/* * 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 */#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, %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 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, %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 strcmpint 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. */#undef memcmpint 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
