reactos/ntoskrnl/rtl/string.c

   1 /*
   2  * COPYRIGHT:       See COPYING in the top level directory
   3  * PROJECT:         ReactOS kernel
   4  * FILE:            ntoskrnl/rtl/string.c
   5  * PURPOSE:         Ascii string functions
   6  * PROGRAMMER:      Eric Kohl (ekohl@abo.rhein-zeitung.de)
   7  * UPDATE HISTORY:
   8  *   1999/07/29  ekohl   Created
   9  */
  10
  11 /* INCLUDES *****************************************************************/
  12
  13 #include <ctype.h>
  14 #include <string.h>
  15
  16 /* FUNCTIONS *****************************************************************/
  17
  18 int _stricmp(const char *s1, const char *s2)
  19 {
  20         while (toupper(*s1) == toupper(*s2))
  21         {
  22                 if (*s1 == 0)
  23                         return 0;
  24                 s1++;
  25                 s2++;
  26         }
  27         return toupper(*(unsigned const char *)s1) - toupper(*(unsigned const char *)(s2));
  28 }
  29
  30
  31 char * _strlwr(char *x)
  32 {
  33         char  *y=x;
  34
  35         while (*y)
  36         {
  37                 *y=tolower(*y);
  38                 y++;
  39         }
  40         return x;
  41 }
  42
  43
  44 int _strnicmp(const char *s1, const char *s2, size_t n)
  45 {
  46         if (n == 0)
  47                 return 0;
  48         do
  49         {
  50                 if (toupper(*s1) != toupper(*s2++))
  51                         return toupper(*(unsigned const char *)s1) - toupper(*(unsigned const char *)--s2);
  52                 if (*s1++ == 0)
  53                         break;
  54         }
  55         while (--n != 0);
  56         return 0;
  57 }
  58
  59 char* _strnset(char* szToFill, int szFill, size_t sizeMaxFill)
  60 {
  61         char *t = szToFill;
  62         int i = 0;
  63         while (*szToFill != 0 && i < sizeMaxFill)
  64         {
  65                 *szToFill = szFill;
  66                 szToFill++;
  67                 i++;
  68
  69         }
  70         return t;
  71 }
  72
  73
  74 char * _strrev(char *s)
  75 {
  76         char  *e;
  77         char   a;
  78
  79         e = s;
  80         while (*e)
  81                 e++;
  82
  83         while (s<e)
  84         {
  85                 a = *s;
  86                 *s = *e;
  87                 *e = a;
  88                 s++;
  89                 e--;
  90         }
  91         return s;
  92 }
  93
  94
  95 char* _strset(char* szToFill, int szFill)
  96 {
  97         char *t = szToFill;
  98         while (*szToFill != 0)
  99         {
 100                 *szToFill = szFill;
 101                 szToFill++;
 102
 103         }
 104         return t;
 105 }
 106
 107
 108 char *_strupr(char *x)
 109 {
 110         char  *y=x;
 111
 112         while (*y)
 113         {
 114                 *y=toupper(*y);
 115                 y++;
 116         }
 117         return x;
 118 }
 119
 120
 121 char *strcat(char *s, const char *append)
 122 {
 123         char *save = s;
 124
 125         for (; *s; ++s);
 126         while ((*s++ = *append++));
 127         return save;
 128 }
 129
 130
 131 char *strchr(const char *s, int c)
 132 {
 133         char cc = c;
 134
 135         while (*s)
 136         {
 137                 if (*s == cc)
 138                         return (char *)s;
 139                 s++;
 140         }
 141
 142         if (cc == 0)
 143                 return (char *)s;
 144
 145         return 0;
 146 }
 147
 148
 149 int strcmp(const char *s1, const char *s2)
 150 {
 151         while (*s1 == *s2)
 152         {
 153                 if (*s1 == 0)
 154                         return 0;
 155                 s1++;
 156                 s2++;
 157         }
 158
 159         return *(unsigned const char *)s1 - *(unsigned const char *)(s2);
 160 }
 161
 162
 163 char* strcpy(char *to, const char *from)
 164 {
 165         char *save = to;
 166
 167         for (; (*to = *from); ++from, ++to);
 168
 169         return save;
 170 }
 171
 172
 173 size_t strlen(const char *str)
 174 {
 175         const char *s;
 176
 177         if (str == 0)
 178                 return 0;
 179         for (s = str; *s; ++s);
 180
 181         return s-str;
 182 }
 183
 184
 185 char *strncat(char *dst, const char *src, size_t n)
 186 {
 187         if (n != 0)
 188         {
 189                 char *d = dst;
 190                 const char *s = src;
 191
 192                 while (*d != 0)
 193                         d++;
 194                 do
 195                 {
 196                         if ((*d = *s++) == 0)
 197                                 break;
 198                         d++;
 199                 }
 200                 while (--n != 0);
 201                 *d = 0;
 202         }
 203
 204         return dst;
 205 }
 206
 207
 208 int strncmp(const char *s1, const char *s2, size_t n)
 209 {
 210         if (n == 0)
 211                 return 0;
 212         do
 213         {
 214                 if (*s1 != *s2++)
 215                         return *(unsigned const char *)s1 - *(unsigned const char *)--s2;
 216                 if (*s1++ == 0)
 217                         break;
 218         }
 219         while (--n != 0);
 220
 221         return 0;
 222 }
 223
 224
 225 char *strncpy(char *dst, const char *src, size_t n)
 226 {
 227         if (n != 0)
 228         {
 229                 char *d = dst;
 230                 const char *s = src;
 231
 232                 do
 233                 {
 234                         if ((*d++ = *s++) == 0)
 235                         {
 236                                 while (--n != 0)
 237                                         *d++ = 0;
 238                                 break;
 239                         }
 240                 }
 241                 while (--n != 0);
 242         }
 243
 244         return dst;
 245 }
 246
 247
 248 char *strrchr(const char *s, int c)
 249 {
 250         char cc = c;
 251         const char *sp=(char *)0;
 252
 253         while (*s)
 254         {
 255                 if (*s == cc)
 256                         sp = s;
 257                 s++;
 258         }
 259
 260         if (cc == 0)
 261                 sp = s;
 262
 263         return (char *)sp;
 264 }
 265
 266
 267 size_t strspn(const char *s1, const char *s2)
 268 {
 269         const char *p = s1, *spanp;
 270         char c, sc;
 271
 272   cont:
 273         c = *p++;
 274         for (spanp = s2; (sc = *spanp++) != 0;)
 275                 if (sc == c)
 276                         goto cont;
 277
 278         return (p - 1 - s1);
 279 }
 280
 281
 282 char *strstr(const char *s, const char *find)
 283 {
 284         char c, sc;
 285         size_t len;
 286
 287         if ((c = *find++) != 0)
 288         {
 289                 len = strlen(find);
 290                 do
 291                 {
 292                         do
 293                         {
 294                                 if ((sc = *s++) == 0)
 295                                         return 0;
 296                         }
 297                         while (sc != c);
 298                 }
 299                 while (strncmp(s, find, len) != 0);
 300                 s--;
 301         }
 302
 303         return (char *)s;
 304 }