned int words, prefix; 	if (bytes <= 16)		return check_bytes8(start, value, bytes); 	value64 = value;	value64 |= value64 << 8;	value64 |= value64 << 16;	value64 |= value64 << 32; 	prefix = (unsigned long)start % 8;	if (prefix) {		u8 *r; 		prefix = 8 - prefix;		r = check_bytes8(start, value, prefix);		if (r)			return r;		start += prefix;		bytes -= prefix;	} 	words = bytes / 8; 	while (words) {		if (*(u64 *)start != value64)			return check_bytes8(start, value, 8);		start += 8;		words--;	} 	return check_bytes8(start, value, bytes % 8);}