1 /* 2 * libc string functions 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU Library General Public License version 2. 6 */ 7 8 #include "libcflat.h" 9 #include "stdlib.h" 10 #include "linux/compiler.h" 11 12 size_t strlen(const char *buf) 13 { 14 size_t len = 0; 15 16 while (*buf++) 17 ++len; 18 return len; 19 } 20 21 size_t strnlen(const char *buf, size_t maxlen) 22 { 23 const char *sc; 24 25 for (sc = buf; maxlen-- && *sc != '\0'; ++sc) 26 /* nothing */; 27 return sc - buf; 28 } 29 30 char *strcat(char *dest, const char *src) 31 { 32 char *p = dest; 33 34 while (*p) 35 ++p; 36 while ((*p++ = *src++) != 0) 37 ; 38 return dest; 39 } 40 41 char *strcpy(char *dest, const char *src) 42 { 43 *dest = 0; 44 return strcat(dest, src); 45 } 46 47 int strncmp(const char *a, const char *b, size_t n) 48 { 49 for (; n--; ++a, ++b) 50 if (*a != *b || *a == '\0') 51 return *a - *b; 52 53 return 0; 54 } 55 56 int strcmp(const char *a, const char *b) 57 { 58 return strncmp(a, b, SIZE_MAX); 59 } 60 61 char *strchr(const char *s, int c) 62 { 63 while (*s != (char)c) 64 if (*s++ == '\0') 65 return NULL; 66 return (char *)s; 67 } 68 69 char *strrchr(const char *s, int c) 70 { 71 const char *last = NULL; 72 do { 73 if (*s == (char)c) 74 last = s; 75 } while (*s++); 76 return (char *)last; 77 } 78 79 char *strchrnul(const char *s, int c) 80 { 81 while (*s && *s != (char)c) 82 s++; 83 return (char *)s; 84 } 85 86 char *strstr(const char *s1, const char *s2) 87 { 88 size_t l1, l2; 89 90 l2 = strlen(s2); 91 if (!l2) 92 return (char *)s1; 93 l1 = strlen(s1); 94 while (l1 >= l2) { 95 l1--; 96 if (!memcmp(s1, s2, l2)) 97 return (char *)s1; 98 s1++; 99 } 100 return NULL; 101 } 102 103 void *memset(void *s, int c, size_t n) 104 { 105 size_t i; 106 char *a = s; 107 108 for (i = 0; i < n; ++i) 109 a[i] = c; 110 111 return s; 112 } 113 114 void *memcpy(void *dest, const void *src, size_t n) 115 { 116 size_t i; 117 char *a = dest; 118 const char *b = src; 119 120 for (i = 0; i < n; ++i) 121 a[i] = b[i]; 122 123 return dest; 124 } 125 126 int memcmp(const void *s1, const void *s2, size_t n) 127 { 128 const unsigned char *a = s1, *b = s2; 129 int ret = 0; 130 131 while (n--) { 132 ret = *a - *b; 133 if (ret) 134 break; 135 ++a, ++b; 136 } 137 return ret; 138 } 139 140 void *memmove(void *dest, const void *src, size_t n) 141 { 142 const unsigned char *s = src; 143 unsigned char *d = dest; 144 145 if (d <= s) { 146 while (n--) 147 *d++ = *s++; 148 } else { 149 d += n, s += n; 150 while (n--) 151 *--d = *--s; 152 } 153 return dest; 154 } 155 156 void *memchr(const void *s, int c, size_t n) 157 { 158 const unsigned char *str = s, chr = (unsigned char)c; 159 160 while (n--) 161 if (*str++ == chr) 162 return (void *)(str - 1); 163 return NULL; 164 } 165 166 static int isspace(int c) 167 { 168 return c == ' ' || c == '\t' || c == '\r' || c == '\n' || c == '\v' || c == '\f'; 169 } 170 171 static unsigned long __strtol(const char *nptr, char **endptr, 172 int base, bool is_signed) { 173 unsigned long acc = 0; 174 const char *s = nptr; 175 int neg, c; 176 177 assert(base == 0 || (base >= 2 && base <= 36)); 178 179 while (isspace(*s)) 180 s++; 181 182 if (*s == '-') { 183 neg = 1; 184 s++; 185 } else { 186 neg = 0; 187 if (*s == '+') 188 s++; 189 } 190 191 if (base == 0 || base == 16) { 192 if (*s == '0') { 193 s++; 194 if (*s == 'x' || *s == 'X') { 195 s++; 196 base = 16; 197 } else if (base == 0) 198 base = 8; 199 } else if (base == 0) 200 base = 10; 201 } 202 203 while (*s) { 204 if (*s >= '0' && *s < '0' + base && *s <= '9') 205 c = *s - '0'; 206 else if (*s >= 'a' && *s < 'a' + base - 10) 207 c = *s - 'a' + 10; 208 else if (*s >= 'A' && *s < 'A' + base - 10) 209 c = *s - 'A' + 10; 210 else 211 break; 212 213 if (is_signed) { 214 long sacc = (long)acc; 215 assert(!check_mul_overflow(sacc, base)); 216 assert(!check_add_overflow(sacc * base, c)); 217 } else { 218 assert(!check_mul_overflow(acc, base)); 219 assert(!check_add_overflow(acc * base, c)); 220 } 221 222 acc = acc * base + c; 223 s++; 224 } 225 226 if (neg) 227 acc = -acc; 228 229 if (endptr) 230 *endptr = (char *)s; 231 232 return acc; 233 } 234 235 long int strtol(const char *nptr, char **endptr, int base) 236 { 237 return __strtol(nptr, endptr, base, true); 238 } 239 240 unsigned long int strtoul(const char *nptr, char **endptr, int base) 241 { 242 return __strtol(nptr, endptr, base, false); 243 } 244 245 long atol(const char *ptr) 246 { 247 return strtol(ptr, NULL, 10); 248 } 249 250 extern char **environ; 251 252 char *getenv(const char *name) 253 { 254 char **envp = environ, *delim; 255 int len; 256 257 while (*envp) { 258 delim = strchr(*envp, '='); 259 assert(delim); 260 len = delim - *envp; 261 if (memcmp(name, *envp, len) == 0 && !name[len]) 262 return delim + 1; 263 ++envp; 264 } 265 return NULL; 266 } 267 268 /* Very simple glob matching. Allows '*' at beginning and end of pattern. */ 269 bool simple_glob(const char *text, const char *pattern) 270 { 271 bool star_start = false; 272 bool star_end = false; 273 size_t n = strlen(pattern); 274 char copy[n + 1]; 275 276 if (pattern[0] == '*') { 277 pattern += 1; 278 n -= 1; 279 star_start = true; 280 } 281 282 strcpy(copy, pattern); 283 284 if (n > 0 && pattern[n - 1] == '*') { 285 n -= 1; 286 copy[n] = '\0'; 287 star_end = true; 288 } 289 290 if (star_start && star_end) 291 return strstr(text, copy); 292 293 if (star_end) 294 return strstr(text, copy) == text; 295 296 if (star_start) { 297 size_t text_len = strlen(text); 298 const char *suffix; 299 300 if (n > text_len) 301 return false; 302 suffix = text + text_len - n; 303 return !strcmp(suffix, copy); 304 } 305 306 return !strcmp(text, copy); 307 } 308