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Diffstat (limited to 'lib/string.c')
| -rw-r--r-- | lib/string.c | 601 |
1 files changed, 601 insertions, 0 deletions
diff --git a/lib/string.c b/lib/string.c new file mode 100644 index 000000000000..4bb93ad23c60 --- /dev/null +++ b/lib/string.c @@ -0,0 +1,601 @@ +/* + * 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 |