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git.ipfire.org Git - people/ms/u-boot.git/blob - lib/string.c
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>
25 * strncasecmp - Case insensitive, length-limited string comparison
27 * @s2: The other string
28 * @len: the maximum number of characters to compare
30 int strncasecmp(const char *s1
, const char *s2
, size_t len
)
32 /* Yes, Virginia, it had better be unsigned */
52 return (int)c1
- (int)c2
;
56 * strcasecmp - Case insensitive string comparison
58 * @s2: The other string
60 int strcasecmp(const char *s1
, const char *s2
)
62 return strncasecmp(s1
, s2
, -1U);
67 #ifndef __HAVE_ARCH_STRCPY
69 * strcpy - Copy a %NUL terminated string
70 * @dest: Where to copy the string to
71 * @src: Where to copy the string from
73 char * strcpy(char * dest
,const char *src
)
77 while ((*dest
++ = *src
++) != '\0')
83 #ifndef __HAVE_ARCH_STRNCPY
85 * strncpy - Copy a length-limited, %NUL-terminated string
86 * @dest: Where to copy the string to
87 * @src: Where to copy the string from
88 * @count: The maximum number of bytes to copy
90 * Note that unlike userspace strncpy, this does not %NUL-pad the buffer.
91 * However, the result is not %NUL-terminated if the source exceeds
94 char * strncpy(char * dest
,const char *src
,size_t count
)
98 while (count
-- && (*dest
++ = *src
++) != '\0')
105 #ifndef __HAVE_ARCH_STRLCPY
107 * strlcpy - Copy a C-string into a sized buffer
108 * @dest: Where to copy the string to
109 * @src: Where to copy the string from
110 * @size: size of destination buffer
112 * Compatible with *BSD: the result is always a valid
113 * NUL-terminated string that fits in the buffer (unless,
114 * of course, the buffer size is zero). It does not pad
115 * out the result like strncpy() does.
117 size_t strlcpy(char *dest
, const char *src
, size_t size
)
119 size_t ret
= strlen(src
);
122 size_t len
= (ret
>= size
) ? size
- 1 : ret
;
123 memcpy(dest
, src
, len
);
130 #ifndef __HAVE_ARCH_STRCAT
132 * strcat - Append one %NUL-terminated string to another
133 * @dest: The string to be appended to
134 * @src: The string to append to it
136 char * strcat(char * dest
, const char * src
)
142 while ((*dest
++ = *src
++) != '\0')
149 #ifndef __HAVE_ARCH_STRNCAT
151 * strncat - Append a length-limited, %NUL-terminated string to another
152 * @dest: The string to be appended to
153 * @src: The string to append to it
154 * @count: The maximum numbers of bytes to copy
156 * Note that in contrast to strncpy, strncat ensures the result is
159 char * strncat(char *dest
, const char *src
, size_t count
)
166 while ((*dest
++ = *src
++)) {
178 #ifndef __HAVE_ARCH_STRCMP
180 * strcmp - Compare two strings
182 * @ct: Another string
184 int strcmp(const char * cs
,const char * ct
)
186 register signed char __res
;
189 if ((__res
= *cs
- *ct
++) != 0 || !*cs
++)
197 #ifndef __HAVE_ARCH_STRNCMP
199 * strncmp - Compare two length-limited strings
201 * @ct: Another string
202 * @count: The maximum number of bytes to compare
204 int strncmp(const char * cs
,const char * ct
,size_t count
)
206 register signed char __res
= 0;
209 if ((__res
= *cs
- *ct
++) != 0 || !*cs
++)
218 #ifndef __HAVE_ARCH_STRCHR
220 * strchr - Find the first occurrence of a character in a string
221 * @s: The string to be searched
222 * @c: The character to search for
224 char * strchr(const char * s
, int c
)
226 for(; *s
!= (char) c
; ++s
)
233 const char *strchrnul(const char *s
, int c
)
235 for (; *s
!= (char)c
; ++s
)
241 #ifndef __HAVE_ARCH_STRRCHR
243 * strrchr - Find the last occurrence of a character in a string
244 * @s: The string to be searched
245 * @c: The character to search for
247 char * strrchr(const char * s
, int c
)
249 const char *p
= s
+ strlen(s
);
258 #ifndef __HAVE_ARCH_STRLEN
260 * strlen - Find the length of a string
261 * @s: The string to be sized
263 size_t strlen(const char * s
)
267 for (sc
= s
; *sc
!= '\0'; ++sc
)
273 #ifndef __HAVE_ARCH_STRNLEN
275 * strnlen - Find the length of a length-limited string
276 * @s: The string to be sized
277 * @count: The maximum number of bytes to search
279 size_t strnlen(const char * s
, size_t count
)
283 for (sc
= s
; count
-- && *sc
!= '\0'; ++sc
)
289 #ifndef __HAVE_ARCH_STRCSPN
291 * strcspn - Calculate the length of the initial substring of @s which does
292 * not contain letters in @reject
293 * @s: The string to be searched
294 * @reject: The string to avoid
296 size_t strcspn(const char *s
, const char *reject
)
302 for (p
= s
; *p
!= '\0'; ++p
) {
303 for (r
= reject
; *r
!= '\0'; ++r
) {
313 #ifndef __HAVE_ARCH_STRDUP
314 char * strdup(const char *s
)
319 ((new = malloc (strlen(s
) + 1)) == NULL
) ) {
328 #ifndef __HAVE_ARCH_STRSPN
330 * strspn - Calculate the length of the initial substring of @s which only
331 * contain letters in @accept
332 * @s: The string to be searched
333 * @accept: The string to search for
335 size_t strspn(const char *s
, const char *accept
)
341 for (p
= s
; *p
!= '\0'; ++p
) {
342 for (a
= accept
; *a
!= '\0'; ++a
) {
355 #ifndef __HAVE_ARCH_STRPBRK
357 * strpbrk - Find the first occurrence of a set of characters
358 * @cs: The string to be searched
359 * @ct: The characters to search for
361 char * strpbrk(const char * cs
,const char * ct
)
363 const char *sc1
,*sc2
;
365 for( sc1
= cs
; *sc1
!= '\0'; ++sc1
) {
366 for( sc2
= ct
; *sc2
!= '\0'; ++sc2
) {
375 #ifndef __HAVE_ARCH_STRTOK
377 * strtok - Split a string into tokens
378 * @s: The string to be searched
379 * @ct: The characters to search for
381 * WARNING: strtok is deprecated, use strsep instead.
383 char * strtok(char * s
,const char * ct
)
387 sbegin
= s
? s
: ___strtok
;
391 sbegin
+= strspn(sbegin
,ct
);
392 if (*sbegin
== '\0') {
396 send
= strpbrk( sbegin
, ct
);
397 if (send
&& *send
!= '\0')
404 #ifndef __HAVE_ARCH_STRSEP
406 * strsep - Split a string into tokens
407 * @s: The string to be searched
408 * @ct: The characters to search for
410 * strsep() updates @s to point after the token, ready for the next call.
412 * It returns empty tokens, too, behaving exactly like the libc function
413 * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
414 * Same semantics, slimmer shape. ;)
416 char * strsep(char **s
, const char *ct
)
418 char *sbegin
= *s
, *end
;
423 end
= strpbrk(sbegin
, ct
);
432 #ifndef __HAVE_ARCH_STRSWAB
434 * strswab - swap adjacent even and odd bytes in %NUL-terminated string
435 * s: address of the string
437 * returns the address of the swapped string or NULL on error. If
438 * string length is odd, last byte is untouched.
440 char *strswab(const char *s
)
444 if ((NULL
== s
) || ('\0' == *s
)) {
448 for (p
=(char *)s
, q
=p
+1; (*p
!= '\0') && (*q
!= '\0'); p
+=2, q
+=2) {
460 #ifndef __HAVE_ARCH_MEMSET
462 * memset - Fill a region of memory with the given value
463 * @s: Pointer to the start of the area.
464 * @c: The byte to fill the area with
465 * @count: The size of the area.
467 * Do not use memset() to access IO space, use memset_io() instead.
469 void * memset(void * s
,int c
,size_t count
)
471 unsigned long *sl
= (unsigned long *) s
;
474 #if !CONFIG_IS_ENABLED(TINY_MEMSET)
475 unsigned long cl
= 0;
478 /* do it one word at a time (32 bits or 64 bits) while possible */
479 if ( ((ulong
)s
& (sizeof(*sl
) - 1)) == 0) {
480 for (i
= 0; i
< sizeof(*sl
); i
++) {
484 while (count
>= sizeof(*sl
)) {
486 count
-= sizeof(*sl
);
489 #endif /* fill 8 bits at a time */
498 #ifndef __HAVE_ARCH_MEMCPY
500 * memcpy - Copy one area of memory to another
501 * @dest: Where to copy to
502 * @src: Where to copy from
503 * @count: The size of the area.
505 * You should not use this function to access IO space, use memcpy_toio()
506 * or memcpy_fromio() instead.
508 void * memcpy(void *dest
, const void *src
, size_t count
)
510 unsigned long *dl
= (unsigned long *)dest
, *sl
= (unsigned long *)src
;
516 /* while all data is aligned (common case), copy a word at a time */
517 if ( (((ulong
)dest
| (ulong
)src
) & (sizeof(*dl
) - 1)) == 0) {
518 while (count
>= sizeof(*dl
)) {
520 count
-= sizeof(*dl
);
523 /* copy the reset one byte at a time */
533 #ifndef __HAVE_ARCH_MEMMOVE
535 * memmove - Copy one area of memory to another
536 * @dest: Where to copy to
537 * @src: Where to copy from
538 * @count: The size of the area.
540 * Unlike memcpy(), memmove() copes with overlapping areas.
542 void * memmove(void * dest
,const void *src
,size_t count
)
547 memcpy(dest
, src
, count
);
549 tmp
= (char *) dest
+ count
;
550 s
= (char *) src
+ count
;
559 #ifndef __HAVE_ARCH_MEMCMP
561 * memcmp - Compare two areas of memory
562 * @cs: One area of memory
563 * @ct: Another area of memory
564 * @count: The size of the area.
566 int memcmp(const void * cs
,const void * ct
,size_t count
)
568 const unsigned char *su1
, *su2
;
571 for( su1
= cs
, su2
= ct
; 0 < count
; ++su1
, ++su2
, count
--)
572 if ((res
= *su1
- *su2
) != 0)
578 #ifndef __HAVE_ARCH_MEMSCAN
580 * memscan - Find a character in an area of memory.
581 * @addr: The memory area
582 * @c: The byte to search for
583 * @size: The size of the area.
585 * returns the address of the first occurrence of @c, or 1 byte past
586 * the area if @c is not found
588 void * memscan(void * addr
, int c
, size_t size
)
590 unsigned char * p
= (unsigned char *) addr
;
602 #ifndef __HAVE_ARCH_STRSTR
604 * strstr - Find the first substring in a %NUL terminated string
605 * @s1: The string to be searched
606 * @s2: The string to search for
608 char * strstr(const char * s1
,const char * s2
)
618 if (!memcmp(s1
,s2
,l2
))
626 #ifndef __HAVE_ARCH_MEMCHR
628 * memchr - Find a character in an area of memory.
629 * @s: The memory area
630 * @c: The byte to search for
631 * @n: The size of the area.
633 * returns the address of the first occurrence of @c, or %NULL
636 void *memchr(const void *s
, int c
, size_t n
)
638 const unsigned char *p
= s
;
640 if ((unsigned char)c
== *p
++) {
641 return (void *)(p
-1);
648 #ifndef __HAVE_ARCH_MEMCHR_INV
649 static void *check_bytes8(const u8
*start
, u8 value
, unsigned int bytes
)
653 return (void *)start
;
660 * memchr_inv - Find an unmatching character in an area of memory.
661 * @start: The memory area
662 * @c: Find a character other than c
663 * @bytes: The size of the area.
665 * returns the address of the first character other than @c, or %NULL
666 * if the whole buffer contains just @c.
668 void *memchr_inv(const void *start
, int c
, size_t bytes
)
672 unsigned int words
, prefix
;
675 return check_bytes8(start
, value
, bytes
);
678 value64
|= value64
<< 8;
679 value64
|= value64
<< 16;
680 value64
|= value64
<< 32;
682 prefix
= (unsigned long)start
% 8;
687 r
= check_bytes8(start
, value
, prefix
);
697 if (*(u64
*)start
!= value64
)
698 return check_bytes8(start
, value
, 8);
703 return check_bytes8(start
, value
, bytes
% 8);