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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 <[email protected]>
- * - 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 <[email protected]>,
- * Matthew Hawkins <[email protected]>
- * - Kissed strtok() goodbye
- */
-
- #include <linux/types.h>
- #include <linux/string.h>
- #include <linux/ctype.h>
- #include <linux/module.h>
-
- #ifndef __HAVE_ARCH_STRNICMP
- /**
- * strnicmp - Case insensitive, length-limited string comparison
- * @s1: One string
- * @s2: The other string
- * @len: the maximum number of characters to compare
- */
- int strnicmp(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(strnicmp);
- #endif
-
- #ifndef __HAVE_ARCH_STRCASECMP
- int 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_STRNCASECMP
- int strncasecmp(const char *s1, const char *s2, size_t n)
- {
- int c1, c2;
-
- do {
- c1 = tolower(*s1++);
- c2 = tolower(*s2++);
- } while ((--n > 0) && c1 == c2 && c1 != 0);
- return c1 - c2;
- }
- EXPORT_SYMBOL(strncasecmp);
- #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 strcpy
- char *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, %NUL-terminated 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 %NUL terminated 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 strcat
- char *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, %NUL-terminated 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, %NUL-terminated 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 strcmp
- int 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_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;
-
- s = skip_spaces(s);
- size = strlen(s);
- if (!size)
- return s;
-
- end = s + size - 1;
- while (end >= s && isspace(*end))
- end--;
- *(end + 1) = '\0';
-
- return 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
- *
- * strsep() updates @s to point after the token, ready for the next call.
- *
- * It returns empty tokens, too, behaving exactly like the libc function
- * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
- * Same semantics, slimmer shape. ;)
- */
- char *strsep(char **s, const char *ct)
- {
- char *sbegin = *s;
- char *end;
-
- if (sbegin == NULL)
- return NULL;
-
- end = strpbrk(sbegin, ct);
- if (end)
- *end++ = '\0';
- *s = end;
- return sbegin;
- }
- EXPORT_SYMBOL(strsep);
- #endif
-
- /**
- * sysfs_streq - return true if strings are equal, modulo trailing newline
- * @s1: one string
- * @s2: another string
- *
- * This routine returns true iff two strings are equal, treating both
- * NUL and newline-then-NUL as equivalent string terminations. It's
- * geared for use with sysfs input strings, which generally terminate
- * with newlines but are compared against values without newlines.
- */
- bool sysfs_streq(const char *s1, const char *s2)
- {
- while (*s1 && *s1 == *s2) {
- s1++;
- s2++;
- }
-
- if (*s1 == *s2)
- return true;
- if (!*s1 && *s2 == '\n' && !s2[1])
- return true;
- if (*s1 == '\n' && !s1[1] && !*s2)
- return true;
- return false;
- }
- EXPORT_SYMBOL(sysfs_streq);
-
- #ifndef __HAVE_ARCH_MEMSET
- /**
- * memset - Fill a region of memory with the given value
- * @s: Pointer to the start of the area.
- * @c: The byte to fill the area with
- * @count: The size of the area.
- *
- * Do not use memset() to access IO space, use memset_io() instead.
- */
- void *memset(void *s, int c, size_t count)
- {
- char *xs = s;
-
- while (count--)
- *xs++ = c;
- return s;
- }
- EXPORT_SYMBOL(memset);
- #endif
-
- #ifndef __HAVE_ARCH_MEMCPY
- /**
- * memcpy - Copy one area of memory to another
- * @dest: Where to copy to
- * @src: Where to copy from
- * @count: The size of the area.
- *
- * You should not use this function to access IO space, use memcpy_toio()
- * or memcpy_fromio() instead.
- */
- void *memcpy(void *dest, const void *src, size_t count)
- {
- char *tmp = dest;
- const char *s = src;
-
- while (count--)
- *tmp++ = *s++;
- return dest;
- }
- EXPORT_SYMBOL(memcpy);
- #endif
-
- #ifndef __HAVE_ARCH_MEMMOVE
- /**
- * memmove - Copy one area of memory to another
- * @dest: Where to copy to
- * @src: Where to copy from
- * @count: The size of the area.
- *
- * Unlike memcpy(), memmove() copes with overlapping areas.
- */
- void *memmove(void *dest, const void *src, size_t count)
- {
- char *tmp;
- const char *s;
-
- if (dest <= src) {
- tmp = dest;
- s = src;
- while (count--)
- *tmp++ = *s++;
- } else {
- tmp = dest;
- tmp += count;
- s = src;
- s += count;
- while (count--)
- *--tmp = *--s;
- }
- return dest;
- }
- EXPORT_SYMBOL(memmove);
- #endif
-
- #ifndef __HAVE_ARCH_MEMCMP
- /**
- * memcmp - Compare two areas of memory
- * @cs: One area of memory
- * @ct: Another area of memory
- * @count: The size of the area.
- */
- #undef memcmp
- int memcmp(const void *cs, const void *ct, size_t count)
- {
- const unsigned char *su1, *su2;
- int res = 0;
-
- for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
- if ((res = *su1 - *su2) != 0)
- break;
- return res;
- }
- EXPORT_SYMBOL(memcmp);
- #endif
-
- #ifndef __HAVE_ARCH_MEMSCAN
- /**
- * memscan - Find a character in an area of memory.
- * @addr: The memory area
- * @c: The byte to search for
- * @size: The size of the area.
- *
- * returns the address of the first occurrence of @c, or 1 byte past
- * the area if @c is not found
- */
- void *memscan(void *addr, int c, size_t size)
- {
- unsigned char *p = addr;
-
- while (size) {
- if (*p == c)
- return (void *)p;
- p++;
- size--;
- }
- return (void *)p;
- }
- EXPORT_SYMBOL(memscan);
- #endif
-
- #ifndef __HAVE_ARCH_STRSTR
- /**
- * strstr - Find the first substring in a %NUL terminated string
- * @s1: The string to be searched
- * @s2: The string to search for
- */
- char *strstr(const char *s1, const char *s2)
- {
- size_t l1, l2;
-
- l2 = strlen(s2);
- if (!l2)
- return (char *)s1;
- l1 = strlen(s1);
- while (l1 >= l2) {
- l1--;
- if (!memcmp(s1, s2, l2))
- return (char *)s1;
- s1++;
- }
- return NULL;
- }
- EXPORT_SYMBOL(strstr);
- #endif
-
- #ifndef __HAVE_ARCH_STRNSTR
- /**
- * strnstr - Find the first substring in a length-limited string
- * @s1: The string to be searched
- * @s2: The string to search for
- * @len: the maximum number of characters to search
- */
- char *strnstr(const char *s1, const char *s2, size_t len)
- {
- size_t l2;
-
- l2 = strlen(s2);
- if (!l2)
- return (char *)s1;
- while (len >= l2) {
- len--;
- if (!memcmp(s1, s2, l2))
- return (char *)s1;
- s1++;
- }
- return NULL;
- }
- EXPORT_SYMBOL(strnstr);
- #endif
-
- #ifndef __HAVE_ARCH_MEMCHR
- /**
- * memchr - Find a character in an area of memory.
- * @s: The memory area
- * @c: The byte to search for
- * @n: The size of the area.
- *
- * returns the address of the first occurrence of @c, or %NULL
- * if @c is not found
- */
- void *memchr(const void *s, int c, size_t n)
- {
- const unsigned char *p = s;
- while (n-- != 0) {
- if ((unsigned char)c == *p++) {
- return (void *)(p - 1);
- }
- }
- return NULL;
- }
- EXPORT_SYMBOL(memchr);
- #endif
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