string.c 3.8 KB

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  1. /*
  2. * aboot/lib/string.c
  3. *
  4. * Copyright (C) 1991, 1992 Linus Torvalds
  5. */
  6. /*
  7. * stupid library routines.. The optimized versions should generally be found
  8. * as inline code in <asm-xx/string.h>
  9. *
  10. * These are buggy as well..
  11. */
  12. #include <stddef.h>
  13. #include <linux/types.h>
  14. char * ___strtok = NULL;
  15. char * strcpy(char * dest,const char *src)
  16. {
  17. char *tmp = dest;
  18. while ((*dest++ = *src++) != '\0')
  19. /* nothing */;
  20. return tmp;
  21. }
  22. char * strncpy(char * dest,const char *src,size_t count)
  23. {
  24. char *tmp = dest;
  25. while (count-- && (*dest++ = *src++) != '\0')
  26. /* nothing */;
  27. return tmp;
  28. }
  29. char * strcat(char * dest, const char * src)
  30. {
  31. char *tmp = dest;
  32. while (*dest)
  33. dest++;
  34. while ((*dest++ = *src++) != '\0')
  35. ;
  36. return tmp;
  37. }
  38. char * strncat(char *dest, const char *src, size_t count)
  39. {
  40. char *tmp = dest;
  41. if (count) {
  42. while (*dest)
  43. dest++;
  44. while ((*dest++ = *src++)) {
  45. if (--count == 0)
  46. break;
  47. }
  48. }
  49. return tmp;
  50. }
  51. int strcmp(const char * cs,const char * ct)
  52. {
  53. register signed char __res;
  54. while (1) {
  55. if ((__res = *cs - *ct++) != 0 || !*cs++)
  56. break;
  57. }
  58. return __res;
  59. }
  60. int strncmp(const char * cs,const char * ct,size_t count)
  61. {
  62. register signed char __res = 0;
  63. while (count) {
  64. if ((__res = *cs - *ct++) != 0 || !*cs++)
  65. break;
  66. count--;
  67. }
  68. return __res;
  69. }
  70. char * strchr(const char * s,char c)
  71. {
  72. for(; *s != c; ++s)
  73. if (*s == '\0')
  74. return NULL;
  75. return (char *) s;
  76. }
  77. char * strrchr(const char * s,char c)
  78. {
  79. const char * r = NULL;
  80. while (*s++)
  81. if (*s == c) r = s;
  82. return (char *) r;
  83. }
  84. size_t strlen(const char * s)
  85. {
  86. const char *sc;
  87. for (sc = s; *sc != '\0'; ++sc)
  88. /* nothing */;
  89. return sc - s;
  90. }
  91. size_t strnlen(const char * s, size_t count)
  92. {
  93. const char *sc;
  94. for (sc = s; *sc != '\0' && count--; ++sc)
  95. /* nothing */;
  96. return sc - s;
  97. }
  98. size_t strspn(const char *s, const char *accept)
  99. {
  100. const char *p;
  101. const char *a;
  102. size_t count = 0;
  103. for (p = s; *p != '\0'; ++p) {
  104. for (a = accept; *a != '\0'; ++a) {
  105. if (*p == *a)
  106. break;
  107. }
  108. if (*a == '\0')
  109. return count;
  110. ++count;
  111. }
  112. return count;
  113. }
  114. char * strpbrk(const char * cs,const char * ct)
  115. {
  116. const char *sc1,*sc2;
  117. for( sc1 = cs; *sc1 != '\0'; ++sc1) {
  118. for( sc2 = ct; *sc2 != '\0'; ++sc2) {
  119. if (*sc1 == *sc2)
  120. return (char *) sc1;
  121. }
  122. }
  123. return NULL;
  124. }
  125. char * strtok(char * s,const char * ct)
  126. {
  127. char *sbegin, *send;
  128. sbegin = s ? s : ___strtok;
  129. if (!sbegin) {
  130. return NULL;
  131. }
  132. sbegin += strspn(sbegin,ct);
  133. if (*sbegin == '\0') {
  134. ___strtok = NULL;
  135. return( NULL );
  136. }
  137. send = strpbrk( sbegin, ct);
  138. if (send && *send != '\0')
  139. *send++ = '\0';
  140. ___strtok = send;
  141. return (sbegin);
  142. }
  143. void * memset(void * s, int c, size_t count)
  144. {
  145. char *xs = (char *) s;
  146. while (count--)
  147. *xs++ = c;
  148. return s;
  149. }
  150. char * bcopy(const char * src, char * dest, int count)
  151. {
  152. char *tmp = dest;
  153. while (count--)
  154. *tmp++ = *src++;
  155. return dest;
  156. }
  157. void * memcpy(void * dest,const void *src,size_t count)
  158. {
  159. char *tmp = (char *) dest, *s = (char *) src;
  160. while (count--)
  161. *tmp++ = *s++;
  162. return dest;
  163. }
  164. void * memmove(void * dest,const void *src,size_t count)
  165. {
  166. char *tmp, *s;
  167. if (dest <= src) {
  168. tmp = (char *) dest;
  169. s = (char *) src;
  170. while (count--)
  171. *tmp++ = *s++;
  172. }
  173. else {
  174. tmp = (char *) dest + count;
  175. s = (char *) src + count;
  176. while (count--)
  177. *--tmp = *--s;
  178. }
  179. return dest;
  180. }
  181. int memcmp(const void * cs,const void * ct,size_t count)
  182. {
  183. const unsigned char *su1, *su2;
  184. signed char res = 0;
  185. for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
  186. if ((res = *su1 - *su2) != 0)
  187. break;
  188. return res;
  189. }
  190. /*
  191. * find the first occurrence of byte 'c', or 1 past the area if none
  192. */
  193. void * memscan(void * addr, unsigned char c, size_t size)
  194. {
  195. unsigned char * p = (unsigned char *) addr;
  196. while (size) {
  197. if (*p == c)
  198. return (void *) p;
  199. p++;
  200. size--;
  201. }
  202. return (void *) p;
  203. }