4 * Copyright (C) 1991, 1992 Linus Torvalds
8 * stupid library routines.. The optimized versions should generally be found
9 * as inline code in <asm-xx/string.h>
11 * These are buggy as well..
13 * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de>
14 * - Added strsep() which will replace strtok() soon (because strsep() is
15 * reentrant and should be faster). Use only strsep() in new code, please.
18 #include <linux/types.h>
19 #include <linux/string.h>
20 #include <linux/ctype.h>
24 #if 0 /* not used - was: #ifndef __HAVE_ARCH_STRNICMP */
26 * strnicmp - Case insensitive, length-limited string comparison
28 * @s2: The other string
29 * @len: the maximum number of characters to compare
31 int strnicmp(const char *s1, const char *s2, size_t len)
33 /* Yes, Virginia, it had better be unsigned */
53 return (int)c1 - (int)c2;
59 #ifndef __HAVE_ARCH_STRCPY
61 * strcpy - Copy a %NUL terminated string
62 * @dest: Where to copy the string to
63 * @src: Where to copy the string from
65 char * strcpy(char * dest,const char *src)
69 while ((*dest++ = *src++) != '\0')
75 #ifndef __HAVE_ARCH_STRNCPY
77 * strncpy - Copy a length-limited, %NUL-terminated string
78 * @dest: Where to copy the string to
79 * @src: Where to copy the string from
80 * @count: The maximum number of bytes to copy
82 * Note that unlike userspace strncpy, this does not %NUL-pad the buffer.
83 * However, the result is not %NUL-terminated if the source exceeds
86 char * strncpy(char * dest,const char *src,size_t count)
90 while (count-- && (*dest++ = *src++) != '\0')
97 #ifndef __HAVE_ARCH_STRCAT
99 * strcat - Append one %NUL-terminated string to another
100 * @dest: The string to be appended to
101 * @src: The string to append to it
103 char * strcat(char * dest, const char * src)
109 while ((*dest++ = *src++) != '\0')
116 #ifndef __HAVE_ARCH_STRNCAT
118 * strncat - Append a length-limited, %NUL-terminated string to another
119 * @dest: The string to be appended to
120 * @src: The string to append to it
121 * @count: The maximum numbers of bytes to copy
123 * Note that in contrast to strncpy, strncat ensures the result is
126 char * strncat(char *dest, const char *src, size_t count)
133 while ((*dest++ = *src++)) {
145 #ifndef __HAVE_ARCH_STRCMP
147 * strcmp - Compare two strings
149 * @ct: Another string
151 int strcmp(const char * cs,const char * ct)
153 register signed char __res;
156 if ((__res = *cs - *ct++) != 0 || !*cs++)
164 #ifndef __HAVE_ARCH_STRNCMP
166 * strncmp - Compare two length-limited strings
168 * @ct: Another string
169 * @count: The maximum number of bytes to compare
171 int strncmp(const char * cs,const char * ct,size_t count)
173 register signed char __res = 0;
176 if ((__res = *cs - *ct++) != 0 || !*cs++)
185 #ifndef __HAVE_ARCH_STRCHR
187 * strchr - Find the first occurrence of a character in a string
188 * @s: The string to be searched
189 * @c: The character to search for
191 char * strchr(const char * s, int c)
193 for(; *s != (char) c; ++s)
200 #ifndef __HAVE_ARCH_STRRCHR
202 * strrchr - Find the last occurrence of a character in a string
203 * @s: The string to be searched
204 * @c: The character to search for
206 char * strrchr(const char * s, int c)
208 const char *p = s + strlen(s);
219 * skip_spaces - Removes leading whitespace from @str.
220 * @str: The string to be stripped.
222 * Returns a pointer to the first non-whitespace character in @str.
224 char *skip_spaces(const char *str)
226 while (isspace(*str))
232 * strim - Removes leading and trailing whitespace from @s.
233 * @s: The string to be stripped.
235 * Note that the first trailing whitespace is replaced with a %NUL-terminator
236 * in the given string @s. Returns a pointer to the first non-whitespace
250 while (end >= s && isspace(*end))
256 #ifndef __HAVE_ARCH_STRLEN
258 * strlen - Find the length of a string
259 * @s: The string to be sized
261 size_t strlen(const char * s)
265 for (sc = s; *sc != '\0'; ++sc)
271 #ifndef __HAVE_ARCH_STRNLEN
273 * strnlen - Find the length of a length-limited string
274 * @s: The string to be sized
275 * @count: The maximum number of bytes to search
277 size_t strnlen(const char * s, size_t count)
281 for (sc = s; count-- && *sc != '\0'; ++sc)
287 #ifndef __HAVE_ARCH_STRDUP
288 char * strdup(const char *s)
293 ((new = malloc (strlen(s) + 1)) == NULL) ) {
302 #ifndef __HAVE_ARCH_STRSPN
304 * strspn - Calculate the length of the initial substring of @s which only
305 * contain letters in @accept
306 * @s: The string to be searched
307 * @accept: The string to search for
309 size_t strspn(const char *s, const char *accept)
315 for (p = s; *p != '\0'; ++p) {
316 for (a = accept; *a != '\0'; ++a) {
329 #ifndef __HAVE_ARCH_STRPBRK
331 * strpbrk - Find the first occurrence of a set of characters
332 * @cs: The string to be searched
333 * @ct: The characters to search for
335 char * strpbrk(const char * cs,const char * ct)
337 const char *sc1,*sc2;
339 for( sc1 = cs; *sc1 != '\0'; ++sc1) {
340 for( sc2 = ct; *sc2 != '\0'; ++sc2) {
349 #ifndef __HAVE_ARCH_STRTOK
351 * strtok - Split a string into tokens
352 * @s: The string to be searched
353 * @ct: The characters to search for
355 * WARNING: strtok is deprecated, use strsep instead.
357 char * strtok(char * s,const char * ct)
361 sbegin = s ? s : ___strtok;
365 sbegin += strspn(sbegin,ct);
366 if (*sbegin == '\0') {
370 send = strpbrk( sbegin, ct);
371 if (send && *send != '\0')
378 #ifndef __HAVE_ARCH_STRSEP
380 * strsep - Split a string into tokens
381 * @s: The string to be searched
382 * @ct: The characters to search for
384 * strsep() updates @s to point after the token, ready for the next call.
386 * It returns empty tokens, too, behaving exactly like the libc function
387 * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
388 * Same semantics, slimmer shape. ;)
390 char * strsep(char **s, const char *ct)
392 char *sbegin = *s, *end;
397 end = strpbrk(sbegin, ct);
406 #ifndef __HAVE_ARCH_STRSWAB
408 * strswab - swap adjacent even and odd bytes in %NUL-terminated string
409 * s: address of the string
411 * returns the address of the swapped string or NULL on error. If
412 * string length is odd, last byte is untouched.
414 char *strswab(const char *s)
418 if ((NULL == s) || ('\0' == *s)) {
422 for (p=(char *)s, q=p+1; (*p != '\0') && (*q != '\0'); p+=2, q+=2) {
434 #ifndef __HAVE_ARCH_MEMSET
436 * memset - Fill a region of memory with the given value
437 * @s: Pointer to the start of the area.
438 * @c: The byte to fill the area with
439 * @count: The size of the area.
441 * Do not use memset() to access IO space, use memset_io() instead.
443 void * memset(void * s,int c,size_t count)
445 unsigned long *sl = (unsigned long *) s;
446 unsigned long cl = 0;
450 /* do it one word at a time (32 bits or 64 bits) while possible */
451 if ( ((ulong)s & (sizeof(*sl) - 1)) == 0) {
452 for (i = 0; i < sizeof(*sl); i++) {
456 while (count >= sizeof(*sl)) {
458 count -= sizeof(*sl);
461 /* fill 8 bits at a time */
470 #ifndef __HAVE_ARCH_BCOPY
472 * bcopy - Copy one area of memory to another
473 * @src: Where to copy from
474 * @dest: Where to copy to
475 * @count: The size of the area.
477 * Note that this is the same as memcpy(), with the arguments reversed.
478 * memcpy() is the standard, bcopy() is a legacy BSD function.
480 * You should not use this function to access IO space, use memcpy_toio()
481 * or memcpy_fromio() instead.
483 char * bcopy(const char * src, char * dest, int count)
494 #ifndef __HAVE_ARCH_MEMCPY
496 * memcpy - Copy one area of memory to another
497 * @dest: Where to copy to
498 * @src: Where to copy from
499 * @count: The size of the area.
501 * You should not use this function to access IO space, use memcpy_toio()
502 * or memcpy_fromio() instead.
504 void * memcpy(void *dest, const void *src, size_t count)
506 unsigned long *dl = (unsigned long *)dest, *sl = (unsigned long *)src;
512 /* while all data is aligned (common case), copy a word at a time */
513 if ( (((ulong)dest | (ulong)src) & (sizeof(*dl) - 1)) == 0) {
514 while (count >= sizeof(*dl)) {
516 count -= sizeof(*dl);
519 /* copy the reset one byte at a time */
529 #ifndef __HAVE_ARCH_MEMMOVE
531 * memmove - Copy one area of memory to another
532 * @dest: Where to copy to
533 * @src: Where to copy from
534 * @count: The size of the area.
536 * Unlike memcpy(), memmove() copes with overlapping areas.
538 void * memmove(void * dest,const void *src,size_t count)
552 tmp = (char *) dest + count;
553 s = (char *) src + count;
562 #ifndef __HAVE_ARCH_MEMCMP
564 * memcmp - Compare two areas of memory
565 * @cs: One area of memory
566 * @ct: Another area of memory
567 * @count: The size of the area.
569 int memcmp(const void * cs,const void * ct,size_t count)
571 const unsigned char *su1, *su2;
574 for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
575 if ((res = *su1 - *su2) != 0)
581 #ifndef __HAVE_ARCH_MEMSCAN
583 * memscan - Find a character in an area of memory.
584 * @addr: The memory area
585 * @c: The byte to search for
586 * @size: The size of the area.
588 * returns the address of the first occurrence of @c, or 1 byte past
589 * the area if @c is not found
591 void * memscan(void * addr, int c, size_t size)
593 unsigned char * p = (unsigned char *) addr;
605 #ifndef __HAVE_ARCH_STRSTR
607 * strstr - Find the first substring in a %NUL terminated string
608 * @s1: The string to be searched
609 * @s2: The string to search for
611 char * strstr(const char * s1,const char * s2)
621 if (!memcmp(s1,s2,l2))
629 #ifndef __HAVE_ARCH_MEMCHR
631 * memchr - Find a character in an area of memory.
632 * @s: The memory area
633 * @c: The byte to search for
634 * @n: The size of the area.
636 * returns the address of the first occurrence of @c, or %NULL
639 void *memchr(const void *s, int c, size_t n)
641 const unsigned char *p = s;
643 if ((unsigned char)c == *p++) {
644 return (void *)(p-1);