/* * 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. */ #include <linux/types.h> #include <linux/string.h> #include <linux/ctype.h> #include <malloc.h> /** * 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; 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; } /** * strcasecmp - Case insensitive string comparison * @s1: One string * @s2: The other string */ int strcasecmp(const char *s1, const char *s2) { return strncasecmp(s1, s2, -1U); } char * ___strtok; #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; } #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 * * Note that unlike userspace strncpy, this does not %NUL-pad the buffer. * However, 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-- && (*dest++ = *src++) != '\0') /* nothing */; return tmp; } #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; } #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++)) { if (--count == 0) { *dest = '\0'; break; } } } return tmp; } #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; } #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; } #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; } #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; } #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; } #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; } #endif #ifndef __HAVE_ARCH_STRDUP char * strdup(const char *s) { char *new; if ((s == NULL) || ((new = malloc (strlen(s) + 1)) == NULL) ) { return NULL; } strcpy (new, s); return new; } #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; } #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; } #endif #ifndef __HAVE_ARCH_STRTOK /** * strtok - Split a string into tokens * @s: The string to be searched * @ct: The characters to search for * * WARNING: strtok is deprecated, use strsep instead. */ char * strtok(char * s,const char * ct) { char *sbegin, *send; sbegin = s ? s : ___strtok; if (!sbegin) { return NULL; } sbegin += strspn(sbegin,ct); if (*sbegin == '\0') { ___strtok = NULL; return( NULL ); } send = strpbrk( sbegin, ct); if (send && *send != '\0') *send++ = '\0'; ___strtok = send; return (sbegin); } #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; } #endif #ifndef __HAVE_ARCH_STRSWAB /** * strswab - swap adjacent even and odd bytes in %NUL-terminated string * s: address of the string * * returns the address of the swapped string or NULL on error. If * string length is odd, last byte is untouched. */ char *strswab(const char *s) { char *p, *q; if ((NULL == s) || ('\0' == *s)) { return (NULL); } for (p=(char *)s, q=p+1; (*p != '\0') && (*q != '\0'); p+=2, q+=2) { char tmp; tmp = *p; *p = *q; *q = tmp; } return (char *) s; } #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) { unsigned long *sl = (unsigned long *) s; unsigned long cl = 0; char *s8; int i; /* do it one word at a time (32 bits or 64 bits) while possible */ if ( ((ulong)s & (sizeof(*sl) - 1)) == 0) { for (i = 0; i < sizeof(*sl); i++) { cl <<= 8; cl |= c & 0xff; } while (count >= sizeof(*sl)) { *sl++ = cl; count -= sizeof(*sl); } } /* fill 8 bits at a time */ s8 = (char *)sl; while (count--) *s8++ = c; return s; } #endif #ifndef __HAVE_ARCH_BCOPY /** * bcopy - Copy one area of memory to another * @src: Where to copy from * @dest: Where to copy to * @count: The size of the area. * * Note that this is the same as memcpy(), with the arguments reversed. * memcpy() is the standard, bcopy() is a legacy BSD function. * * You should not use this function to access IO space, use memcpy_toio() * or memcpy_fromio() instead. */ char * bcopy(const char * src, char * dest, int count) { char *tmp = dest; while (count--) *tmp++ = *src++; return dest; } #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) { unsigned long *dl = (unsigned long *)dest, *sl = (unsigned long *)src; char *d8, *s8; if (src == dest) return dest; /* while all data is aligned (common case), copy a word at a time */ if ( (((ulong)dest | (ulong)src) & (sizeof(*dl) - 1)) == 0) { while (count >= sizeof(*dl)) { *dl++ = *sl++; count -= sizeof(*dl); } } /* copy the reset one byte at a time */ d8 = (char *)dl; s8 = (char *)sl; while (count--) *d8++ = *s8++; return dest; } #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 (src == dest) return dest; 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; } #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; } #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; } #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; } #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; } #endif #ifndef __HAVE_ARCH_MEMCHR_INV static void *check_bytes8(const u8 *start, u8 value, unsigned int bytes) { while (bytes) { if (*start != value) return (void *)start; start++; bytes--; } return NULL; } /** * memchr_inv - Find an unmatching character in an area of memory. * @start: The memory area * @c: Find a character other than c * @bytes: The size of the area. * * returns the address of the first character other than @c, or %NULL * if the whole buffer contains just @c. */ void *memchr_inv(const void *start, int c, size_t bytes) { u8 value = c; u64 value64; unsigned int words, prefix; if (bytes <= 16) return check_bytes8(start, value, bytes); value64 = value; value64 |= value64 << 8; value64 |= value64 << 16; value64 |= value64 << 32; prefix = (unsigned long)start % 8; if (prefix) { u8 *r; prefix = 8 - prefix; r = check_bytes8(start, value, prefix); if (r) return r; start += prefix; bytes -= prefix; } words = bytes / 8; while (words) { if (*(u64 *)start != value64) return check_bytes8(start, value, 8); start += 8; words--; } return check_bytes8(start, value, bytes % 8); } #endif