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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/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;
+
+ c1 = 0; c2 = 0;
+ if (len) {
+ do {
+ c1 = *s1; c2 = *s2;
+ s1++; s2++;
+ if (!c1)
+ break;
+ if (!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_STRCPY
+/**
+ * strcpy - Copy a %NUL terminated string
+ * @dest: Where to copy the string to
+ * @src: Where to copy the string from
+ */
+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.
+ */
+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
+ */
+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
+ */
+int strcmp(const char * cs,const char * ct)
+{
+ register signed char __res;
+
+ while (1) {
+ if ((__res = *cs - *ct++) != 0 || !*cs++)
+ break;
+ }
+
+ return __res;
+}
+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)
+{
+ register signed char __res = 0;
+
+ while (count) {
+ if ((__res = *cs - *ct++) != 0 || !*cs++)
+ break;
+ count--;
+ }
+
+ return __res;
+}
+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
+
+#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
+
+/**
+ * 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);
+
+#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, *end;
+
+ if (sbegin == NULL)
+ return NULL;
+
+ end = strpbrk(sbegin, ct);
+ if (end)
+ *end++ = '\0';
+ *s = end;
+
+ return sbegin;
+}
+
+EXPORT_SYMBOL(strsep);
+#endif
+
+#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 = (char *) 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 = (char *) dest, *s = (char *) 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, *s;
+
+ if (dest <= src) {
+ tmp = (char *) dest;
+ s = (char *) src;
+ while (count--)
+ *tmp++ = *s++;
+ }
+ else {
+ tmp = (char *) dest + count;
+ s = (char *) src + 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.
+ */
+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 = (unsigned char *) 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)
+{
+ int 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_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