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Commit | Line | Data |
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1da177e4 LT |
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 | ||
850b9247 | 39 | c1 = c2 = 0; |
1da177e4 LT |
40 | if (len) { |
41 | do { | |
51a0f0f6 JJ |
42 | c1 = *s1; |
43 | c2 = *s2; | |
44 | s1++; | |
45 | s2++; | |
1da177e4 LT |
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 | } | |
1da177e4 LT |
60 | EXPORT_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 | */ | |
0c28130b | 69 | #undef strcpy |
51a0f0f6 | 70 | char *strcpy(char *dest, const char *src) |
1da177e4 LT |
71 | { |
72 | char *tmp = dest; | |
73 | ||
74 | while ((*dest++ = *src++) != '\0') | |
75 | /* nothing */; | |
76 | return tmp; | |
77 | } | |
78 | EXPORT_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. | |
25279526 | 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 | * | |
1da177e4 | 94 | */ |
51a0f0f6 | 95 | char *strncpy(char *dest, const char *src, size_t count) |
1da177e4 LT |
96 | { |
97 | char *tmp = dest; | |
98 | ||
99 | while (count) { | |
51a0f0f6 JJ |
100 | if ((*tmp = *src) != 0) |
101 | src++; | |
1da177e4 LT |
102 | tmp++; |
103 | count--; | |
104 | } | |
105 | return dest; | |
106 | } | |
107 | EXPORT_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 | */ | |
122 | size_t strlcpy(char *dest, const char *src, size_t size) | |
123 | { | |
124 | size_t ret = strlen(src); | |
125 | ||
126 | if (size) { | |
51a0f0f6 | 127 | size_t len = (ret >= size) ? size - 1 : ret; |
1da177e4 LT |
128 | memcpy(dest, src, len); |
129 | dest[len] = '\0'; | |
130 | } | |
131 | return ret; | |
132 | } | |
133 | EXPORT_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 | */ | |
0c28130b | 142 | #undef strcat |
51a0f0f6 | 143 | char *strcat(char *dest, const char *src) |
1da177e4 LT |
144 | { |
145 | char *tmp = dest; | |
146 | ||
147 | while (*dest) | |
148 | dest++; | |
149 | while ((*dest++ = *src++) != '\0') | |
150 | ; | |
1da177e4 LT |
151 | return tmp; |
152 | } | |
153 | EXPORT_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 | */ | |
51a0f0f6 | 166 | char *strncat(char *dest, const char *src, size_t count) |
1da177e4 LT |
167 | { |
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 | } | |
1da177e4 LT |
180 | return tmp; |
181 | } | |
182 | EXPORT_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 | */ | |
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; | |
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 | } | |
209 | EXPORT_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 | */ | |
0c28130b | 218 | #undef strcmp |
51a0f0f6 | 219 | int strcmp(const char *cs, const char *ct) |
1da177e4 | 220 | { |
cc75fb71 | 221 | signed char __res; |
1da177e4 LT |
222 | |
223 | while (1) { | |
224 | if ((__res = *cs - *ct++) != 0 || !*cs++) | |
225 | break; | |
226 | } | |
1da177e4 LT |
227 | return __res; |
228 | } | |
229 | EXPORT_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 | */ | |
51a0f0f6 | 239 | int strncmp(const char *cs, const char *ct, size_t count) |
1da177e4 | 240 | { |
cc75fb71 | 241 | signed char __res = 0; |
1da177e4 LT |
242 | |
243 | while (count) { | |
244 | if ((__res = *cs - *ct++) != 0 || !*cs++) | |
245 | break; | |
246 | count--; | |
247 | } | |
1da177e4 LT |
248 | return __res; |
249 | } | |
250 | EXPORT_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 | */ | |
51a0f0f6 | 259 | char *strchr(const char *s, int c) |
1da177e4 | 260 | { |
51a0f0f6 | 261 | for (; *s != (char)c; ++s) |
1da177e4 LT |
262 | if (*s == '\0') |
263 | return NULL; | |
51a0f0f6 | 264 | return (char *)s; |
1da177e4 LT |
265 | } |
266 | EXPORT_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 | */ | |
51a0f0f6 | 275 | char *strrchr(const char *s, int c) |
1da177e4 LT |
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 | |
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 | */ | |
294 | char *strnchr(const char *s, size_t count, int c) | |
295 | { | |
296 | for (; count-- && *s != '\0'; ++s) | |
51a0f0f6 JJ |
297 | if (*s == (char)c) |
298 | return (char *)s; | |
1da177e4 LT |
299 | return NULL; |
300 | } | |
301 | EXPORT_SYMBOL(strnchr); | |
302 | #endif | |
303 | ||
304 | #ifndef __HAVE_ARCH_STRLEN | |
305 | /** | |
306 | * strlen - Find the length of a string | |
307 | * @s: The string to be sized | |
308 | */ | |
51a0f0f6 | 309 | size_t strlen(const char *s) |
1da177e4 LT |
310 | { |
311 | const char *sc; | |
312 | ||
313 | for (sc = s; *sc != '\0'; ++sc) | |
314 | /* nothing */; | |
315 | return sc - s; | |
316 | } | |
317 | EXPORT_SYMBOL(strlen); | |
318 | #endif | |
319 | ||
320 | #ifndef __HAVE_ARCH_STRNLEN | |
321 | /** | |
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 | |
325 | */ | |
51a0f0f6 | 326 | size_t strnlen(const char *s, size_t count) |
1da177e4 LT |
327 | { |
328 | const char *sc; | |
329 | ||
330 | for (sc = s; count-- && *sc != '\0'; ++sc) | |
331 | /* nothing */; | |
332 | return sc - s; | |
333 | } | |
334 | EXPORT_SYMBOL(strnlen); | |
335 | #endif | |
336 | ||
337 | #ifndef __HAVE_ARCH_STRSPN | |
338 | /** | |
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 | |
343 | */ | |
344 | size_t strspn(const char *s, const char *accept) | |
345 | { | |
346 | const char *p; | |
347 | const char *a; | |
348 | size_t count = 0; | |
349 | ||
350 | for (p = s; *p != '\0'; ++p) { | |
351 | for (a = accept; *a != '\0'; ++a) { | |
352 | if (*p == *a) | |
353 | break; | |
354 | } | |
355 | if (*a == '\0') | |
356 | return count; | |
357 | ++count; | |
358 | } | |
1da177e4 LT |
359 | return count; |
360 | } | |
361 | ||
362 | EXPORT_SYMBOL(strspn); | |
363 | #endif | |
364 | ||
365 | /** | |
366 | * strcspn - Calculate the length of the initial substring of @s which does | |
367 | * not contain letters in @reject | |
368 | * @s: The string to be searched | |
369 | * @reject: The string to avoid | |
370 | */ | |
371 | size_t strcspn(const char *s, const char *reject) | |
372 | { | |
373 | const char *p; | |
374 | const char *r; | |
375 | size_t count = 0; | |
376 | ||
377 | for (p = s; *p != '\0'; ++p) { | |
378 | for (r = reject; *r != '\0'; ++r) { | |
379 | if (*p == *r) | |
380 | return count; | |
381 | } | |
382 | ++count; | |
383 | } | |
1da177e4 | 384 | return count; |
51a0f0f6 | 385 | } |
1da177e4 LT |
386 | EXPORT_SYMBOL(strcspn); |
387 | ||
388 | #ifndef __HAVE_ARCH_STRPBRK | |
389 | /** | |
390 | * strpbrk - Find the first occurrence of a set of characters | |
391 | * @cs: The string to be searched | |
392 | * @ct: The characters to search for | |
393 | */ | |
51a0f0f6 | 394 | char *strpbrk(const char *cs, const char *ct) |
1da177e4 | 395 | { |
51a0f0f6 | 396 | const char *sc1, *sc2; |
1da177e4 | 397 | |
51a0f0f6 JJ |
398 | for (sc1 = cs; *sc1 != '\0'; ++sc1) { |
399 | for (sc2 = ct; *sc2 != '\0'; ++sc2) { | |
1da177e4 | 400 | if (*sc1 == *sc2) |
51a0f0f6 | 401 | return (char *)sc1; |
1da177e4 LT |
402 | } |
403 | } | |
404 | return NULL; | |
405 | } | |
406 | EXPORT_SYMBOL(strpbrk); | |
407 | #endif | |
408 | ||
409 | #ifndef __HAVE_ARCH_STRSEP | |
410 | /** | |
411 | * strsep - Split a string into tokens | |
412 | * @s: The string to be searched | |
413 | * @ct: The characters to search for | |
414 | * | |
415 | * strsep() updates @s to point after the token, ready for the next call. | |
416 | * | |
417 | * It returns empty tokens, too, behaving exactly like the libc function | |
418 | * of that name. In fact, it was stolen from glibc2 and de-fancy-fied. | |
419 | * Same semantics, slimmer shape. ;) | |
420 | */ | |
51a0f0f6 | 421 | char *strsep(char **s, const char *ct) |
1da177e4 | 422 | { |
51a0f0f6 JJ |
423 | char *sbegin = *s; |
424 | char *end; | |
1da177e4 LT |
425 | |
426 | if (sbegin == NULL) | |
427 | return NULL; | |
428 | ||
429 | end = strpbrk(sbegin, ct); | |
430 | if (end) | |
431 | *end++ = '\0'; | |
432 | *s = end; | |
1da177e4 LT |
433 | return sbegin; |
434 | } | |
1da177e4 LT |
435 | EXPORT_SYMBOL(strsep); |
436 | #endif | |
437 | ||
438 | #ifndef __HAVE_ARCH_MEMSET | |
439 | /** | |
440 | * memset - Fill a region of memory with the given value | |
441 | * @s: Pointer to the start of the area. | |
442 | * @c: The byte to fill the area with | |
443 | * @count: The size of the area. | |
444 | * | |
445 | * Do not use memset() to access IO space, use memset_io() instead. | |
446 | */ | |
51a0f0f6 | 447 | void *memset(void *s, int c, size_t count) |
1da177e4 | 448 | { |
850b9247 | 449 | char *xs = s; |
1da177e4 LT |
450 | |
451 | while (count--) | |
452 | *xs++ = c; | |
1da177e4 LT |
453 | return s; |
454 | } | |
455 | EXPORT_SYMBOL(memset); | |
456 | #endif | |
457 | ||
458 | #ifndef __HAVE_ARCH_MEMCPY | |
459 | /** | |
460 | * memcpy - Copy one area of memory to another | |
461 | * @dest: Where to copy to | |
462 | * @src: Where to copy from | |
463 | * @count: The size of the area. | |
464 | * | |
465 | * You should not use this function to access IO space, use memcpy_toio() | |
466 | * or memcpy_fromio() instead. | |
467 | */ | |
51a0f0f6 | 468 | void *memcpy(void *dest, const void *src, size_t count) |
1da177e4 | 469 | { |
850b9247 JJ |
470 | char *tmp = dest; |
471 | char *s = src; | |
1da177e4 LT |
472 | |
473 | while (count--) | |
474 | *tmp++ = *s++; | |
1da177e4 LT |
475 | return dest; |
476 | } | |
477 | EXPORT_SYMBOL(memcpy); | |
478 | #endif | |
479 | ||
480 | #ifndef __HAVE_ARCH_MEMMOVE | |
481 | /** | |
482 | * memmove - Copy one area of memory to another | |
483 | * @dest: Where to copy to | |
484 | * @src: Where to copy from | |
485 | * @count: The size of the area. | |
486 | * | |
487 | * Unlike memcpy(), memmove() copes with overlapping areas. | |
488 | */ | |
51a0f0f6 | 489 | void *memmove(void *dest, const void *src, size_t count) |
1da177e4 | 490 | { |
82da2c37 PJ |
491 | char *tmp; |
492 | const char *s; | |
1da177e4 LT |
493 | |
494 | if (dest <= src) { | |
850b9247 JJ |
495 | tmp = dest; |
496 | s = src; | |
1da177e4 LT |
497 | while (count--) |
498 | *tmp++ = *s++; | |
51a0f0f6 | 499 | } else { |
850b9247 JJ |
500 | tmp = dest; |
501 | tmp += count; | |
502 | s = src; | |
503 | s += count; | |
1da177e4 LT |
504 | while (count--) |
505 | *--tmp = *--s; | |
51a0f0f6 | 506 | } |
1da177e4 LT |
507 | return dest; |
508 | } | |
509 | EXPORT_SYMBOL(memmove); | |
510 | #endif | |
511 | ||
512 | #ifndef __HAVE_ARCH_MEMCMP | |
513 | /** | |
514 | * memcmp - Compare two areas of memory | |
515 | * @cs: One area of memory | |
516 | * @ct: Another area of memory | |
517 | * @count: The size of the area. | |
518 | */ | |
0c28130b | 519 | #undef memcmp |
51a0f0f6 | 520 | int memcmp(const void *cs, const void *ct, size_t count) |
1da177e4 LT |
521 | { |
522 | const unsigned char *su1, *su2; | |
523 | int res = 0; | |
524 | ||
51a0f0f6 | 525 | for (su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--) |
1da177e4 LT |
526 | if ((res = *su1 - *su2) != 0) |
527 | break; | |
528 | return res; | |
529 | } | |
530 | EXPORT_SYMBOL(memcmp); | |
531 | #endif | |
532 | ||
533 | #ifndef __HAVE_ARCH_MEMSCAN | |
534 | /** | |
535 | * memscan - Find a character in an area of memory. | |
536 | * @addr: The memory area | |
537 | * @c: The byte to search for | |
538 | * @size: The size of the area. | |
539 | * | |
540 | * returns the address of the first occurrence of @c, or 1 byte past | |
541 | * the area if @c is not found | |
542 | */ | |
51a0f0f6 | 543 | void *memscan(void *addr, int c, size_t size) |
1da177e4 | 544 | { |
850b9247 | 545 | unsigned char *p = addr; |
1da177e4 LT |
546 | |
547 | while (size) { | |
548 | if (*p == c) | |
51a0f0f6 | 549 | return (void *)p; |
1da177e4 LT |
550 | p++; |
551 | size--; | |
552 | } | |
51a0f0f6 | 553 | return (void *)p; |
1da177e4 LT |
554 | } |
555 | EXPORT_SYMBOL(memscan); | |
556 | #endif | |
557 | ||
558 | #ifndef __HAVE_ARCH_STRSTR | |
559 | /** | |
560 | * strstr - Find the first substring in a %NUL terminated string | |
561 | * @s1: The string to be searched | |
562 | * @s2: The string to search for | |
563 | */ | |
51a0f0f6 | 564 | char *strstr(const char *s1, const char *s2) |
1da177e4 LT |
565 | { |
566 | int l1, l2; | |
567 | ||
568 | l2 = strlen(s2); | |
569 | if (!l2) | |
51a0f0f6 | 570 | return (char *)s1; |
1da177e4 LT |
571 | l1 = strlen(s1); |
572 | while (l1 >= l2) { | |
573 | l1--; | |
51a0f0f6 JJ |
574 | if (!memcmp(s1, s2, l2)) |
575 | return (char *)s1; | |
1da177e4 LT |
576 | s1++; |
577 | } | |
578 | return NULL; | |
579 | } | |
580 | EXPORT_SYMBOL(strstr); | |
581 | #endif | |
582 | ||
583 | #ifndef __HAVE_ARCH_MEMCHR | |
584 | /** | |
585 | * memchr - Find a character in an area of memory. | |
586 | * @s: The memory area | |
587 | * @c: The byte to search for | |
588 | * @n: The size of the area. | |
589 | * | |
590 | * returns the address of the first occurrence of @c, or %NULL | |
591 | * if @c is not found | |
592 | */ | |
593 | void *memchr(const void *s, int c, size_t n) | |
594 | { | |
595 | const unsigned char *p = s; | |
596 | while (n-- != 0) { | |
597 | if ((unsigned char)c == *p++) { | |
51a0f0f6 | 598 | return (void *)(p - 1); |
1da177e4 LT |
599 | } |
600 | } | |
601 | return NULL; | |
602 | } | |
603 | EXPORT_SYMBOL(memchr); | |
604 | #endif |