ia64/linux-2.6.18-xen.hg

view lib/string.c @ 782:9ab1c319531f

merge with linux-2.6.18-xen.hg
author Isaku Yamahata <yamahata@valinux.co.jp>
date Wed Jan 28 13:07:23 2009 +0900 (2009-01-28)
parents 831230e53067
children
line source
1 /*
2 * linux/lib/string.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
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 */
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
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 */
34 int strnicmp(const char *s1, const char *s2, size_t len)
35 {
36 /* Yes, Virginia, it had better be unsigned */
37 unsigned char c1, c2;
39 c1 = c2 = 0;
40 if (len) {
41 do {
42 c1 = *s1;
43 c2 = *s2;
44 s1++;
45 s2++;
46 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 }
60 EXPORT_SYMBOL(strnicmp);
61 #endif
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 */
69 #undef strcpy
70 char *strcpy(char *dest, const char *src)
71 {
72 char *tmp = dest;
74 while ((*dest++ = *src++) != '\0')
75 /* nothing */;
76 return tmp;
77 }
78 EXPORT_SYMBOL(strcpy);
79 #endif
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.
90 *
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 *
94 */
95 char *strncpy(char *dest, const char *src, size_t count)
96 {
97 char *tmp = dest;
99 while (count) {
100 if ((*tmp = *src) != 0)
101 src++;
102 tmp++;
103 count--;
104 }
105 return dest;
106 }
107 EXPORT_SYMBOL(strncpy);
108 #endif
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 */
122 size_t strlcpy(char *dest, const char *src, size_t size)
123 {
124 size_t ret = strlen(src);
126 if (size) {
127 size_t len = (ret >= size) ? size - 1 : ret;
128 memcpy(dest, src, len);
129 dest[len] = '\0';
130 }
131 return ret;
132 }
133 EXPORT_SYMBOL(strlcpy);
134 #endif
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 */
142 #undef strcat
143 char *strcat(char *dest, const char *src)
144 {
145 char *tmp = dest;
147 while (*dest)
148 dest++;
149 while ((*dest++ = *src++) != '\0')
150 ;
151 return tmp;
152 }
153 EXPORT_SYMBOL(strcat);
154 #endif
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 */
166 char *strncat(char *dest, const char *src, size_t count)
167 {
168 char *tmp = dest;
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 }
180 return tmp;
181 }
182 EXPORT_SYMBOL(strncat);
183 #endif
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 */
192 size_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;
198 /* This would be a bug */
199 BUG_ON(dsize >= count);
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 }
209 EXPORT_SYMBOL(strlcat);
210 #endif
212 #ifndef __HAVE_ARCH_STRCMP
213 /**
214 * strcmp - Compare two strings
215 * @cs: One string
216 * @ct: Another string
217 */
218 #undef strcmp
219 int strcmp(const char *cs, const char *ct)
220 {
221 signed char __res;
223 while (1) {
224 if ((__res = *cs - *ct++) != 0 || !*cs++)
225 break;
226 }
227 return __res;
228 }
229 EXPORT_SYMBOL(strcmp);
230 #endif
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 */
239 int strncmp(const char *cs, const char *ct, size_t count)
240 {
241 signed char __res = 0;
243 while (count) {
244 if ((__res = *cs - *ct++) != 0 || !*cs++)
245 break;
246 count--;
247 }
248 return __res;
249 }
250 EXPORT_SYMBOL(strncmp);
251 #endif
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 */
259 char *strchr(const char *s, int c)
260 {
261 for (; *s != (char)c; ++s)
262 if (*s == '\0')
263 return NULL;
264 return (char *)s;
265 }
266 EXPORT_SYMBOL(strchr);
267 #endif
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 */
275 char *strrchr(const char *s, int c)
276 {
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 }
284 EXPORT_SYMBOL(strrchr);
285 #endif
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 */
294 char *strnchr(const char *s, size_t count, int c)
295 {
296 for (; count-- && *s != '\0'; ++s)
297 if (*s == (char)c)
298 return (char *)s;
299 return NULL;
300 }
301 EXPORT_SYMBOL(strnchr);
302 #endif
304 /**
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 */
312 char *strstrip(char *s)
313 {
314 size_t size;
315 char *end;
317 size = strlen(s);
319 if (!size)
320 return s;
322 end = s + size - 1;
323 while (end != s && isspace(*end))
324 end--;
325 *(end + 1) = '\0';
327 while (*s && isspace(*s))
328 s++;
330 return s;
331 }
332 EXPORT_SYMBOL(strstrip);
334 #ifndef __HAVE_ARCH_STRLEN
335 /**
336 * strlen - Find the length of a string
337 * @s: The string to be sized
338 */
339 size_t strlen(const char *s)
340 {
341 const char *sc;
343 for (sc = s; *sc != '\0'; ++sc)
344 /* nothing */;
345 return sc - s;
346 }
347 EXPORT_SYMBOL(strlen);
348 #endif
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 */
356 size_t strnlen(const char *s, size_t count)
357 {
358 const char *sc;
360 for (sc = s; count-- && *sc != '\0'; ++sc)
361 /* nothing */;
362 return sc - s;
363 }
364 EXPORT_SYMBOL(strnlen);
365 #endif
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 */
374 size_t strspn(const char *s, const char *accept)
375 {
376 const char *p;
377 const char *a;
378 size_t count = 0;
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 }
389 return count;
390 }
392 EXPORT_SYMBOL(strspn);
393 #endif
395 #ifndef __HAVE_ARCH_STRCSPN
396 /**
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 */
402 size_t strcspn(const char *s, const char *reject)
403 {
404 const char *p;
405 const char *r;
406 size_t count = 0;
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 }
415 return count;
416 }
417 EXPORT_SYMBOL(strcspn);
418 #endif
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 */
426 char *strpbrk(const char *cs, const char *ct)
427 {
428 const char *sc1, *sc2;
430 for (sc1 = cs; *sc1 != '\0'; ++sc1) {
431 for (sc2 = ct; *sc2 != '\0'; ++sc2) {
432 if (*sc1 == *sc2)
433 return (char *)sc1;
434 }
435 }
436 return NULL;
437 }
438 EXPORT_SYMBOL(strpbrk);
439 #endif
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 */
453 char *strsep(char **s, const char *ct)
454 {
455 char *sbegin = *s;
456 char *end;
458 if (sbegin == NULL)
459 return NULL;
461 end = strpbrk(sbegin, ct);
462 if (end)
463 *end++ = '\0';
464 *s = end;
465 return sbegin;
466 }
467 EXPORT_SYMBOL(strsep);
468 #endif
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 */
479 void *memset(void *s, int c, size_t count)
480 {
481 char *xs = s;
483 while (count--)
484 *xs++ = c;
485 return s;
486 }
487 EXPORT_SYMBOL(memset);
488 #endif
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 */
500 void *memcpy(void *dest, const void *src, size_t count)
501 {
502 char *tmp = dest;
503 const char *s = src;
505 while (count--)
506 *tmp++ = *s++;
507 return dest;
508 }
509 EXPORT_SYMBOL(memcpy);
510 #endif
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 */
521 void *memmove(void *dest, const void *src, size_t count)
522 {
523 char *tmp;
524 const char *s;
526 if (dest <= src) {
527 tmp = dest;
528 s = src;
529 while (count--)
530 *tmp++ = *s++;
531 } else {
532 tmp = dest;
533 tmp += count;
534 s = src;
535 s += count;
536 while (count--)
537 *--tmp = *--s;
538 }
539 return dest;
540 }
541 EXPORT_SYMBOL(memmove);
542 #endif
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 */
551 #undef memcmp
552 int memcmp(const void *cs, const void *ct, size_t count)
553 {
554 const unsigned char *su1, *su2;
555 int res = 0;
557 for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
558 if ((res = *su1 - *su2) != 0)
559 break;
560 return res;
561 }
562 EXPORT_SYMBOL(memcmp);
563 #endif
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 */
575 void *memscan(void *addr, int c, size_t size)
576 {
577 unsigned char *p = addr;
579 while (size) {
580 if (*p == c)
581 return (void *)p;
582 p++;
583 size--;
584 }
585 return (void *)p;
586 }
587 EXPORT_SYMBOL(memscan);
588 #endif
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 */
596 char *strstr(const char *s1, const char *s2)
597 {
598 int l1, l2;
600 l2 = strlen(s2);
601 if (!l2)
602 return (char *)s1;
603 l1 = strlen(s1);
604 while (l1 >= l2) {
605 l1--;
606 if (!memcmp(s1, s2, l2))
607 return (char *)s1;
608 s1++;
609 }
610 return NULL;
611 }
612 EXPORT_SYMBOL(strstr);
613 #endif
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 */
625 void *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++) {
630 return (void *)(p - 1);
631 }
632 }
633 return NULL;
634 }
635 EXPORT_SYMBOL(memchr);
636 #endif