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wdenkc6097192002-11-03 00:24:07 +00001/*
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
18#include <linux/types.h>
19#include <linux/string.h>
20#include <linux/ctype.h>
21#include <malloc.h>
22
wdenkc6097192002-11-03 00:24:07 +000023
Wolfgang Denk983bebb2006-05-03 01:00:39 +020024#if 0 /* not used - was: #ifndef __HAVE_ARCH_STRNICMP */
wdenkc6097192002-11-03 00:24:07 +000025/**
26 * strnicmp - Case insensitive, length-limited string comparison
27 * @s1: One string
28 * @s2: The other string
29 * @len: the maximum number of characters to compare
30 */
31int strnicmp(const char *s1, const char *s2, size_t len)
32{
33 /* Yes, Virginia, it had better be unsigned */
34 unsigned char c1, c2;
35
36 c1 = 0; c2 = 0;
37 if (len) {
38 do {
39 c1 = *s1; c2 = *s2;
40 s1++; s2++;
41 if (!c1)
42 break;
43 if (!c2)
44 break;
45 if (c1 == c2)
46 continue;
47 c1 = tolower(c1);
48 c2 = tolower(c2);
49 if (c1 != c2)
50 break;
51 } while (--len);
52 }
53 return (int)c1 - (int)c2;
54}
55#endif
56
57char * ___strtok;
58
59#ifndef __HAVE_ARCH_STRCPY
60/**
61 * strcpy - Copy a %NUL terminated string
62 * @dest: Where to copy the string to
63 * @src: Where to copy the string from
64 */
65char * strcpy(char * dest,const char *src)
66{
67 char *tmp = dest;
68
69 while ((*dest++ = *src++) != '\0')
70 /* nothing */;
71 return tmp;
72}
73#endif
74
75#ifndef __HAVE_ARCH_STRNCPY
76/**
77 * strncpy - Copy a length-limited, %NUL-terminated string
78 * @dest: Where to copy the string to
79 * @src: Where to copy the string from
80 * @count: The maximum number of bytes to copy
81 *
82 * Note that unlike userspace strncpy, this does not %NUL-pad the buffer.
83 * However, the result is not %NUL-terminated if the source exceeds
84 * @count bytes.
85 */
86char * strncpy(char * dest,const char *src,size_t count)
87{
88 char *tmp = dest;
89
90 while (count-- && (*dest++ = *src++) != '\0')
91 /* nothing */;
92
93 return tmp;
94}
95#endif
96
97#ifndef __HAVE_ARCH_STRCAT
98/**
99 * strcat - Append one %NUL-terminated string to another
100 * @dest: The string to be appended to
101 * @src: The string to append to it
102 */
103char * strcat(char * dest, const char * src)
104{
105 char *tmp = dest;
106
107 while (*dest)
108 dest++;
109 while ((*dest++ = *src++) != '\0')
110 ;
111
112 return tmp;
113}
114#endif
115
116#ifndef __HAVE_ARCH_STRNCAT
117/**
118 * strncat - Append a length-limited, %NUL-terminated string to another
119 * @dest: The string to be appended to
120 * @src: The string to append to it
121 * @count: The maximum numbers of bytes to copy
122 *
123 * Note that in contrast to strncpy, strncat ensures the result is
124 * terminated.
125 */
126char * strncat(char *dest, const char *src, size_t count)
127{
128 char *tmp = dest;
129
130 if (count) {
131 while (*dest)
132 dest++;
133 while ((*dest++ = *src++)) {
134 if (--count == 0) {
135 *dest = '\0';
136 break;
137 }
138 }
139 }
140
141 return tmp;
142}
143#endif
144
145#ifndef __HAVE_ARCH_STRCMP
146/**
147 * strcmp - Compare two strings
148 * @cs: One string
149 * @ct: Another string
150 */
151int strcmp(const char * cs,const char * ct)
152{
153 register signed char __res;
154
155 while (1) {
156 if ((__res = *cs - *ct++) != 0 || !*cs++)
157 break;
158 }
159
160 return __res;
161}
162#endif
163
164#ifndef __HAVE_ARCH_STRNCMP
165/**
166 * strncmp - Compare two length-limited strings
167 * @cs: One string
168 * @ct: Another string
169 * @count: The maximum number of bytes to compare
170 */
171int strncmp(const char * cs,const char * ct,size_t count)
172{
173 register signed char __res = 0;
174
175 while (count) {
176 if ((__res = *cs - *ct++) != 0 || !*cs++)
177 break;
178 count--;
179 }
180
181 return __res;
182}
183#endif
184
185#ifndef __HAVE_ARCH_STRCHR
186/**
187 * strchr - Find the first occurrence of a character in a string
188 * @s: The string to be searched
189 * @c: The character to search for
190 */
191char * strchr(const char * s, int c)
192{
193 for(; *s != (char) c; ++s)
194 if (*s == '\0')
195 return NULL;
196 return (char *) s;
197}
198#endif
199
200#ifndef __HAVE_ARCH_STRRCHR
201/**
202 * strrchr - Find the last occurrence of a character in a string
203 * @s: The string to be searched
204 * @c: The character to search for
205 */
206char * strrchr(const char * s, int c)
207{
208 const char *p = s + strlen(s);
209 do {
wdenk8bde7f72003-06-27 21:31:46 +0000210 if (*p == (char)c)
211 return (char *)p;
wdenkc6097192002-11-03 00:24:07 +0000212 } while (--p >= s);
213 return NULL;
214}
215#endif
216
Christian Hitz5454ddb2011-10-12 09:32:05 +0200217
218/**
219 * skip_spaces - Removes leading whitespace from @str.
220 * @str: The string to be stripped.
221 *
222 * Returns a pointer to the first non-whitespace character in @str.
223 */
224char *skip_spaces(const char *str)
225{
226 while (isspace(*str))
227 ++str;
228 return (char *)str;
229}
230
231/**
232 * strim - Removes leading and trailing whitespace from @s.
233 * @s: The string to be stripped.
234 *
235 * Note that the first trailing whitespace is replaced with a %NUL-terminator
236 * in the given string @s. Returns a pointer to the first non-whitespace
237 * character in @s.
238 */
239char *strim(char *s)
240{
241 size_t size;
242 char *end;
243
244 s = skip_spaces(s);
245 size = strlen(s);
246 if (!size)
247 return s;
248
249 end = s + size - 1;
250 while (end >= s && isspace(*end))
251 end--;
252 *(end + 1) = '\0';
253
254 return s;
255}
wdenkc6097192002-11-03 00:24:07 +0000256#ifndef __HAVE_ARCH_STRLEN
257/**
258 * strlen - Find the length of a string
259 * @s: The string to be sized
260 */
261size_t strlen(const char * s)
262{
263 const char *sc;
264
265 for (sc = s; *sc != '\0'; ++sc)
266 /* nothing */;
267 return sc - s;
268}
269#endif
270
271#ifndef __HAVE_ARCH_STRNLEN
272/**
273 * strnlen - Find the length of a length-limited string
274 * @s: The string to be sized
275 * @count: The maximum number of bytes to search
276 */
277size_t strnlen(const char * s, size_t count)
278{
279 const char *sc;
280
281 for (sc = s; count-- && *sc != '\0'; ++sc)
282 /* nothing */;
283 return sc - s;
284}
285#endif
286
287#ifndef __HAVE_ARCH_STRDUP
288char * strdup(const char *s)
289{
290 char *new;
291
292 if ((s == NULL) ||
293 ((new = malloc (strlen(s) + 1)) == NULL) ) {
294 return NULL;
295 }
296
297 strcpy (new, s);
298 return new;
299}
300#endif
301
302#ifndef __HAVE_ARCH_STRSPN
303/**
304 * strspn - Calculate the length of the initial substring of @s which only
Wolfgang Denk53677ef2008-05-20 16:00:29 +0200305 * contain letters in @accept
wdenkc6097192002-11-03 00:24:07 +0000306 * @s: The string to be searched
307 * @accept: The string to search for
308 */
309size_t strspn(const char *s, const char *accept)
310{
311 const char *p;
312 const char *a;
313 size_t count = 0;
314
315 for (p = s; *p != '\0'; ++p) {
316 for (a = accept; *a != '\0'; ++a) {
317 if (*p == *a)
318 break;
319 }
320 if (*a == '\0')
321 return count;
322 ++count;
323 }
324
325 return count;
326}
327#endif
328
329#ifndef __HAVE_ARCH_STRPBRK
330/**
331 * strpbrk - Find the first occurrence of a set of characters
332 * @cs: The string to be searched
333 * @ct: The characters to search for
334 */
335char * strpbrk(const char * cs,const char * ct)
336{
337 const char *sc1,*sc2;
338
339 for( sc1 = cs; *sc1 != '\0'; ++sc1) {
340 for( sc2 = ct; *sc2 != '\0'; ++sc2) {
341 if (*sc1 == *sc2)
342 return (char *) sc1;
343 }
344 }
345 return NULL;
346}
347#endif
348
349#ifndef __HAVE_ARCH_STRTOK
350/**
351 * strtok - Split a string into tokens
352 * @s: The string to be searched
353 * @ct: The characters to search for
354 *
355 * WARNING: strtok is deprecated, use strsep instead.
356 */
357char * strtok(char * s,const char * ct)
358{
359 char *sbegin, *send;
360
361 sbegin = s ? s : ___strtok;
362 if (!sbegin) {
363 return NULL;
364 }
365 sbegin += strspn(sbegin,ct);
366 if (*sbegin == '\0') {
367 ___strtok = NULL;
368 return( NULL );
369 }
370 send = strpbrk( sbegin, ct);
371 if (send && *send != '\0')
372 *send++ = '\0';
373 ___strtok = send;
374 return (sbegin);
375}
376#endif
377
378#ifndef __HAVE_ARCH_STRSEP
379/**
380 * strsep - Split a string into tokens
381 * @s: The string to be searched
382 * @ct: The characters to search for
383 *
384 * strsep() updates @s to point after the token, ready for the next call.
385 *
386 * It returns empty tokens, too, behaving exactly like the libc function
387 * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
388 * Same semantics, slimmer shape. ;)
389 */
390char * strsep(char **s, const char *ct)
391{
392 char *sbegin = *s, *end;
393
394 if (sbegin == NULL)
395 return NULL;
396
397 end = strpbrk(sbegin, ct);
398 if (end)
399 *end++ = '\0';
400 *s = end;
401
402 return sbegin;
403}
404#endif
405
wdenkc3f9d492004-03-14 00:59:59 +0000406#ifndef __HAVE_ARCH_STRSWAB
407/**
408 * strswab - swap adjacent even and odd bytes in %NUL-terminated string
409 * s: address of the string
410 *
411 * returns the address of the swapped string or NULL on error. If
412 * string length is odd, last byte is untouched.
413 */
414char *strswab(const char *s)
415{
Wolfgang Denk389db1f2005-09-25 16:15:17 +0200416 char *p, *q;
wdenkc3f9d492004-03-14 00:59:59 +0000417
418 if ((NULL == s) || ('\0' == *s)) {
419 return (NULL);
420 }
421
Wolfgang Denke5e98ed2005-10-04 23:38:07 +0200422 for (p=(char *)s, q=p+1; (*p != '\0') && (*q != '\0'); p+=2, q+=2) {
wdenkc3f9d492004-03-14 00:59:59 +0000423 char tmp;
Wolfgang Denk389db1f2005-09-25 16:15:17 +0200424
425 tmp = *p;
426 *p = *q;
427 *q = tmp;
wdenkc3f9d492004-03-14 00:59:59 +0000428 }
429
430 return (char *) s;
431}
432#endif
433
wdenkc6097192002-11-03 00:24:07 +0000434#ifndef __HAVE_ARCH_MEMSET
435/**
436 * memset - Fill a region of memory with the given value
437 * @s: Pointer to the start of the area.
438 * @c: The byte to fill the area with
439 * @count: The size of the area.
440 *
441 * Do not use memset() to access IO space, use memset_io() instead.
442 */
443void * memset(void * s,int c,size_t count)
444{
Alessandro Rubinie3ea9482009-10-10 11:51:16 +0200445 unsigned long *sl = (unsigned long *) s;
446 unsigned long cl = 0;
447 char *s8;
448 int i;
wdenkc6097192002-11-03 00:24:07 +0000449
Alessandro Rubinie3ea9482009-10-10 11:51:16 +0200450 /* do it one word at a time (32 bits or 64 bits) while possible */
451 if ( ((ulong)s & (sizeof(*sl) - 1)) == 0) {
452 for (i = 0; i < sizeof(*sl); i++) {
453 cl <<= 8;
454 cl |= c & 0xff;
455 }
456 while (count >= sizeof(*sl)) {
457 *sl++ = cl;
458 count -= sizeof(*sl);
459 }
460 }
461 /* fill 8 bits at a time */
462 s8 = (char *)sl;
wdenkc6097192002-11-03 00:24:07 +0000463 while (count--)
Alessandro Rubinie3ea9482009-10-10 11:51:16 +0200464 *s8++ = c;
wdenkc6097192002-11-03 00:24:07 +0000465
466 return s;
467}
468#endif
469
470#ifndef __HAVE_ARCH_BCOPY
471/**
472 * bcopy - Copy one area of memory to another
473 * @src: Where to copy from
474 * @dest: Where to copy to
475 * @count: The size of the area.
476 *
477 * Note that this is the same as memcpy(), with the arguments reversed.
478 * memcpy() is the standard, bcopy() is a legacy BSD function.
479 *
480 * You should not use this function to access IO space, use memcpy_toio()
481 * or memcpy_fromio() instead.
482 */
483char * bcopy(const char * src, char * dest, int count)
484{
485 char *tmp = dest;
486
487 while (count--)
488 *tmp++ = *src++;
489
490 return dest;
491}
492#endif
493
494#ifndef __HAVE_ARCH_MEMCPY
495/**
496 * memcpy - Copy one area of memory to another
497 * @dest: Where to copy to
498 * @src: Where to copy from
499 * @count: The size of the area.
500 *
501 * You should not use this function to access IO space, use memcpy_toio()
502 * or memcpy_fromio() instead.
503 */
Alessandro Rubiniecd830b2009-10-10 11:51:05 +0200504void * memcpy(void *dest, const void *src, size_t count)
wdenkc6097192002-11-03 00:24:07 +0000505{
Alessandro Rubiniecd830b2009-10-10 11:51:05 +0200506 unsigned long *dl = (unsigned long *)dest, *sl = (unsigned long *)src;
507 char *d8, *s8;
wdenkc6097192002-11-03 00:24:07 +0000508
Matthias Weisserb038db82011-05-22 23:03:55 +0000509 if (src == dest)
510 return dest;
511
Alessandro Rubiniecd830b2009-10-10 11:51:05 +0200512 /* while all data is aligned (common case), copy a word at a time */
513 if ( (((ulong)dest | (ulong)src) & (sizeof(*dl) - 1)) == 0) {
514 while (count >= sizeof(*dl)) {
515 *dl++ = *sl++;
516 count -= sizeof(*dl);
517 }
518 }
519 /* copy the reset one byte at a time */
520 d8 = (char *)dl;
521 s8 = (char *)sl;
wdenkc6097192002-11-03 00:24:07 +0000522 while (count--)
Alessandro Rubiniecd830b2009-10-10 11:51:05 +0200523 *d8++ = *s8++;
wdenkc6097192002-11-03 00:24:07 +0000524
525 return dest;
526}
527#endif
528
529#ifndef __HAVE_ARCH_MEMMOVE
530/**
531 * memmove - Copy one area of memory to another
532 * @dest: Where to copy to
533 * @src: Where to copy from
534 * @count: The size of the area.
535 *
536 * Unlike memcpy(), memmove() copes with overlapping areas.
537 */
538void * memmove(void * dest,const void *src,size_t count)
539{
540 char *tmp, *s;
541
Matthias Weisserb038db82011-05-22 23:03:55 +0000542 if (src == dest)
543 return dest;
544
wdenkc6097192002-11-03 00:24:07 +0000545 if (dest <= src) {
546 tmp = (char *) dest;
547 s = (char *) src;
548 while (count--)
549 *tmp++ = *s++;
550 }
551 else {
552 tmp = (char *) dest + count;
553 s = (char *) src + count;
554 while (count--)
555 *--tmp = *--s;
556 }
557
558 return dest;
559}
560#endif
561
562#ifndef __HAVE_ARCH_MEMCMP
563/**
564 * memcmp - Compare two areas of memory
565 * @cs: One area of memory
566 * @ct: Another area of memory
567 * @count: The size of the area.
568 */
569int memcmp(const void * cs,const void * ct,size_t count)
570{
571 const unsigned char *su1, *su2;
572 int res = 0;
573
574 for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
575 if ((res = *su1 - *su2) != 0)
576 break;
577 return res;
578}
579#endif
580
581#ifndef __HAVE_ARCH_MEMSCAN
582/**
583 * memscan - Find a character in an area of memory.
584 * @addr: The memory area
585 * @c: The byte to search for
586 * @size: The size of the area.
587 *
588 * returns the address of the first occurrence of @c, or 1 byte past
589 * the area if @c is not found
590 */
591void * memscan(void * addr, int c, size_t size)
592{
593 unsigned char * p = (unsigned char *) addr;
594
595 while (size) {
596 if (*p == c)
597 return (void *) p;
598 p++;
599 size--;
600 }
wdenk8bde7f72003-06-27 21:31:46 +0000601 return (void *) p;
wdenkc6097192002-11-03 00:24:07 +0000602}
603#endif
604
605#ifndef __HAVE_ARCH_STRSTR
606/**
607 * strstr - Find the first substring in a %NUL terminated string
608 * @s1: The string to be searched
609 * @s2: The string to search for
610 */
611char * strstr(const char * s1,const char * s2)
612{
613 int l1, l2;
614
615 l2 = strlen(s2);
616 if (!l2)
617 return (char *) s1;
618 l1 = strlen(s1);
619 while (l1 >= l2) {
620 l1--;
621 if (!memcmp(s1,s2,l2))
622 return (char *) s1;
623 s1++;
624 }
625 return NULL;
626}
627#endif
628
629#ifndef __HAVE_ARCH_MEMCHR
630/**
631 * memchr - Find a character in an area of memory.
632 * @s: The memory area
633 * @c: The byte to search for
634 * @n: The size of the area.
635 *
636 * returns the address of the first occurrence of @c, or %NULL
637 * if @c is not found
638 */
639void *memchr(const void *s, int c, size_t n)
640{
641 const unsigned char *p = s;
642 while (n-- != 0) {
wdenk8bde7f72003-06-27 21:31:46 +0000643 if ((unsigned char)c == *p++) {
wdenkc6097192002-11-03 00:24:07 +0000644 return (void *)(p-1);
645 }
646 }
647 return NULL;
648}
649
650#endif