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/* *  linux/lib/string.c * *  Copyright (C) 1991, 1992  Linus Torvalds */ /* * stupid library routines.. The optimized versions should generally be found * as inline code in <asm-xx/string.h> * * These are buggy as well.. * * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de> * -  Added strsep() which will replace strtok() soon (because strsep() is *    reentrant and should be faster). Use only strsep() in new code, please. * * * Sat Feb 09 2002, Jason Thomas <jason@topic.com.au>, *                    Matthew Hawkins <matt@mh.dropbear.id.au> * -  Kissed strtok() goodbye */ #include <linux/types.h>#include <linux/string.h>#include <linux/ctype.h>#include <linux/kernel.h>#include <linux/export.h>#include <linux/bug.h>#include <linux/errno.h> #ifndef __HAVE_ARCH_STRNCASECMP/** * strncasecmp - Case insensitive, length-limited string comparison * @s1: One string * @s2: The other string * @len: the maximum number of characters to compare */int strncasecmp(const char *s1, const char *s2, size_t len){	/* Yes, Virginia, it had better be unsigned */	unsigned char c1, c2; 	if (!len)		return 0; 	do {		c1 = *s1++;		c2 = *s2++;		if (!c1 || !c2)			break;		if (c1 == c2)			continue;		c1 = tolower(c1);		c2 = tolower(c2);		if (c1 != c2)			break;	} while (--len);	return (int)c1 - (int)c2;}EXPORT_SYMBOL(strncasecmp);#endif#ifndef __HAVE_ARCH_STRNICMP#undef strnicmpint strnicmp(const char *s1, const char *s2, size_t len){	return strncasecmp(s1, s2, len);}EXPORT_SYMBOL(strnicmp);#endif #ifndef __HAVE_ARCH_STRCASECMPint strcasecmp(const char *s1, const char *s2){	int c1, c2; 	do {		c1 = tolower(*s1++);		c2 = tolower(*s2++);	} while (c1 == c2 && c1 != 0);	return c1 - c2;}EXPORT_SYMBOL(strcasecmp);#endif #ifndef __HAVE_ARCH_STRCPY/** * strcpy - Copy a %NUL terminated string * @dest: Where to copy the string to * @src: Where to copy the string from */#undef strcpychar *strcpy(char *dest, const char *src){	char *tmp = dest; 	while ((*dest++ = *src++) != '\0')		/* nothing */;	return tmp;}EXPORT_SYMBOL(strcpy);#endif #ifndef __HAVE_ARCH_STRNCPY/** * strncpy - Copy a length-limited, C-string * @dest: Where to copy the string to * @src: Where to copy the string from * @count: The maximum number of bytes to copy * * The result is not %NUL-terminated if the source exceeds * @count bytes. * * In the case where the length of @src is less than  that  of * count, the remainder of @dest will be padded with %NUL. * */char *strncpy(char *dest, const char *src, size_t count){	char *tmp = dest; 	while (count) {		if ((*tmp = *src) != 0)			src++;		tmp++;		count--;	}	return dest;}EXPORT_SYMBOL(strncpy);#endif #ifndef __HAVE_ARCH_STRLCPY/** * 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. */size_t 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;}EXPORT_SYMBOL(strlcpy);#endif #ifndef __HAVE_ARCH_STRCAT/** * strcat - Append one %NUL-terminated string to another * @dest: The string to be appended to * @src: The string to append to it */#undef strcatchar *strcat(char *dest, const char *src){	char *tmp = dest; 	while (*dest)		dest++;	while ((*dest++ = *src++) != '\0')		;	return tmp;}EXPORT_SYMBOL(strcat);#endif #ifndef __HAVE_ARCH_STRNCAT/** * strncat - Append a length-limited, C-string to another * @dest: The string to be appended to * @src: The string to append to it * @count: The maximum numbers of bytes to copy * * Note that in contrast to strncpy(), strncat() ensures the result is * terminated. */char *strncat(char *dest, const char *src, size_t count){	char *tmp = dest; 	if (count) {		while (*dest)			dest++;		while ((*dest++ = *src++) != 0) {			if (--count == 0) {				*dest = '\0';				break;			}		}	}	return tmp;}EXPORT_SYMBOL(strncat);#endif #ifndef __HAVE_ARCH_STRLCAT/** * strlcat - Append a length-limited, C-string to another * @dest: The string to be appended to * @src: The string to append to it * @count: The size of the destination buffer. */size_t strlcat(char *dest, const char *src, size_t count){	size_t dsize = strlen(dest);	size_t len = strlen(src);	size_t res = dsize + len; 	/* This would be a bug */	BUG_ON(dsize >= count); 	dest += dsize;	count -= dsize;	if (len >= count)		len = count-1;	memcpy(dest, src, len);	dest[len] = 0;	return res;}EXPORT_SYMBOL(strlcat);#endif #ifndef __HAVE_ARCH_STRCMP/** * strcmp - Compare two strings * @cs: One string * @ct: Another string */#undef strcmpint strcmp(const char *cs, const char *ct){	unsigned char c1, c2; 	while (1) {		c1 = *cs++;		c2 = *ct++;		if (c1 != c2)			return c1 < c2 ? -1 : 1;		if (!c1)			break;	}	return 0;}EXPORT_SYMBOL(strcmp);#endif #ifndef __HAVE_ARCH_STRNCMP/** * strncmp - Compare two length-limited strings * @cs: One string * @ct: Another string * @count: The maximum number of bytes to compare */int strncmp(const char *cs, const char *ct, size_t count){	unsigned char c1, c2; 	while (count) {		c1 = *cs++;		c2 = *ct++;		if (c1 != c2)			return c1 < c2 ? -1 : 1;		if (!c1)			break;		count--;	}	return 0;}EXPORT_SYMBOL(strncmp);#endif #ifndef __HAVE_ARCH_STRCHR/** * strchr - Find the first occurrence of a character in a string * @s: The string to be searched * @c: The character to search for */char *strchr(const char *s, int c){	for (; *s != (char)c; ++s)		if (*s == '\0')			return NULL;	return (char *)s;}EXPORT_SYMBOL(strchr);#endif #ifndef __HAVE_ARCH_STRCHRNUL/** * strchrnul - Find and return a character in a string, or end of string * @s: The string to be searched * @c: The character to search for * * Returns pointer to first occurrence of 'c' in s. If c is not found, then * return a pointer to the null byte at the end of s. */char *strchrnul(const char *s, int c){	while (*s && *s != (char)c)		s++;	return (char *)s;}EXPORT_SYMBOL(strchrnul);#endif #ifndef __HAVE_ARCH_STRRCHR/** * strrchr - Find the last occurrence of a character in a string * @s: The string to be searched * @c: The character to search for */char *strrchr(const char *s, int c){       const char *p = s + strlen(s);       do {           if (*p == (char)c)               return (char *)p;       } while (--p >= s);       return NULL;}EXPORT_SYMBOL(strrchr);#endif #ifndef __HAVE_ARCH_STRNCHR/** * strnchr - Find a character in a length limited string * @s: The string to be searched * @count: The number of characters to be searched * @c: The character to search for */char *strnchr(const char *s, size_t count, int c){	for (; count-- && *s != '\0'; ++s)		if (*s == (char)c)			return (char *)s;	return NULL;}EXPORT_SYMBOL(strnchr);#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;}EXPORT_SYMBOL(skip_spaces); /** * 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);}EXPORT_SYMBOL(strim); #ifndef __HAVE_ARCH_STRLEN/** * strlen - Find the length of a string * @s: The string to be sized */size_t strlen(const char *s){	const char *sc; 	for (sc = s; *sc != '\0'; ++sc)		/* nothing */;	return sc - s;}EXPORT_SYMBOL(strlen);#endif #ifndef __HAVE_ARCH_STRNLEN/** * strnlen - Find the length of a length-limited string * @s: The string to be sized * @count: The maximum number of bytes to search */size_t strnlen(const char *s, size_t count){	const char *sc; 	for (sc = s; count-- && *sc != '\0'; ++sc)		/* nothing */;	return sc - s;}EXPORT_SYMBOL(strnlen);#endif #ifndef __HAVE_ARCH_STRSPN/** * strspn - Calculate the length of the initial substring of @s which only contain letters in @accept * @s: The string to be searched * @accept: The string to search for */size_t strspn(const char *s, const char *accept){	const char *p;	const char *a;	size_t count = 0; 	for (p = s; *p != '\0'; ++p) {		for (a = accept; *a != '\0'; ++a) {			if (*p == *a)				break;		}		if (*a == '\0')			return count;		++count;	}	return count;} EXPORT_SYMBOL(strspn);#endif #ifndef __HAVE_ARCH_STRCSPN/** * strcspn - Calculate the length of the initial substring of @s which does not contain letters in @reject * @s: The string to be searched * @reject: The string to avoid */size_t strcspn(const char *s, const char *reject){	const char *p;	const char *r;	size_t count = 0; 	for (p = s; *p != '\0'; ++p) {		for (r = reject; *r != '\0'; ++r) {			if (*p == *r)				return count;		}		++count;	}	return count;}EXPORT_SYMBOL(strcspn);#endif #ifndef __HAVE_ARCH_STRPBRK/** * strpbrk - Find the first occurrence of a set of characters * @cs: The string to be searched * @ct: The characters to search for */char *strpbrk(const char *cs, const char *ct){	const char *sc1, *sc2; 	for (sc1 = cs; *sc1 != '\0'; ++sc1) {		for (sc2 = ct; *sc2 != '\0'; ++sc2) {			if (*sc1 == *sc2)				return (char *)sc1;		}	}	return NULL;}EXPORT_SYMBOL(strpbrk);#endif #ifndef __HAVE_ARCH_STRSEP/** * strsep - Split a string into tokens * @s: The string to be searched * @ct: The characters to search for

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