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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.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.
17 * * Sat Feb 09 2002, Jason Thomas <jason@topic.com.au>,
18 * Matthew Hawkins <matt@mh.dropbear.id.au>
19 * - Kissed strtok() goodbye
22 #include <linux/types.h>
23 #include <linux/string.h>
24 #include <linux/ctype.h>
25 #include <linux/module.h>
27 #ifndef __HAVE_ARCH_STRNICMP
29 * strnicmp - Case insensitive, length-limited string comparison
31 * @s2: The other string
32 * @len: the maximum number of characters to compare
34 int strnicmp(const char *s1
, const char *s2
, size_t len
)
36 /* Yes, Virginia, it had better be unsigned */
58 return (int)c1
- (int)c2
;
60 EXPORT_SYMBOL(strnicmp
);
63 #ifndef __HAVE_ARCH_STRCPY
65 * strcpy - Copy a %NUL terminated string
66 * @dest: Where to copy the string to
67 * @src: Where to copy the string from
70 char *strcpy(char *dest
, const char *src
)
74 while ((*dest
++ = *src
++) != '\0')
78 EXPORT_SYMBOL(strcpy
);
81 #ifndef __HAVE_ARCH_STRNCPY
83 * strncpy - Copy a length-limited, %NUL-terminated string
84 * @dest: Where to copy the string to
85 * @src: Where to copy the string from
86 * @count: The maximum number of bytes to copy
88 * The result is not %NUL-terminated if the source exceeds
91 * In the case where the length of @src is less than that of
92 * count, the remainder of @dest will be padded with %NUL.
95 char *strncpy(char *dest
, const char *src
, size_t count
)
100 if ((*tmp
= *src
) != 0)
107 EXPORT_SYMBOL(strncpy
);
110 #ifndef __HAVE_ARCH_STRLCPY
112 * strlcpy - Copy a %NUL terminated string into a sized buffer
113 * @dest: Where to copy the string to
114 * @src: Where to copy the string from
115 * @size: size of destination buffer
117 * Compatible with *BSD: the result is always a valid
118 * NUL-terminated string that fits in the buffer (unless,
119 * of course, the buffer size is zero). It does not pad
120 * out the result like strncpy() does.
122 size_t strlcpy(char *dest
, const char *src
, size_t size
)
124 size_t ret
= strlen(src
);
127 size_t len
= (ret
>= size
) ? size
- 1 : ret
;
128 memcpy(dest
, src
, len
);
133 EXPORT_SYMBOL(strlcpy
);
136 #ifndef __HAVE_ARCH_STRCAT
138 * strcat - Append one %NUL-terminated string to another
139 * @dest: The string to be appended to
140 * @src: The string to append to it
143 char *strcat(char *dest
, const char *src
)
149 while ((*dest
++ = *src
++) != '\0')
153 EXPORT_SYMBOL(strcat
);
156 #ifndef __HAVE_ARCH_STRNCAT
158 * strncat - Append a length-limited, %NUL-terminated string to another
159 * @dest: The string to be appended to
160 * @src: The string to append to it
161 * @count: The maximum numbers of bytes to copy
163 * Note that in contrast to strncpy, strncat ensures the result is
166 char *strncat(char *dest
, const char *src
, size_t count
)
173 while ((*dest
++ = *src
++) != 0) {
182 EXPORT_SYMBOL(strncat
);
185 #ifndef __HAVE_ARCH_STRLCAT
187 * strlcat - Append a length-limited, %NUL-terminated string to another
188 * @dest: The string to be appended to
189 * @src: The string to append to it
190 * @count: The size of the destination buffer.
192 size_t strlcat(char *dest
, const char *src
, size_t count
)
194 size_t dsize
= strlen(dest
);
195 size_t len
= strlen(src
);
196 size_t res
= dsize
+ len
;
198 /* This would be a bug */
199 BUG_ON(dsize
>= count
);
205 memcpy(dest
, src
, len
);
209 EXPORT_SYMBOL(strlcat
);
212 #ifndef __HAVE_ARCH_STRCMP
214 * strcmp - Compare two strings
216 * @ct: Another string
219 int strcmp(const char *cs
, const char *ct
)
224 if ((__res
= *cs
- *ct
++) != 0 || !*cs
++)
229 EXPORT_SYMBOL(strcmp
);
232 #ifndef __HAVE_ARCH_STRNCMP
234 * strncmp - Compare two length-limited strings
236 * @ct: Another string
237 * @count: The maximum number of bytes to compare
239 int strncmp(const char *cs
, const char *ct
, size_t count
)
241 signed char __res
= 0;
244 if ((__res
= *cs
- *ct
++) != 0 || !*cs
++)
250 EXPORT_SYMBOL(strncmp
);
253 #ifndef __HAVE_ARCH_STRCHR
255 * strchr - Find the first occurrence of a character in a string
256 * @s: The string to be searched
257 * @c: The character to search for
259 char *strchr(const char *s
, int c
)
261 for (; *s
!= (char)c
; ++s
)
266 EXPORT_SYMBOL(strchr
);
269 #ifndef __HAVE_ARCH_STRRCHR
271 * strrchr - Find the last occurrence of a character in a string
272 * @s: The string to be searched
273 * @c: The character to search for
275 char *strrchr(const char *s
, int c
)
277 const char *p
= s
+ strlen(s
);
284 EXPORT_SYMBOL(strrchr
);
287 #ifndef __HAVE_ARCH_STRNCHR
289 * strnchr - Find a character in a length limited string
290 * @s: The string to be searched
291 * @count: The number of characters to be searched
292 * @c: The character to search for
294 char *strnchr(const char *s
, size_t count
, int c
)
296 for (; count
-- && *s
!= '\0'; ++s
)
301 EXPORT_SYMBOL(strnchr
);
304 #ifndef __HAVE_ARCH_STRLEN
306 * strlen - Find the length of a string
307 * @s: The string to be sized
309 size_t strlen(const char *s
)
313 for (sc
= s
; *sc
!= '\0'; ++sc
)
317 EXPORT_SYMBOL(strlen
);
320 #ifndef __HAVE_ARCH_STRNLEN
322 * strnlen - Find the length of a length-limited string
323 * @s: The string to be sized
324 * @count: The maximum number of bytes to search
326 size_t strnlen(const char *s
, size_t count
)
330 for (sc
= s
; count
-- && *sc
!= '\0'; ++sc
)
334 EXPORT_SYMBOL(strnlen
);
337 #ifndef __HAVE_ARCH_STRSPN
339 * strspn - Calculate the length of the initial substring of @s which only
340 * contain letters in @accept
341 * @s: The string to be searched
342 * @accept: The string to search for
344 size_t strspn(const char *s
, const char *accept
)
350 for (p
= s
; *p
!= '\0'; ++p
) {
351 for (a
= accept
; *a
!= '\0'; ++a
) {
362 EXPORT_SYMBOL(strspn
);
365 #ifndef __HAVE_ARCH_STRCSPN
367 * strcspn - Calculate the length of the initial substring of @s which does
368 * not contain letters in @reject
369 * @s: The string to be searched
370 * @reject: The string to avoid
372 size_t strcspn(const char *s
, const char *reject
)
378 for (p
= s
; *p
!= '\0'; ++p
) {
379 for (r
= reject
; *r
!= '\0'; ++r
) {
387 EXPORT_SYMBOL(strcspn
);
390 #ifndef __HAVE_ARCH_STRPBRK
392 * strpbrk - Find the first occurrence of a set of characters
393 * @cs: The string to be searched
394 * @ct: The characters to search for
396 char *strpbrk(const char *cs
, const char *ct
)
398 const char *sc1
, *sc2
;
400 for (sc1
= cs
; *sc1
!= '\0'; ++sc1
) {
401 for (sc2
= ct
; *sc2
!= '\0'; ++sc2
) {
408 EXPORT_SYMBOL(strpbrk
);
411 #ifndef __HAVE_ARCH_STRSEP
413 * strsep - Split a string into tokens
414 * @s: The string to be searched
415 * @ct: The characters to search for
417 * strsep() updates @s to point after the token, ready for the next call.
419 * It returns empty tokens, too, behaving exactly like the libc function
420 * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
421 * Same semantics, slimmer shape. ;)
423 char *strsep(char **s
, const char *ct
)
431 end
= strpbrk(sbegin
, ct
);
437 EXPORT_SYMBOL(strsep
);
440 #ifndef __HAVE_ARCH_MEMSET
442 * memset - Fill a region of memory with the given value
443 * @s: Pointer to the start of the area.
444 * @c: The byte to fill the area with
445 * @count: The size of the area.
447 * Do not use memset() to access IO space, use memset_io() instead.
449 void *memset(void *s
, int c
, size_t count
)
457 EXPORT_SYMBOL(memset
);
460 #ifndef __HAVE_ARCH_MEMCPY
462 * memcpy - Copy one area of memory to another
463 * @dest: Where to copy to
464 * @src: Where to copy from
465 * @count: The size of the area.
467 * You should not use this function to access IO space, use memcpy_toio()
468 * or memcpy_fromio() instead.
470 void *memcpy(void *dest
, const void *src
, size_t count
)
479 EXPORT_SYMBOL(memcpy
);
482 #ifndef __HAVE_ARCH_MEMMOVE
484 * memmove - Copy one area of memory to another
485 * @dest: Where to copy to
486 * @src: Where to copy from
487 * @count: The size of the area.
489 * Unlike memcpy(), memmove() copes with overlapping areas.
491 void *memmove(void *dest
, const void *src
, size_t count
)
511 EXPORT_SYMBOL(memmove
);
514 #ifndef __HAVE_ARCH_MEMCMP
516 * memcmp - Compare two areas of memory
517 * @cs: One area of memory
518 * @ct: Another area of memory
519 * @count: The size of the area.
522 int memcmp(const void *cs
, const void *ct
, size_t count
)
524 const unsigned char *su1
, *su2
;
527 for (su1
= cs
, su2
= ct
; 0 < count
; ++su1
, ++su2
, count
--)
528 if ((res
= *su1
- *su2
) != 0)
532 EXPORT_SYMBOL(memcmp
);
535 #ifndef __HAVE_ARCH_MEMSCAN
537 * memscan - Find a character in an area of memory.
538 * @addr: The memory area
539 * @c: The byte to search for
540 * @size: The size of the area.
542 * returns the address of the first occurrence of @c, or 1 byte past
543 * the area if @c is not found
545 void *memscan(void *addr
, int c
, size_t size
)
547 unsigned char *p
= addr
;
557 EXPORT_SYMBOL(memscan
);
560 #ifndef __HAVE_ARCH_STRSTR
562 * strstr - Find the first substring in a %NUL terminated string
563 * @s1: The string to be searched
564 * @s2: The string to search for
566 char *strstr(const char *s1
, const char *s2
)
576 if (!memcmp(s1
, s2
, l2
))
582 EXPORT_SYMBOL(strstr
);
585 #ifndef __HAVE_ARCH_MEMCHR
587 * memchr - Find a character in an area of memory.
588 * @s: The memory area
589 * @c: The byte to search for
590 * @n: The size of the area.
592 * returns the address of the first occurrence of @c, or %NULL
595 void *memchr(const void *s
, int c
, size_t n
)
597 const unsigned char *p
= s
;
599 if ((unsigned char)c
== *p
++) {
600 return (void *)(p
- 1);
605 EXPORT_SYMBOL(memchr
);