blob: 63077267367ea08d7770e59a9e6e6b23bb4725e7 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/lib/string.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
7/*
8 * stupid library routines.. The optimized versions should generally be found
9 * as inline code in <asm-xx/string.h>
10 *
11 * These are buggy as well..
12 *
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.
16 *
17 * * Sat Feb 09 2002, Jason Thomas <jason@topic.com.au>,
18 * Matthew Hawkins <matt@mh.dropbear.id.au>
19 * - Kissed strtok() goodbye
20 */
21
22#include <linux/types.h>
23#include <linux/string.h>
24#include <linux/ctype.h>
25#include <linux/module.h>
26
27#ifndef __HAVE_ARCH_STRNICMP
28/**
29 * strnicmp - Case insensitive, length-limited string comparison
30 * @s1: One string
31 * @s2: The other string
32 * @len: the maximum number of characters to compare
33 */
34int strnicmp(const char *s1, const char *s2, size_t len)
35{
36 /* Yes, Virginia, it had better be unsigned */
37 unsigned char c1, c2;
38
Jesper Juhl850b9242005-10-30 15:02:13 -080039 c1 = c2 = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 if (len) {
41 do {
Jesper Juhl51a0f0f2005-10-30 15:02:11 -080042 c1 = *s1;
43 c2 = *s2;
44 s1++;
45 s2++;
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 if (!c1)
47 break;
48 if (!c2)
49 break;
50 if (c1 == c2)
51 continue;
52 c1 = tolower(c1);
53 c2 = tolower(c2);
54 if (c1 != c2)
55 break;
56 } while (--len);
57 }
58 return (int)c1 - (int)c2;
59}
Linus Torvalds1da177e2005-04-16 15:20:36 -070060EXPORT_SYMBOL(strnicmp);
61#endif
62
63#ifndef __HAVE_ARCH_STRCPY
64/**
65 * strcpy - Copy a %NUL terminated string
66 * @dest: Where to copy the string to
67 * @src: Where to copy the string from
68 */
Paolo 'Blaisorblade' Giarrusso0c281302005-05-05 16:15:17 -070069#undef strcpy
Jesper Juhl51a0f0f2005-10-30 15:02:11 -080070char *strcpy(char *dest, const char *src)
Linus Torvalds1da177e2005-04-16 15:20:36 -070071{
72 char *tmp = dest;
73
74 while ((*dest++ = *src++) != '\0')
75 /* nothing */;
76 return tmp;
77}
78EXPORT_SYMBOL(strcpy);
79#endif
80
81#ifndef __HAVE_ARCH_STRNCPY
82/**
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
87 *
88 * The result is not %NUL-terminated if the source exceeds
89 * @count bytes.
walter harms25279522005-05-05 16:16:20 -070090 *
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.
93 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -080095char *strncpy(char *dest, const char *src, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096{
97 char *tmp = dest;
98
99 while (count) {
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800100 if ((*tmp = *src) != 0)
101 src++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 tmp++;
103 count--;
104 }
105 return dest;
106}
107EXPORT_SYMBOL(strncpy);
108#endif
109
110#ifndef __HAVE_ARCH_STRLCPY
111/**
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
116 *
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.
121 */
122size_t strlcpy(char *dest, const char *src, size_t size)
123{
124 size_t ret = strlen(src);
125
126 if (size) {
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800127 size_t len = (ret >= size) ? size - 1 : ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 memcpy(dest, src, len);
129 dest[len] = '\0';
130 }
131 return ret;
132}
133EXPORT_SYMBOL(strlcpy);
134#endif
135
136#ifndef __HAVE_ARCH_STRCAT
137/**
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
141 */
Paolo 'Blaisorblade' Giarrusso0c281302005-05-05 16:15:17 -0700142#undef strcat
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800143char *strcat(char *dest, const char *src)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144{
145 char *tmp = dest;
146
147 while (*dest)
148 dest++;
149 while ((*dest++ = *src++) != '\0')
150 ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 return tmp;
152}
153EXPORT_SYMBOL(strcat);
154#endif
155
156#ifndef __HAVE_ARCH_STRNCAT
157/**
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
162 *
163 * Note that in contrast to strncpy, strncat ensures the result is
164 * terminated.
165 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800166char *strncat(char *dest, const char *src, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167{
168 char *tmp = dest;
169
170 if (count) {
171 while (*dest)
172 dest++;
173 while ((*dest++ = *src++) != 0) {
174 if (--count == 0) {
175 *dest = '\0';
176 break;
177 }
178 }
179 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 return tmp;
181}
182EXPORT_SYMBOL(strncat);
183#endif
184
185#ifndef __HAVE_ARCH_STRLCAT
186/**
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.
191 */
192size_t strlcat(char *dest, const char *src, size_t count)
193{
194 size_t dsize = strlen(dest);
195 size_t len = strlen(src);
196 size_t res = dsize + len;
197
198 /* This would be a bug */
199 BUG_ON(dsize >= count);
200
201 dest += dsize;
202 count -= dsize;
203 if (len >= count)
204 len = count-1;
205 memcpy(dest, src, len);
206 dest[len] = 0;
207 return res;
208}
209EXPORT_SYMBOL(strlcat);
210#endif
211
212#ifndef __HAVE_ARCH_STRCMP
213/**
214 * strcmp - Compare two strings
215 * @cs: One string
216 * @ct: Another string
217 */
Paolo 'Blaisorblade' Giarrusso0c281302005-05-05 16:15:17 -0700218#undef strcmp
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800219int strcmp(const char *cs, const char *ct)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220{
Jesper Juhlcc75fb72005-10-30 15:02:12 -0800221 signed char __res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222
223 while (1) {
224 if ((__res = *cs - *ct++) != 0 || !*cs++)
225 break;
226 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 return __res;
228}
229EXPORT_SYMBOL(strcmp);
230#endif
231
232#ifndef __HAVE_ARCH_STRNCMP
233/**
234 * strncmp - Compare two length-limited strings
235 * @cs: One string
236 * @ct: Another string
237 * @count: The maximum number of bytes to compare
238 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800239int strncmp(const char *cs, const char *ct, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240{
Jesper Juhlcc75fb72005-10-30 15:02:12 -0800241 signed char __res = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
243 while (count) {
244 if ((__res = *cs - *ct++) != 0 || !*cs++)
245 break;
246 count--;
247 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 return __res;
249}
250EXPORT_SYMBOL(strncmp);
251#endif
252
253#ifndef __HAVE_ARCH_STRCHR
254/**
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
258 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800259char *strchr(const char *s, int c)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260{
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800261 for (; *s != (char)c; ++s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 if (*s == '\0')
263 return NULL;
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800264 return (char *)s;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266EXPORT_SYMBOL(strchr);
267#endif
268
269#ifndef __HAVE_ARCH_STRRCHR
270/**
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
274 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800275char *strrchr(const char *s, int c)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276{
277 const char *p = s + strlen(s);
278 do {
279 if (*p == (char)c)
280 return (char *)p;
281 } while (--p >= s);
282 return NULL;
283}
284EXPORT_SYMBOL(strrchr);
285#endif
286
287#ifndef __HAVE_ARCH_STRNCHR
288/**
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
293 */
294char *strnchr(const char *s, size_t count, int c)
295{
296 for (; count-- && *s != '\0'; ++s)
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800297 if (*s == (char)c)
298 return (char *)s;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 return NULL;
300}
301EXPORT_SYMBOL(strnchr);
302#endif
303
Pekka Enberg481fad42006-06-23 02:05:44 -0700304/**
305 * strstrip - Removes leading and trailing whitespace from @s.
306 * @s: The string to be stripped.
307 *
308 * Note that the first trailing whitespace is replaced with a %NUL-terminator
309 * in the given string @s. Returns a pointer to the first non-whitespace
310 * character in @s.
311 */
312char *strstrip(char *s)
313{
314 size_t size;
315 char *end;
316
317 size = strlen(s);
318
319 if (!size)
320 return s;
321
322 end = s + size - 1;
323 while (end != s && isspace(*end))
324 end--;
325 *(end + 1) = '\0';
326
327 while (*s && isspace(*s))
328 s++;
329
330 return s;
331}
332EXPORT_SYMBOL(strstrip);
333
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334#ifndef __HAVE_ARCH_STRLEN
335/**
336 * strlen - Find the length of a string
337 * @s: The string to be sized
338 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800339size_t strlen(const char *s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340{
341 const char *sc;
342
343 for (sc = s; *sc != '\0'; ++sc)
344 /* nothing */;
345 return sc - s;
346}
347EXPORT_SYMBOL(strlen);
348#endif
349
350#ifndef __HAVE_ARCH_STRNLEN
351/**
352 * strnlen - Find the length of a length-limited string
353 * @s: The string to be sized
354 * @count: The maximum number of bytes to search
355 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800356size_t strnlen(const char *s, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357{
358 const char *sc;
359
360 for (sc = s; count-- && *sc != '\0'; ++sc)
361 /* nothing */;
362 return sc - s;
363}
364EXPORT_SYMBOL(strnlen);
365#endif
366
367#ifndef __HAVE_ARCH_STRSPN
368/**
369 * strspn - Calculate the length of the initial substring of @s which only
370 * contain letters in @accept
371 * @s: The string to be searched
372 * @accept: The string to search for
373 */
374size_t strspn(const char *s, const char *accept)
375{
376 const char *p;
377 const char *a;
378 size_t count = 0;
379
380 for (p = s; *p != '\0'; ++p) {
381 for (a = accept; *a != '\0'; ++a) {
382 if (*p == *a)
383 break;
384 }
385 if (*a == '\0')
386 return count;
387 ++count;
388 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389 return count;
390}
391
392EXPORT_SYMBOL(strspn);
393#endif
394
Kyle McMartin8833d322006-04-10 22:53:57 -0700395#ifndef __HAVE_ARCH_STRCSPN
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396/**
397 * strcspn - Calculate the length of the initial substring of @s which does
398 * not contain letters in @reject
399 * @s: The string to be searched
400 * @reject: The string to avoid
401 */
402size_t strcspn(const char *s, const char *reject)
403{
404 const char *p;
405 const char *r;
406 size_t count = 0;
407
408 for (p = s; *p != '\0'; ++p) {
409 for (r = reject; *r != '\0'; ++r) {
410 if (*p == *r)
411 return count;
412 }
413 ++count;
414 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 return count;
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800416}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417EXPORT_SYMBOL(strcspn);
Kyle McMartin8833d322006-04-10 22:53:57 -0700418#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
420#ifndef __HAVE_ARCH_STRPBRK
421/**
422 * strpbrk - Find the first occurrence of a set of characters
423 * @cs: The string to be searched
424 * @ct: The characters to search for
425 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800426char *strpbrk(const char *cs, const char *ct)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427{
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800428 const char *sc1, *sc2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800430 for (sc1 = cs; *sc1 != '\0'; ++sc1) {
431 for (sc2 = ct; *sc2 != '\0'; ++sc2) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 if (*sc1 == *sc2)
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800433 return (char *)sc1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 }
435 }
436 return NULL;
437}
Kyle McMartin894b5772006-04-10 22:53:56 -0700438EXPORT_SYMBOL(strpbrk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439#endif
440
441#ifndef __HAVE_ARCH_STRSEP
442/**
443 * strsep - Split a string into tokens
444 * @s: The string to be searched
445 * @ct: The characters to search for
446 *
447 * strsep() updates @s to point after the token, ready for the next call.
448 *
449 * It returns empty tokens, too, behaving exactly like the libc function
450 * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
451 * Same semantics, slimmer shape. ;)
452 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800453char *strsep(char **s, const char *ct)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454{
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800455 char *sbegin = *s;
456 char *end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457
458 if (sbegin == NULL)
459 return NULL;
460
461 end = strpbrk(sbegin, ct);
462 if (end)
463 *end++ = '\0';
464 *s = end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 return sbegin;
466}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467EXPORT_SYMBOL(strsep);
468#endif
469
470#ifndef __HAVE_ARCH_MEMSET
471/**
472 * memset - Fill a region of memory with the given value
473 * @s: Pointer to the start of the area.
474 * @c: The byte to fill the area with
475 * @count: The size of the area.
476 *
477 * Do not use memset() to access IO space, use memset_io() instead.
478 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800479void *memset(void *s, int c, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480{
Jesper Juhl850b9242005-10-30 15:02:13 -0800481 char *xs = s;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482
483 while (count--)
484 *xs++ = c;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 return s;
486}
487EXPORT_SYMBOL(memset);
488#endif
489
490#ifndef __HAVE_ARCH_MEMCPY
491/**
492 * memcpy - Copy one area of memory to another
493 * @dest: Where to copy to
494 * @src: Where to copy from
495 * @count: The size of the area.
496 *
497 * You should not use this function to access IO space, use memcpy_toio()
498 * or memcpy_fromio() instead.
499 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800500void *memcpy(void *dest, const void *src, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501{
Jesper Juhl850b9242005-10-30 15:02:13 -0800502 char *tmp = dest;
Jan-Benedict Glaw4c416ab2006-04-10 22:54:09 -0700503 const char *s = src;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
505 while (count--)
506 *tmp++ = *s++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 return dest;
508}
509EXPORT_SYMBOL(memcpy);
510#endif
511
512#ifndef __HAVE_ARCH_MEMMOVE
513/**
514 * memmove - Copy one area of memory to another
515 * @dest: Where to copy to
516 * @src: Where to copy from
517 * @count: The size of the area.
518 *
519 * Unlike memcpy(), memmove() copes with overlapping areas.
520 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800521void *memmove(void *dest, const void *src, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522{
Paul Jackson82da2c32005-10-30 15:03:19 -0800523 char *tmp;
524 const char *s;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525
526 if (dest <= src) {
Jesper Juhl850b9242005-10-30 15:02:13 -0800527 tmp = dest;
528 s = src;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 while (count--)
530 *tmp++ = *s++;
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800531 } else {
Jesper Juhl850b9242005-10-30 15:02:13 -0800532 tmp = dest;
533 tmp += count;
534 s = src;
535 s += count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 while (count--)
537 *--tmp = *--s;
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800538 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539 return dest;
540}
541EXPORT_SYMBOL(memmove);
542#endif
543
544#ifndef __HAVE_ARCH_MEMCMP
545/**
546 * memcmp - Compare two areas of memory
547 * @cs: One area of memory
548 * @ct: Another area of memory
549 * @count: The size of the area.
550 */
Paolo 'Blaisorblade' Giarrusso0c281302005-05-05 16:15:17 -0700551#undef memcmp
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800552int memcmp(const void *cs, const void *ct, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553{
554 const unsigned char *su1, *su2;
555 int res = 0;
556
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800557 for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 if ((res = *su1 - *su2) != 0)
559 break;
560 return res;
561}
562EXPORT_SYMBOL(memcmp);
563#endif
564
565#ifndef __HAVE_ARCH_MEMSCAN
566/**
567 * memscan - Find a character in an area of memory.
568 * @addr: The memory area
569 * @c: The byte to search for
570 * @size: The size of the area.
571 *
572 * returns the address of the first occurrence of @c, or 1 byte past
573 * the area if @c is not found
574 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800575void *memscan(void *addr, int c, size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576{
Jesper Juhl850b9242005-10-30 15:02:13 -0800577 unsigned char *p = addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
579 while (size) {
580 if (*p == c)
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800581 return (void *)p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 p++;
583 size--;
584 }
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800585 return (void *)p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586}
587EXPORT_SYMBOL(memscan);
588#endif
589
590#ifndef __HAVE_ARCH_STRSTR
591/**
592 * strstr - Find the first substring in a %NUL terminated string
593 * @s1: The string to be searched
594 * @s2: The string to search for
595 */
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800596char *strstr(const char *s1, const char *s2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597{
598 int l1, l2;
599
600 l2 = strlen(s2);
601 if (!l2)
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800602 return (char *)s1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 l1 = strlen(s1);
604 while (l1 >= l2) {
605 l1--;
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800606 if (!memcmp(s1, s2, l2))
607 return (char *)s1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 s1++;
609 }
610 return NULL;
611}
612EXPORT_SYMBOL(strstr);
613#endif
614
615#ifndef __HAVE_ARCH_MEMCHR
616/**
617 * memchr - Find a character in an area of memory.
618 * @s: The memory area
619 * @c: The byte to search for
620 * @n: The size of the area.
621 *
622 * returns the address of the first occurrence of @c, or %NULL
623 * if @c is not found
624 */
625void *memchr(const void *s, int c, size_t n)
626{
627 const unsigned char *p = s;
628 while (n-- != 0) {
629 if ((unsigned char)c == *p++) {
Jesper Juhl51a0f0f2005-10-30 15:02:11 -0800630 return (void *)(p - 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 }
632 }
633 return NULL;
634}
635EXPORT_SYMBOL(memchr);
636#endif