lib/string.c

   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
  14 #include <linux/types.h>
  15 #include <linux/string.h>
  16 #include <linux/ctype.h>
  17
  18 #ifndef __HAVE_ARCH_STRNICMP
  19 int strnicmp(const char *s1, const char *s2, size_t len)
  20 {
  21         /* Yes, Virginia, it had better be unsigned */
  22         unsigned char c1, c2;
  23
  24         c1 = 0; c2 = 0;
  25         if (len) {
  26                 do {
  27                         c1 = *s1; c2 = *s2;
  28                         s1++; s2++;
  29                         if (!c1)
  30                                 break;
  31                         if (!c2)
  32                                 break;
  33                         if (c1 == c2)
  34                                 continue;
  35                         c1 = tolower(c1);
  36                         c2 = tolower(c2);
  37                         if (c1 != c2)
  38                                 break;
  39                 } while (--len);
  40         }
  41         return (int)c1 - (int)c2;
  42 }
  43 #endif
  44
  45 char * ___strtok = NULL;
  46
  47 #ifndef __HAVE_ARCH_STRCPY
  48 char * strcpy(char * dest,const char *src)
  49 {
  50         char *tmp = dest;
  51
  52         while ((*dest++ = *src++) != '\0')
  53                 /* nothing */;
  54         return tmp;
  55 }
  56 #endif
  57
  58 #ifndef __HAVE_ARCH_STRNCPY
  59 char * strncpy(char * dest,const char *src,size_t count)
  60 {
  61         char *tmp = dest;
  62
  63         while (count-- && (*dest++ = *src++) != '\0')
  64                 /* nothing */;
  65
  66         return tmp;
  67 }
  68 #endif
  69
  70 #ifndef __HAVE_ARCH_STRCAT
  71 char * strcat(char * dest, const char * src)
  72 {
  73         char *tmp = dest;
  74
  75         while (*dest)
  76                 dest++;
  77         while ((*dest++ = *src++) != '\0')
  78                 ;
  79
  80         return tmp;
  81 }
  82 #endif
  83
  84 #ifndef __HAVE_ARCH_STRNCAT
  85 char * strncat(char *dest, const char *src, size_t count)
  86 {
  87         char *tmp = dest;
  88
  89         if (count) {
  90                 while (*dest)
  91                         dest++;
  92                 while ((*dest++ = *src++)) {
  93                         if (--count == 0) {
  94                                 *dest = '\0';
  95                                 break;
  96                         }
  97                 }
  98         }
  99
 100         return tmp;
 101 }
 102 #endif
 103
 104 #ifndef __HAVE_ARCH_STRCMP
 105 int strcmp(const char * cs,const char * ct)
 106 {
 107         register signed char __res;
 108
 109         while (1) {
 110                 if ((__res = *cs - *ct++) != 0 || !*cs++)
 111                         break;
 112         }
 113
 114         return __res;
 115 }
 116 #endif
 117
 118 #ifndef __HAVE_ARCH_STRNCMP
 119 int strncmp(const char * cs,const char * ct,size_t count)
 120 {
 121         register signed char __res = 0;
 122
 123         while (count) {
 124                 if ((__res = *cs - *ct++) != 0 || !*cs++)
 125                         break;
 126                 count--;
 127         }
 128
 129         return __res;
 130 }
 131 #endif
 132
 133 #ifndef __HAVE_ARCH_STRCHR
 134 char * strchr(const char * s, int c)
 135 {
 136         for(; *s != (char) c; ++s)
 137                 if (*s == '\0')
 138                         return NULL;
 139         return (char *) s;
 140 }
 141 #endif
 142
 143 #ifndef __HAVE_ARCH_STRRCHR
 144 char * strrchr(const char * s, int c)
 145 {
 146        const char *p = s + strlen(s);
 147        do {
 148            if (*p == (char)c)
 149                return (char *)p;
 150        } while (--p >= s);
 151        return NULL;
 152 }
 153 #endif
 154
 155 #ifndef __HAVE_ARCH_STRLEN
 156 size_t strlen(const char * s)
 157 {
 158         const char *sc;
 159
 160         for (sc = s; *sc != '\0'; ++sc)
 161                 /* nothing */;
 162         return sc - s;
 163 }
 164 #endif
 165
 166 #ifndef __HAVE_ARCH_STRNLEN
 167 size_t strnlen(const char * s, size_t count)
 168 {
 169         const char *sc;
 170
 171         for (sc = s; count-- && *sc != '\0'; ++sc)
 172                 /* nothing */;
 173         return sc - s;
 174 }
 175 #endif
 176
 177 #ifndef __HAVE_ARCH_STRSPN
 178 size_t strspn(const char *s, const char *accept)
 179 {
 180         const char *p;
 181         const char *a;
 182         size_t count = 0;
 183
 184         for (p = s; *p != '\0'; ++p) {
 185                 for (a = accept; *a != '\0'; ++a) {
 186                         if (*p == *a)
 187                                 break;
 188                 }
 189                 if (*a == '\0')
 190                         return count;
 191                 ++count;
 192         }
 193
 194         return count;
 195 }
 196 #endif
 197
 198 #ifndef __HAVE_ARCH_STRPBRK
 199 char * strpbrk(const char * cs,const char * ct)
 200 {
 201         const char *sc1,*sc2;
 202
 203         for( sc1 = cs; *sc1 != '\0'; ++sc1) {
 204                 for( sc2 = ct; *sc2 != '\0'; ++sc2) {
 205                         if (*sc1 == *sc2)
 206                                 return (char *) sc1;
 207                 }
 208         }
 209         return NULL;
 210 }
 211 #endif
 212
 213 #ifndef __HAVE_ARCH_STRTOK
 214 char * strtok(char * s,const char * ct)
 215 {
 216         char *sbegin, *send;
 217
 218         sbegin  = s ? s : ___strtok;
 219         if (!sbegin) {
 220                 return NULL;
 221         }
 222         sbegin += strspn(sbegin,ct);
 223         if (*sbegin == '\0') {
 224                 ___strtok = NULL;
 225                 return( NULL );
 226         }
 227         send = strpbrk( sbegin, ct);
 228         if (send && *send != '\0')
 229                 *send++ = '\0';
 230         ___strtok = send;
 231         return (sbegin);
 232 }
 233 #endif
 234
 235 #ifndef __HAVE_ARCH_MEMSET
 236 void * memset(void * s,char c,size_t count)
 237 {
 238         char *xs = (char *) s;
 239
 240         while (count--)
 241                 *xs++ = c;
 242
 243         return s;
 244 }
 245 #endif
 246
 247 #ifndef __HAVE_ARCH_BCOPY
 248 char * bcopy(const char * src, char * dest, int count)
 249 {
 250         char *tmp = dest;
 251
 252         while (count--)
 253                 *tmp++ = *src++;
 254
 255         return dest;
 256 }
 257 #endif
 258
 259 #ifndef __HAVE_ARCH_MEMCPY
 260 void * memcpy(void * dest,const void *src,size_t count)
 261 {
 262         char *tmp = (char *) dest, *s = (char *) src;
 263
 264         while (count--)
 265                 *tmp++ = *s++;
 266
 267         return dest;
 268 }
 269 #endif
 270
 271 #ifndef __HAVE_ARCH_MEMMOVE
 272 void * memmove(void * dest,const void *src,size_t count)
 273 {
 274         char *tmp, *s;
 275
 276         if (dest <= src) {
 277                 tmp = (char *) dest;
 278                 s = (char *) src;
 279                 while (count--)
 280                         *tmp++ = *s++;
 281                 }
 282         else {
 283                 tmp = (char *) dest + count;
 284                 s = (char *) src + count;
 285                 while (count--)
 286                         *--tmp = *--s;
 287                 }
 288
 289         return dest;
 290 }
 291 #endif
 292
 293 #ifndef __HAVE_ARCH_MEMCMP
 294 int memcmp(const void * cs,const void * ct,size_t count)
 295 {
 296         const unsigned char *su1, *su2;
 297         signed char res = 0;
 298
 299         for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
 300                 if ((res = *su1 - *su2) != 0)
 301                         break;
 302         return res;
 303 }
 304 #endif
 305
 306 /*
 307  * find the first occurrence of byte 'c', or 1 past the area if none
 308  */
 309 #ifndef __HAVE_ARCH_MEMSCAN
 310 void * memscan(void * addr, int c, size_t size)
 311 {
 312         unsigned char * p = (unsigned char *) addr;
 313
 314         while (size) {
 315                 if (*p == c)
 316                         return (void *) p;
 317                 p++;
 318                 size--;
 319         }
 320         return (void *) p;
 321 }
 322 #endif
 323
 324 #ifndef __HAVE_ARCH_STRSTR
 325 char * strstr(const char * s1,const char * s2)
 326 {
 327         int l1, l2;
 328
 329         l2 = strlen(s2);
 330         if (!l2)
 331                 return (char *) s1;
 332         l1 = strlen(s1);
 333         while (l1 >= l2) {
 334                 l1--;
 335                 if (!memcmp(s1,s2,l2))
 336                         return (char *) s1;
 337                 s1++;
 338         }
 339         return NULL;
 340 }
 341 #endif