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1 | /* |
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 | */ | |
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; | |
38 | ||
39 | c1 = 0; c2 = 0; | |
40 | if (len) { | |
41 | do { | |
42 | c1 = *s1; c2 = *s2; | |
43 | s1++; s2++; | |
44 | if (!c1) | |
45 | break; | |
46 | if (!c2) | |
47 | break; | |
48 | if (c1 == c2) | |
49 | continue; | |
50 | c1 = tolower(c1); | |
51 | c2 = tolower(c2); | |
52 | if (c1 != c2) | |
53 | break; | |
54 | } while (--len); | |
55 | } | |
56 | return (int)c1 - (int)c2; | |
57 | } | |
58 | ||
59 | EXPORT_SYMBOL(strnicmp); | |
60 | #endif | |
61 | ||
62 | #ifndef __HAVE_ARCH_STRCPY | |
63 | /** | |
64 | * strcpy - Copy a %NUL terminated string | |
65 | * @dest: Where to copy the string to | |
66 | * @src: Where to copy the string from | |
67 | */ | |
68 | char * strcpy(char * dest,const char *src) | |
69 | { | |
70 | char *tmp = dest; | |
71 | ||
72 | while ((*dest++ = *src++) != '\0') | |
73 | /* nothing */; | |
74 | return tmp; | |
75 | } | |
76 | EXPORT_SYMBOL(strcpy); | |
77 | #endif | |
78 | ||
79 | #ifndef __HAVE_ARCH_STRNCPY | |
80 | /** | |
81 | * strncpy - Copy a length-limited, %NUL-terminated string | |
82 | * @dest: Where to copy the string to | |
83 | * @src: Where to copy the string from | |
84 | * @count: The maximum number of bytes to copy | |
85 | * | |
86 | * The result is not %NUL-terminated if the source exceeds | |
87 | * @count bytes. | |
88 | */ | |
89 | char * strncpy(char * dest,const char *src,size_t count) | |
90 | { | |
91 | char *tmp = dest; | |
92 | ||
93 | while (count) { | |
94 | if ((*tmp = *src) != 0) src++; | |
95 | tmp++; | |
96 | count--; | |
97 | } | |
98 | return dest; | |
99 | } | |
100 | EXPORT_SYMBOL(strncpy); | |
101 | #endif | |
102 | ||
103 | #ifndef __HAVE_ARCH_STRLCPY | |
104 | /** | |
105 | * strlcpy - Copy a %NUL terminated string into a sized buffer | |
106 | * @dest: Where to copy the string to | |
107 | * @src: Where to copy the string from | |
108 | * @size: size of destination buffer | |
109 | * | |
110 | * Compatible with *BSD: the result is always a valid | |
111 | * NUL-terminated string that fits in the buffer (unless, | |
112 | * of course, the buffer size is zero). It does not pad | |
113 | * out the result like strncpy() does. | |
114 | */ | |
115 | size_t strlcpy(char *dest, const char *src, size_t size) | |
116 | { | |
117 | size_t ret = strlen(src); | |
118 | ||
119 | if (size) { | |
120 | size_t len = (ret >= size) ? size-1 : ret; | |
121 | memcpy(dest, src, len); | |
122 | dest[len] = '\0'; | |
123 | } | |
124 | return ret; | |
125 | } | |
126 | EXPORT_SYMBOL(strlcpy); | |
127 | #endif | |
128 | ||
129 | #ifndef __HAVE_ARCH_STRCAT | |
130 | /** | |
131 | * strcat - Append one %NUL-terminated string to another | |
132 | * @dest: The string to be appended to | |
133 | * @src: The string to append to it | |
134 | */ | |
135 | char * strcat(char * dest, const char * src) | |
136 | { | |
137 | char *tmp = dest; | |
138 | ||
139 | while (*dest) | |
140 | dest++; | |
141 | while ((*dest++ = *src++) != '\0') | |
142 | ; | |
143 | ||
144 | return tmp; | |
145 | } | |
146 | EXPORT_SYMBOL(strcat); | |
147 | #endif | |
148 | ||
149 | #ifndef __HAVE_ARCH_STRNCAT | |
150 | /** | |
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 | |
155 | * | |
156 | * Note that in contrast to strncpy, strncat ensures the result is | |
157 | * terminated. | |
158 | */ | |
159 | char * strncat(char *dest, const char *src, size_t count) | |
160 | { | |
161 | char *tmp = dest; | |
162 | ||
163 | if (count) { | |
164 | while (*dest) | |
165 | dest++; | |
166 | while ((*dest++ = *src++) != 0) { | |
167 | if (--count == 0) { | |
168 | *dest = '\0'; | |
169 | break; | |
170 | } | |
171 | } | |
172 | } | |
173 | ||
174 | return tmp; | |
175 | } | |
176 | EXPORT_SYMBOL(strncat); | |
177 | #endif | |
178 | ||
179 | #ifndef __HAVE_ARCH_STRLCAT | |
180 | /** | |
181 | * strlcat - Append a length-limited, %NUL-terminated string to another | |
182 | * @dest: The string to be appended to | |
183 | * @src: The string to append to it | |
184 | * @count: The size of the destination buffer. | |
185 | */ | |
186 | size_t strlcat(char *dest, const char *src, size_t count) | |
187 | { | |
188 | size_t dsize = strlen(dest); | |
189 | size_t len = strlen(src); | |
190 | size_t res = dsize + len; | |
191 | ||
192 | /* This would be a bug */ | |
193 | BUG_ON(dsize >= count); | |
194 | ||
195 | dest += dsize; | |
196 | count -= dsize; | |
197 | if (len >= count) | |
198 | len = count-1; | |
199 | memcpy(dest, src, len); | |
200 | dest[len] = 0; | |
201 | return res; | |
202 | } | |
203 | EXPORT_SYMBOL(strlcat); | |
204 | #endif | |
205 | ||
206 | #ifndef __HAVE_ARCH_STRCMP | |
207 | /** | |
208 | * strcmp - Compare two strings | |
209 | * @cs: One string | |
210 | * @ct: Another string | |
211 | */ | |
212 | int strcmp(const char * cs,const char * ct) | |
213 | { | |
214 | register signed char __res; | |
215 | ||
216 | while (1) { | |
217 | if ((__res = *cs - *ct++) != 0 || !*cs++) | |
218 | break; | |
219 | } | |
220 | ||
221 | return __res; | |
222 | } | |
223 | EXPORT_SYMBOL(strcmp); | |
224 | #endif | |
225 | ||
226 | #ifndef __HAVE_ARCH_STRNCMP | |
227 | /** | |
228 | * strncmp - Compare two length-limited strings | |
229 | * @cs: One string | |
230 | * @ct: Another string | |
231 | * @count: The maximum number of bytes to compare | |
232 | */ | |
233 | int strncmp(const char * cs,const char * ct,size_t count) | |
234 | { | |
235 | register signed char __res = 0; | |
236 | ||
237 | while (count) { | |
238 | if ((__res = *cs - *ct++) != 0 || !*cs++) | |
239 | break; | |
240 | count--; | |
241 | } | |
242 | ||
243 | return __res; | |
244 | } | |
245 | EXPORT_SYMBOL(strncmp); | |
246 | #endif | |
247 | ||
248 | #ifndef __HAVE_ARCH_STRCHR | |
249 | /** | |
250 | * strchr - Find the first occurrence of a character in a string | |
251 | * @s: The string to be searched | |
252 | * @c: The character to search for | |
253 | */ | |
254 | char * strchr(const char * s, int c) | |
255 | { | |
256 | for(; *s != (char) c; ++s) | |
257 | if (*s == '\0') | |
258 | return NULL; | |
259 | return (char *) s; | |
260 | } | |
261 | EXPORT_SYMBOL(strchr); | |
262 | #endif | |
263 | ||
264 | #ifndef __HAVE_ARCH_STRRCHR | |
265 | /** | |
266 | * strrchr - Find the last occurrence of a character in a string | |
267 | * @s: The string to be searched | |
268 | * @c: The character to search for | |
269 | */ | |
270 | char * strrchr(const char * s, int c) | |
271 | { | |
272 | const char *p = s + strlen(s); | |
273 | do { | |
274 | if (*p == (char)c) | |
275 | return (char *)p; | |
276 | } while (--p >= s); | |
277 | return NULL; | |
278 | } | |
279 | EXPORT_SYMBOL(strrchr); | |
280 | #endif | |
281 | ||
282 | #ifndef __HAVE_ARCH_STRNCHR | |
283 | /** | |
284 | * strnchr - Find a character in a length limited string | |
285 | * @s: The string to be searched | |
286 | * @count: The number of characters to be searched | |
287 | * @c: The character to search for | |
288 | */ | |
289 | char *strnchr(const char *s, size_t count, int c) | |
290 | { | |
291 | for (; count-- && *s != '\0'; ++s) | |
292 | if (*s == (char) c) | |
293 | return (char *) s; | |
294 | return NULL; | |
295 | } | |
296 | EXPORT_SYMBOL(strnchr); | |
297 | #endif | |
298 | ||
299 | #ifndef __HAVE_ARCH_STRLEN | |
300 | /** | |
301 | * strlen - Find the length of a string | |
302 | * @s: The string to be sized | |
303 | */ | |
304 | size_t strlen(const char * s) | |
305 | { | |
306 | const char *sc; | |
307 | ||
308 | for (sc = s; *sc != '\0'; ++sc) | |
309 | /* nothing */; | |
310 | return sc - s; | |
311 | } | |
312 | EXPORT_SYMBOL(strlen); | |
313 | #endif | |
314 | ||
315 | #ifndef __HAVE_ARCH_STRNLEN | |
316 | /** | |
317 | * strnlen - Find the length of a length-limited string | |
318 | * @s: The string to be sized | |
319 | * @count: The maximum number of bytes to search | |
320 | */ | |
321 | size_t strnlen(const char * s, size_t count) | |
322 | { | |
323 | const char *sc; | |
324 | ||
325 | for (sc = s; count-- && *sc != '\0'; ++sc) | |
326 | /* nothing */; | |
327 | return sc - s; | |
328 | } | |
329 | EXPORT_SYMBOL(strnlen); | |
330 | #endif | |
331 | ||
332 | #ifndef __HAVE_ARCH_STRSPN | |
333 | /** | |
334 | * strspn - Calculate the length of the initial substring of @s which only | |
335 | * contain letters in @accept | |
336 | * @s: The string to be searched | |
337 | * @accept: The string to search for | |
338 | */ | |
339 | size_t strspn(const char *s, const char *accept) | |
340 | { | |
341 | const char *p; | |
342 | const char *a; | |
343 | size_t count = 0; | |
344 | ||
345 | for (p = s; *p != '\0'; ++p) { | |
346 | for (a = accept; *a != '\0'; ++a) { | |
347 | if (*p == *a) | |
348 | break; | |
349 | } | |
350 | if (*a == '\0') | |
351 | return count; | |
352 | ++count; | |
353 | } | |
354 | ||
355 | return count; | |
356 | } | |
357 | ||
358 | EXPORT_SYMBOL(strspn); | |
359 | #endif | |
360 | ||
361 | /** | |
362 | * strcspn - Calculate the length of the initial substring of @s which does | |
363 | * not contain letters in @reject | |
364 | * @s: The string to be searched | |
365 | * @reject: The string to avoid | |
366 | */ | |
367 | size_t strcspn(const char *s, const char *reject) | |
368 | { | |
369 | const char *p; | |
370 | const char *r; | |
371 | size_t count = 0; | |
372 | ||
373 | for (p = s; *p != '\0'; ++p) { | |
374 | for (r = reject; *r != '\0'; ++r) { | |
375 | if (*p == *r) | |
376 | return count; | |
377 | } | |
378 | ++count; | |
379 | } | |
380 | ||
381 | return count; | |
382 | } | |
383 | EXPORT_SYMBOL(strcspn); | |
384 | ||
385 | #ifndef __HAVE_ARCH_STRPBRK | |
386 | /** | |
387 | * strpbrk - Find the first occurrence of a set of characters | |
388 | * @cs: The string to be searched | |
389 | * @ct: The characters to search for | |
390 | */ | |
391 | char * strpbrk(const char * cs,const char * ct) | |
392 | { | |
393 | const char *sc1,*sc2; | |
394 | ||
395 | for( sc1 = cs; *sc1 != '\0'; ++sc1) { | |
396 | for( sc2 = ct; *sc2 != '\0'; ++sc2) { | |
397 | if (*sc1 == *sc2) | |
398 | return (char *) sc1; | |
399 | } | |
400 | } | |
401 | return NULL; | |
402 | } | |
403 | EXPORT_SYMBOL(strpbrk); | |
404 | #endif | |
405 | ||
406 | #ifndef __HAVE_ARCH_STRSEP | |
407 | /** | |
408 | * strsep - Split a string into tokens | |
409 | * @s: The string to be searched | |
410 | * @ct: The characters to search for | |
411 | * | |
412 | * strsep() updates @s to point after the token, ready for the next call. | |
413 | * | |
414 | * It returns empty tokens, too, behaving exactly like the libc function | |
415 | * of that name. In fact, it was stolen from glibc2 and de-fancy-fied. | |
416 | * Same semantics, slimmer shape. ;) | |
417 | */ | |
418 | char * strsep(char **s, const char *ct) | |
419 | { | |
420 | char *sbegin = *s, *end; | |
421 | ||
422 | if (sbegin == NULL) | |
423 | return NULL; | |
424 | ||
425 | end = strpbrk(sbegin, ct); | |
426 | if (end) | |
427 | *end++ = '\0'; | |
428 | *s = end; | |
429 | ||
430 | return sbegin; | |
431 | } | |
432 | ||
433 | EXPORT_SYMBOL(strsep); | |
434 | #endif | |
435 | ||
436 | #ifndef __HAVE_ARCH_MEMSET | |
437 | /** | |
438 | * memset - Fill a region of memory with the given value | |
439 | * @s: Pointer to the start of the area. | |
440 | * @c: The byte to fill the area with | |
441 | * @count: The size of the area. | |
442 | * | |
443 | * Do not use memset() to access IO space, use memset_io() instead. | |
444 | */ | |
445 | void * memset(void * s,int c,size_t count) | |
446 | { | |
447 | char *xs = (char *) s; | |
448 | ||
449 | while (count--) | |
450 | *xs++ = c; | |
451 | ||
452 | return s; | |
453 | } | |
454 | EXPORT_SYMBOL(memset); | |
455 | #endif | |
456 | ||
457 | #ifndef __HAVE_ARCH_MEMCPY | |
458 | /** | |
459 | * memcpy - Copy one area of memory to another | |
460 | * @dest: Where to copy to | |
461 | * @src: Where to copy from | |
462 | * @count: The size of the area. | |
463 | * | |
464 | * You should not use this function to access IO space, use memcpy_toio() | |
465 | * or memcpy_fromio() instead. | |
466 | */ | |
467 | void * memcpy(void * dest,const void *src,size_t count) | |
468 | { | |
469 | char *tmp = (char *) dest, *s = (char *) src; | |
470 | ||
471 | while (count--) | |
472 | *tmp++ = *s++; | |
473 | ||
474 | return dest; | |
475 | } | |
476 | EXPORT_SYMBOL(memcpy); | |
477 | #endif | |
478 | ||
479 | #ifndef __HAVE_ARCH_MEMMOVE | |
480 | /** | |
481 | * memmove - Copy one area of memory to another | |
482 | * @dest: Where to copy to | |
483 | * @src: Where to copy from | |
484 | * @count: The size of the area. | |
485 | * | |
486 | * Unlike memcpy(), memmove() copes with overlapping areas. | |
487 | */ | |
488 | void * memmove(void * dest,const void *src,size_t count) | |
489 | { | |
490 | char *tmp, *s; | |
491 | ||
492 | if (dest <= src) { | |
493 | tmp = (char *) dest; | |
494 | s = (char *) src; | |
495 | while (count--) | |
496 | *tmp++ = *s++; | |
497 | } | |
498 | else { | |
499 | tmp = (char *) dest + count; | |
500 | s = (char *) src + count; | |
501 | while (count--) | |
502 | *--tmp = *--s; | |
503 | } | |
504 | ||
505 | return dest; | |
506 | } | |
507 | EXPORT_SYMBOL(memmove); | |
508 | #endif | |
509 | ||
510 | #ifndef __HAVE_ARCH_MEMCMP | |
511 | /** | |
512 | * memcmp - Compare two areas of memory | |
513 | * @cs: One area of memory | |
514 | * @ct: Another area of memory | |
515 | * @count: The size of the area. | |
516 | */ | |
517 | int memcmp(const void * cs,const void * ct,size_t count) | |
518 | { | |
519 | const unsigned char *su1, *su2; | |
520 | int res = 0; | |
521 | ||
522 | for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) | |
523 | if ((res = *su1 - *su2) != 0) | |
524 | break; | |
525 | return res; | |
526 | } | |
527 | EXPORT_SYMBOL(memcmp); | |
528 | #endif | |
529 | ||
530 | #ifndef __HAVE_ARCH_MEMSCAN | |
531 | /** | |
532 | * memscan - Find a character in an area of memory. | |
533 | * @addr: The memory area | |
534 | * @c: The byte to search for | |
535 | * @size: The size of the area. | |
536 | * | |
537 | * returns the address of the first occurrence of @c, or 1 byte past | |
538 | * the area if @c is not found | |
539 | */ | |
540 | void * memscan(void * addr, int c, size_t size) | |
541 | { | |
542 | unsigned char * p = (unsigned char *) addr; | |
543 | ||
544 | while (size) { | |
545 | if (*p == c) | |
546 | return (void *) p; | |
547 | p++; | |
548 | size--; | |
549 | } | |
550 | return (void *) p; | |
551 | } | |
552 | EXPORT_SYMBOL(memscan); | |
553 | #endif | |
554 | ||
555 | #ifndef __HAVE_ARCH_STRSTR | |
556 | /** | |
557 | * strstr - Find the first substring in a %NUL terminated string | |
558 | * @s1: The string to be searched | |
559 | * @s2: The string to search for | |
560 | */ | |
561 | char * strstr(const char * s1,const char * s2) | |
562 | { | |
563 | int l1, l2; | |
564 | ||
565 | l2 = strlen(s2); | |
566 | if (!l2) | |
567 | return (char *) s1; | |
568 | l1 = strlen(s1); | |
569 | while (l1 >= l2) { | |
570 | l1--; | |
571 | if (!memcmp(s1,s2,l2)) | |
572 | return (char *) s1; | |
573 | s1++; | |
574 | } | |
575 | return NULL; | |
576 | } | |
577 | EXPORT_SYMBOL(strstr); | |
578 | #endif | |
579 | ||
580 | #ifndef __HAVE_ARCH_MEMCHR | |
581 | /** | |
582 | * memchr - Find a character in an area of memory. | |
583 | * @s: The memory area | |
584 | * @c: The byte to search for | |
585 | * @n: The size of the area. | |
586 | * | |
587 | * returns the address of the first occurrence of @c, or %NULL | |
588 | * if @c is not found | |
589 | */ | |
590 | void *memchr(const void *s, int c, size_t n) | |
591 | { | |
592 | const unsigned char *p = s; | |
593 | while (n-- != 0) { | |
594 | if ((unsigned char)c == *p++) { | |
595 | return (void *)(p-1); | |
596 | } | |
597 | } | |
598 | return NULL; | |
599 | } | |
600 | EXPORT_SYMBOL(memchr); | |
601 | #endif |