string.c
1 /* 2 * 3 * Copyright (C) 2007 Uwe Hermann <uwe@hermann-uwe.de> 4 * Copyright (C) 2008 Advanced Micro Devices, Inc. 5 * Copyright (C) 2010 coresystems GmbH 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <libpayload.h> 32 #include <string.h> 33 #include <ctype.h> 34 #include <inttypes.h> 35 #include <limits.h> 36 #include <errno.h> 37 38 /** 39 * Compare two strings. 40 * 41 * @param s1 The first string. 42 * @param s2 The second string. 43 * @return Returns a value less than zero, if s1 is shorter than s2. Returns 44 * zero, if s1 equals s2. Returns a value greater than zero, if 45 * s1 is longer than s2. 46 */ 47 int strcasecmp(const char *s1, const char *s2) 48 { 49 int res; 50 51 for (size_t i = 0; 1; i++) { 52 res = tolower(s1[i]) - tolower(s2[i]); 53 if (res || (s1[i] == '\0')) 54 break; 55 } 56 57 return res; 58 } 59 60 /** 61 * Compare two strings with fixed length. 62 * 63 * @param s1 The first string. 64 * @param s2 The second string. 65 * @param maxlen Return at most maxlen characters as length of the string. 66 * @return A non-zero value if s1 and s2 differ, or zero if s1 equals s2. 67 */ 68 int strncasecmp(const char *s1, const char *s2, size_t maxlen) 69 { 70 int res = 0; 71 72 for (size_t i = 0; i < maxlen; i++) { 73 res = tolower(s1[i]) - tolower(s2[i]); 74 if (res || (s1[i] == '\0')) 75 break; 76 } 77 78 return res; 79 } 80 81 /** 82 * Compare two strings. 83 * 84 * @param s1 The first string. 85 * @param s2 The second string. 86 * @return Returns a value less than zero, if s1 is shorter than s2. Returns 87 * zero, if s1 equals s2. Returns a value greater than zero, if 88 * s1 is longer than s2. 89 */ 90 int strcmp(const char *s1, const char *s2) 91 { 92 int res; 93 94 for (size_t i = 0; 1; i++) { 95 res = s1[i] - s2[i]; 96 if (res || (s1[i] == '\0')) 97 break; 98 } 99 100 return res; 101 } 102 103 /** 104 * Compare two strings with fixed length. 105 * 106 * @param s1 The first string. 107 * @param s2 The second string. 108 * @param maxlen Return at most maxlen characters as length of the string. 109 * @return A non-zero value if s1 and s2 differ, or zero if s1 equals s2. 110 */ 111 int strncmp(const char *s1, const char *s2, size_t maxlen) 112 { 113 int res = 0; 114 115 for (size_t i = 0; i < maxlen; i++) { 116 res = s1[i] - s2[i]; 117 if (res || (s1[i] == '\0')) 118 break; 119 } 120 121 return res; 122 } 123 124 /** 125 * Copy a string with a maximum length. 126 * 127 * @param d The destination memory. 128 * @param s The source string. 129 * @param n Copy at most n characters as length of the string. 130 * @return A pointer to the destination memory. 131 */ 132 char *strncpy(char *d, const char *s, size_t n) 133 { 134 /* Use +1 to get the NUL terminator. */ 135 size_t max = n > strlen(s) + 1 ? strlen(s) + 1 : n; 136 137 for (size_t i = 0; i < max; i++) 138 d[i] = (char)s[i]; 139 140 return d; 141 } 142 143 /** 144 * Copy a string. 145 * 146 * @param d The destination memory. 147 * @param s The source string. 148 * @return A pointer to the destination memory. 149 */ 150 char *strcpy(char *d, const char *s) 151 { 152 return strncpy(d, s, strlen(s) + 1); 153 } 154 155 /** 156 * Concatenates two strings with a maximum length. 157 * 158 * @param d The destination string. 159 * @param s The source string. 160 * @param n d will have at most n-1 characters (plus NUL) after invocation. 161 * @return The total length of the concatenated string. 162 */ 163 size_t strlcat(char *d, const char *s, size_t n) 164 { 165 size_t sl = strlen(s); 166 size_t dl = strlen(d); 167 168 if (n <= dl + 1) 169 return sl + dl; 170 171 char *p = d + dl; 172 size_t max = n > (sl + dl) ? sl : (n - dl - 1); 173 174 for (size_t i = 0; i < max; i++) 175 p[i] = s[i]; 176 177 p[max] = '\0'; 178 return sl + dl; 179 } 180 181 /** 182 * Find a character in a string. 183 * 184 * @param s The string. 185 * @param c The character. 186 * @return A pointer to the first occurrence of the character in the 187 * string, or NULL if the character was not encountered within the string. 188 */ 189 char *strchr(const char *s, int c) 190 { 191 char *p = (char *)s; 192 193 for (; *p != 0; p++) { 194 if (*p == c) 195 return p; 196 } 197 198 return NULL; 199 } 200 201 /** 202 * Find a character in a string. 203 * 204 * @param s The string. 205 * @param c The character. 206 * @return A pointer to the last occurrence of the character in the 207 * string, or NULL if the character was not encountered within the string. 208 */ 209 210 char *strrchr(const char *s, int c) 211 { 212 char *p = (char *)s + strlen(s); 213 214 for (; p >= s; p--) { 215 if (*p == c) 216 return p; 217 } 218 219 return NULL; 220 } 221 222 /** 223 * Duplicate a string. 224 * 225 * @param s The string to duplicate. 226 * @return A pointer to the copy of the original string. 227 */ 228 char *strdup(const char *s) 229 { 230 size_t n = strlen(s); 231 char *p = malloc(n + 1); 232 233 if (p != NULL) { 234 strncpy(p, s, n); 235 p[n] = 0; 236 } 237 return p; 238 } 239 240 /** 241 * Duplicate a string with a max length of size 242 * 243 * @param s The string to duplicate. 244 * @param size The max length of the string 245 * @return A pointer to the copy of the original string. 246 */ 247 char *strndup(const char *s, size_t size) 248 { 249 size_t n = strnlen(s, size); 250 char *p = malloc(n + 1); 251 252 if (p != NULL) { 253 strncpy(p, s, n); 254 p[n] = 0; 255 } 256 return p; 257 } 258 259 /** 260 * Find a substring within a string. 261 * 262 * @param h The haystack string. 263 * @param n The needle string (substring). 264 * @return A pointer to the first occurrence of the substring in 265 * the string, or NULL if the substring was not encountered within the string. 266 */ 267 char *strstr(const char *h, const char *n) 268 { 269 size_t hn = strlen(h); 270 size_t nn = strlen(n); 271 272 if (hn < nn) 273 return NULL; 274 275 for (size_t i = 0; i <= hn - nn; i++) 276 if (!memcmp(&h[i], n, nn)) 277 return (char *)&h[i]; 278 279 return NULL; 280 } 281 282 /** 283 * Separate strings. 284 * 285 * @param stringp reference of the string to separate. 286 * @param delim string containing all delimiters. 287 * @return Token string. 288 */ 289 char *strsep(char **stringp, const char *delim) 290 { 291 char *walk, *token; 292 293 if (!stringp || !*stringp || !**stringp) 294 return NULL; 295 296 token = walk = *stringp; 297 298 /* Walk, search for delimiters */ 299 while (*walk && !strchr(delim, *walk)) 300 walk++; 301 302 if (*walk) { 303 /* NUL terminate */ 304 *walk = '\0'; 305 walk++; 306 } 307 308 *stringp = walk; 309 310 return token; 311 } 312 313 /* Check that a character is in the valid range for the 314 given base 315 */ 316 317 static int _valid(char ch, int base) 318 { 319 char end = (base > 9) ? '9' : '0' + (base - 1); 320 321 /* all bases will be some subset of the 0-9 range */ 322 323 if (ch >= '0' && ch <= end) 324 return 1; 325 326 /* Bases > 11 will also have to match in the a-z range */ 327 328 if (base > 11) { 329 if (tolower(ch) >= 'a' && 330 tolower(ch) <= 'a' + (base - 11)) 331 return 1; 332 } 333 334 return 0; 335 } 336 337 /* Return the "value" of the character in the given base */ 338 339 static int _offset(char ch, int base) 340 { 341 if (ch >= '0' && ch <= '9') 342 return ch - '0'; 343 else 344 return 10 + tolower(ch) - 'a'; 345 } 346 347 /** 348 * Convert the initial portion of a string into a signed int 349 * @param ptr A pointer to the string to convert 350 * @param endptr A pointer to the unconverted part of the string 351 * @param base The base of the number to convert, or 0 for auto 352 * @return A signed integer representation of the string 353 */ 354 355 long long int strtoll(const char *orig_ptr, char **endptr, int base) 356 { 357 const char *ptr = orig_ptr; 358 int is_negative = 0; 359 360 /* Purge whitespace */ 361 362 for ( ; *ptr && isspace(*ptr); ptr++); 363 364 if (ptr[0] == '-') { 365 is_negative = 1; 366 ptr++; 367 } 368 369 unsigned long long uval = strtoull(ptr, endptr, base); 370 371 /* If the whole string is unparseable, endptr should point to start. */ 372 if (endptr && *endptr == ptr) 373 *endptr = (char *)orig_ptr; 374 375 if (uval > (unsigned long long)LLONG_MAX + !!is_negative) 376 uval = (unsigned long long)LLONG_MAX + !!is_negative; 377 378 if (is_negative) 379 return -uval; 380 else 381 return uval; 382 } 383 384 long int strtol(const char *ptr, char **endptr, int base) 385 { 386 long long int val = strtoll(ptr, endptr, base); 387 if (val > LONG_MAX) 388 return LONG_MAX; 389 if (val < LONG_MIN) 390 return LONG_MIN; 391 return val; 392 } 393 394 long atol(const char *nptr) 395 { 396 return strtol(nptr, NULL, 10); 397 } 398 399 /** 400 * Convert the initial portion of a string into an unsigned int 401 * @param ptr A pointer to the string to convert 402 * @param endptr A pointer to the unconverted part of the string 403 * @param base The base of the number to convert, or 0 for auto 404 * @return An unsigned integer representation of the string 405 */ 406 407 unsigned long long int strtoull(const char *ptr, char **endptr, int base) 408 { 409 unsigned long long int ret = 0; 410 411 if (endptr != NULL) 412 *endptr = (char *) ptr; 413 414 /* Purge whitespace */ 415 416 for ( ; *ptr && isspace(*ptr); ptr++); 417 418 if (!*ptr) 419 return 0; 420 421 /* Determine the base */ 422 423 if (base == 0) { 424 if (ptr[0] == '0' && (ptr[1] == 'x' || ptr[1] == 'X')) 425 base = 16; 426 else if (ptr[0] == '0') { 427 base = 8; 428 ptr++; 429 } else { 430 base = 10; 431 } 432 } 433 434 /* Base 16 allows the 0x on front - so skip over it */ 435 436 if (base == 16) { 437 if (ptr[0] == '0' && (ptr[1] == 'x' || ptr[1] == 'X') && 438 _valid(ptr[2], base)) 439 ptr += 2; 440 } 441 442 for ( ; *ptr && _valid(*ptr, base); ptr++) 443 ret = (ret * base) + _offset(*ptr, base); 444 445 if (endptr != NULL) 446 *endptr = (char *) ptr; 447 448 return ret; 449 } 450 451 unsigned long int strtoul(const char *ptr, char **endptr, int base) 452 { 453 unsigned long long val = strtoull(ptr, endptr, base); 454 if (val > ULONG_MAX) 455 return ULONG_MAX; 456 return val; 457 } 458 459 /** 460 * Determine the number of leading characters in s that match characters in a 461 * @param s A pointer to the string to analyse 462 * @param a A pointer to an array of characters that match the prefix 463 * @return The number of matching characters 464 */ 465 size_t strspn(const char *s, const char *a) 466 { 467 size_t i; 468 size_t al = strlen(a); 469 for (i = 0; s[i] != 0; i++) { 470 int found = 0; 471 for (size_t j = 0; j < al; j++) { 472 if (s[i] == a[j]) { 473 found = 1; 474 break; 475 } 476 } 477 if (!found) 478 break; 479 } 480 return i; 481 } 482 483 /** 484 * Determine the number of leading characters in s that do not match characters in a 485 * @param s A pointer to the string to analyse 486 * @param a A pointer to an array of characters that do not match the prefix 487 * @return The number of not matching characters 488 */ 489 size_t strcspn(const char *s, const char *a) 490 { 491 size_t i; 492 size_t al = strlen(a); 493 for (i = 0; s[i] != 0; i++) { 494 int found = 0; 495 for (size_t j = 0; j < al; j++) { 496 if (s[i] == a[j]) { 497 found = 1; 498 break; 499 } 500 } 501 if (found) 502 break; 503 } 504 return i; 505 } 506 507 /** 508 * Extract first token in string str that is delimited by a character in tokens. 509 * Destroys str and eliminates the token delimiter. 510 * @param str A pointer to the string to tokenize. 511 * @param delim A pointer to an array of characters that delimit the token 512 * @param ptr A pointer to a string pointer to keep state of the tokenizer 513 * @return Pointer to token 514 */ 515 char *strtok_r(char *str, const char *delim, char **ptr) 516 { 517 /* start new tokenizing job or continue existing one? */ 518 if (str == NULL) 519 str = *ptr; 520 521 /* skip over prefix delimiters */ 522 char *start = str + strspn(str, delim); 523 524 if (start[0] == '\0') 525 return NULL; 526 527 /* find first delimiter character */ 528 char *end = start + strcspn(start, delim); 529 *ptr = end; 530 if (end[0] != '\0') 531 *(*ptr)++ = '\0'; 532 533 return start; 534 } 535 536 /** 537 * Extract first token in string str that is delimited by a character in tokens. 538 * Destroys str, eliminates the token delimiter and uses global state. 539 * @param str A pointer to the string to tokenize. 540 * @param delim A pointer to an array of characters that delimit the token 541 * @return Pointer to token 542 */ 543 char *strtok(char *str, const char *delim) 544 { 545 static char *strtok_ptr; 546 547 return strtok_r(str, delim, &strtok_ptr); 548 } 549 550 /** 551 * Print error message and error number 552 * @param s Error message to print 553 */ 554 void perror(const char *s) 555 { 556 printf("%s: %d\n", s?s:"(none)", errno); 557 } 558 559 /** 560 * Get a message string describing the given error number. 561 * 562 * @param errnum The error number to be interpreted 563 * @return A pointer to a string describing the given error number 564 */ 565 char *strerror(int errnum) 566 { 567 /* Reserve enough space for the string below + INT64_MIN in decimal + \0 */ 568 static char errstr[35]; 569 snprintf(errstr, sizeof(errstr), "Unknown error %d", errnum); 570 return errstr; 571 } 572 573 /* 574 * Simple routine to convert UTF-16 to ASCII, giving up with ? if too high. 575 * A single code point may convert to ?? if not in the BMP. 576 * @param utf16_string A string encoded in UTF-16LE 577 * @param maxlen Maximum possible length of the string in code points 578 * @return Newly allocated ASCII string 579 */ 580 char *utf16le_to_ascii(const uint16_t *utf16_string, size_t maxlen) 581 { 582 char *ascii_string = xmalloc(maxlen + 1); /* +1 for trailing \0 */ 583 ascii_string[maxlen] = '\0'; 584 for (size_t i = 0; i < maxlen; i++) { 585 uint16_t wchar = utf16_string[i]; 586 ascii_string[i] = wchar > 0x7f ? '?' : (char)wchar; 587 } 588 return ascii_string; 589 }