str.c 13 KB

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  1. /** @file str.c
  2. * @brief String related functions
  3. *
  4. * This file implements some often used string functions.
  5. * Some functions are more portable versions of standard
  6. * functions but others are original ones.
  7. */
  8. #include <stdlib.h>
  9. #include <string.h>
  10. #include <assert.h>
  11. #include <stdio.h>
  12. #include "faux/ctype.h"
  13. #include "faux/str.h"
  14. /* TODO: Are that vars really needed? */
  15. //const char *lub_string_esc_default = "`|$<>&()#;\\\"!";
  16. //const char *lub_string_esc_regex = "^$.*+[](){}";
  17. //const char *lub_string_esc_quoted = "\\\"";
  18. /** @brief Free the memory allocated for the string.
  19. *
  20. * Safely free the memory allocated for the string. You can use NULL
  21. * pointer with this function. POSIX's free() checks for the NULL pointer
  22. * but not all systems do so.
  23. *
  24. * @param [in] str String to free
  25. */
  26. void faux_str_free(char *str) {
  27. faux_free(str);
  28. }
  29. /** @brief Duplicates the string.
  30. *
  31. * Duplicates the string. Same as standard strdup() function. Allocates
  32. * memory with malloc(). Checks for NULL pointer.
  33. *
  34. * @warning Resulting string must be freed by faux_str_free().
  35. *
  36. * @param [in] str String to duplicate.
  37. * @return Pointer to allocated string or NULL.
  38. */
  39. char *faux_str_dup(const char *str) {
  40. if (!str)
  41. return NULL;
  42. return strdup(str);
  43. }
  44. /** @brief Duplicates the first n bytes of the string.
  45. *
  46. * Duplicates at most n bytes of the string. Allocates
  47. * memory with malloc(). Checks for NULL pointer. Function will allocate
  48. * n + 1 bytes to store string and terminating null byte.
  49. *
  50. * @warning Resulting string must be freed by faux_str_free().
  51. *
  52. * @param [in] str String to duplicate.
  53. * @param [in] n Number of bytes to copy.
  54. * @return Pointer to allocated string or NULL.
  55. */
  56. char *faux_str_dupn(const char *str, size_t n) {
  57. char *res = NULL;
  58. size_t len = 0;
  59. if (!str)
  60. return NULL;
  61. len = strlen(str);
  62. len = (len < n) ? len : n;
  63. res = faux_zmalloc(len + 1);
  64. if (!res)
  65. return NULL;
  66. strncpy(res, str, len);
  67. res[len] = '\0';
  68. return res;
  69. }
  70. /** @brief Generates lowercase copy of input string.
  71. *
  72. * Allocates the copy of input string and convert that copy to lowercase.
  73. *
  74. * @warning Resulting string must be freed by faux_str_free().
  75. *
  76. * @param [in] str String to convert.
  77. * @return Pointer to lowercase string copy or NULL.
  78. */
  79. char *faux_str_tolower(const char *str) {
  80. char *res = faux_str_dup(str);
  81. char *p = res;
  82. if (!res)
  83. return NULL;
  84. while (*p) {
  85. *p = faux_ctype_tolower(*p);
  86. p++;
  87. }
  88. return res;
  89. }
  90. /** @brief Generates uppercase copy of input string.
  91. *
  92. * Allocates the copy of input string and convert that copy to uppercase.
  93. *
  94. * @warning Resulting string must be freed by faux_str_free().
  95. *
  96. * @param [in] str String to convert.
  97. * @return Pointer to lowercase string copy or NULL.
  98. */
  99. char *faux_str_toupper(const char *str) {
  100. char *res = faux_str_dup(str);
  101. char *p = res;
  102. if (!res)
  103. return NULL;
  104. while (*p) {
  105. *p = faux_ctype_toupper(*p);
  106. p++;
  107. }
  108. return res;
  109. }
  110. /** @brief Add n bytes of text to existent string.
  111. *
  112. * Concatenate two strings. Add n bytes of second string to the end of the
  113. * first one. The first argument is address of string pointer. The pointer
  114. * can be changed due to realloc() features. The first pointer can be NULL.
  115. * In this case the memory will be malloc()-ed and stored to the first pointer.
  116. *
  117. * @param [in,out] str Address of first string pointer.
  118. * @param [in] text Text to add to the first string.
  119. * @param [in] n Number of bytes to add.
  120. * @return Pointer to resulting string or NULL.
  121. */
  122. char *faux_str_catn(char **str, const char *text, size_t n) {
  123. size_t str_len = 0;
  124. size_t text_len = 0;
  125. char *res = NULL;
  126. char *p = NULL;
  127. if (!text)
  128. return *str;
  129. str_len = (*str) ? strlen(*str) : 0;
  130. text_len = strlen(text);
  131. text_len = (text_len < n) ? text_len : n;
  132. res = realloc(*str, str_len + text_len + 1);
  133. if (!res)
  134. return NULL;
  135. p = res + str_len;
  136. strncpy(p, text, text_len);
  137. p[text_len] = '\0';
  138. *str = res;
  139. return res;
  140. }
  141. /** @brief Add some text to existent string.
  142. *
  143. * Concatenate two strings. Add second string to the end of the first one.
  144. * The first argument is address of string pointer. The pointer can be
  145. * changed due to realloc() features. The first pointer can be NULL. In this
  146. * case the memory will be malloc()-ed and stored to the first pointer.
  147. *
  148. * @param [in,out] str Address of first string pointer.
  149. * @param [in] text Text to add to the first string.
  150. * @return Pointer to resulting string or NULL.
  151. */
  152. char *faux_str_cat(char **str, const char *text) {
  153. size_t len = 0;
  154. if (!text)
  155. return *str;
  156. len = strlen(text);
  157. return faux_str_catn(str, text, len);
  158. }
  159. /** @brief Service function to compare to chars in right way.
  160. *
  161. * The problem is char type can be signed or unsigned on different
  162. * platforms. So stright comparision can return different results.
  163. *
  164. * @param [in] char1 First char
  165. * @param [in] char2 Second char
  166. * @return
  167. * < 0 if char1 < char2
  168. * = 0 if char1 = char2
  169. * > 0 if char1 > char2
  170. */
  171. static int faux_str_cmp_chars(char char1, char char2) {
  172. unsigned char ch1 = (unsigned char)char1;
  173. unsigned char ch2 = (unsigned char)char2;
  174. return (int)ch1 - (int)ch2;
  175. }
  176. /** @brief Compare n first characters of two strings ignoring case.
  177. *
  178. * The difference beetween this function an standard strncasecmp() is
  179. * faux function uses faux ctype functions. It can be important for
  180. * portability.
  181. *
  182. * @param [in] str1 First string to compare.
  183. * @param [in] str2 Second string to compare.
  184. * @param [in] n Number of characters to compare.
  185. * @return < 0, 0, > 0, see the strcasecmp().
  186. */
  187. int faux_str_casecmpn(const char *str1, const char *str2, size_t n) {
  188. const char *p1 = str1;
  189. const char *p2 = str2;
  190. size_t num = n;
  191. while (*p1 != '\0' && *p2 != '\0' && num != 0) {
  192. int res = faux_str_cmp_chars(faux_ctype_tolower(*p1),
  193. faux_ctype_tolower(*p2));
  194. if (res != 0)
  195. return res;
  196. p1++;
  197. p2++;
  198. num--;
  199. }
  200. if (0 == n) // It means n first characters are equal.
  201. return 0;
  202. return faux_str_cmp_chars(faux_ctype_tolower(*p1),
  203. faux_ctype_tolower(*p2));
  204. }
  205. /** @brief Compare two strings ignoring case.
  206. *
  207. * The difference beetween this function an standard strcasecmp() is
  208. * faux function uses faux ctype functions. It can be important for
  209. * portability.
  210. *
  211. * @param [in] str1 First string to compare.
  212. * @param [in] str2 Second string to compare.
  213. * @return < 0, 0, > 0, see the strcasecmp().
  214. */
  215. int faux_str_casecmp(const char *str1, const char *str2) {
  216. const char *p1 = str1;
  217. const char *p2 = str2;
  218. while (*p1 != '\0' && *p2 != '\0') {
  219. int res = faux_str_cmp_chars(faux_ctype_tolower(*p1),
  220. faux_ctype_tolower(*p2));
  221. if (res != 0)
  222. return res;
  223. p1++;
  224. p2++;
  225. }
  226. return faux_str_cmp_chars(faux_ctype_tolower(*p1),
  227. faux_ctype_tolower(*p2));
  228. }
  229. /** @brief Finds the first occurrence of the substring in the string
  230. *
  231. * Function is a faux version of strcasestr() function.
  232. *
  233. * @param [in] haystack String to find substring in it.
  234. * @param [in] needle Substring to find.
  235. * @return
  236. * Pointer to first occurence of substring in the string.
  237. * NULL on error
  238. */
  239. char *faux_str_casestr(const char *haystack, const char *needle) {
  240. const char *ptr = haystack;
  241. size_t ptr_len = 0;
  242. size_t needle_len = 0;
  243. assert(haystack);
  244. assert(needle);
  245. if (!haystack || !needle)
  246. return NULL;
  247. ptr_len = strlen(haystack);
  248. needle_len = strlen(needle);
  249. while ((*ptr != '\0') && (ptr_len >= needle_len)) {
  250. int res = faux_str_casecmpn(ptr, needle, needle_len);
  251. if (0 == res)
  252. return (char *)ptr;
  253. ptr++;
  254. ptr_len--;
  255. }
  256. return NULL; // Not found
  257. }
  258. /** Prepare string for embedding to C-code (make escaping).
  259. *
  260. * @warning The returned pointer must be freed by faux_str_free().
  261. * @param [in] src String for escaping.
  262. * @return Escaped string or NULL on error.
  263. */
  264. char *faux_str_c_esc(const char *src) {
  265. const char *src_ptr = src;
  266. char *dst = NULL;
  267. char *dst_ptr = NULL;
  268. char *escaped = NULL;
  269. size_t src_len = 0;
  270. size_t dst_len = 0;
  271. assert(src);
  272. if (!src)
  273. return NULL;
  274. src_len = strlen(src);
  275. // Calculate max destination string size.
  276. // The worst case is when each src character will be replaced by
  277. // something like '\xff'. So it's 4 dst chars for 1 src one.
  278. dst_len = (src_len * 4) + 1; // one byte for '\0'
  279. dst = faux_zmalloc(dst_len);
  280. assert(dst);
  281. if (!dst)
  282. return NULL;
  283. dst_ptr = dst;
  284. while (*src_ptr != '\0') {
  285. char *esc = NULL; // escaped replacement
  286. char buf[5]; // longest 'char' (4 bytes) + '\0'
  287. size_t len = 0;
  288. switch (*src_ptr) {
  289. case '\n':
  290. esc = "\\n";
  291. break;
  292. case '\"':
  293. esc = "\\\"";
  294. break;
  295. case '\\':
  296. esc = "\\\\";
  297. break;
  298. case '\'':
  299. esc = "\\\'";
  300. break;
  301. case '\r':
  302. esc = "\\r";
  303. break;
  304. case '\t':
  305. esc = "\\t";
  306. break;
  307. default:
  308. // Check is the symbol control character. Control
  309. // characters has codes from 0x00 to 0x1f.
  310. if (((unsigned char)*src_ptr & 0xe0) == 0) { // control
  311. snprintf(buf, sizeof(buf), "\\x%02x",
  312. (unsigned char)*src_ptr);
  313. buf[4] = '\0'; // for safety
  314. } else {
  315. buf[0] = *src_ptr; // Common character
  316. buf[1] = '\0';
  317. }
  318. esc = buf;
  319. break;
  320. }
  321. len = strlen(esc);
  322. memcpy(dst_ptr, esc, len); // zmalloc() nullify the rest
  323. dst_ptr += len;
  324. src_ptr++;
  325. }
  326. escaped = faux_str_dup(dst); // Free some memory
  327. faux_str_free(dst); // 'dst' size >= 'escaped' size
  328. return escaped;
  329. }
  330. /* TODO: If it nedeed?
  331. const char *faux_str_nextword(const char *string,
  332. size_t *len, size_t *offset, size_t *quoted)
  333. {
  334. const char *word;
  335. *quoted = 0;
  336. // Find the start of a word (not including an opening quote)
  337. while (*string && isspace(*string)) {
  338. string++;
  339. (*offset)++;
  340. }
  341. // Is this the start of a quoted string ?
  342. if (*string == '"') {
  343. *quoted = 1;
  344. string++;
  345. }
  346. word = string;
  347. *len = 0;
  348. // Find the end of the word
  349. while (*string) {
  350. if (*string == '\\') {
  351. string++;
  352. (*len)++;
  353. if (*string) {
  354. (*len)++;
  355. string++;
  356. }
  357. continue;
  358. }
  359. // End of word
  360. if (!*quoted && isspace(*string))
  361. break;
  362. if (*string == '"') {
  363. // End of a quoted string
  364. *quoted = 2;
  365. break;
  366. }
  367. (*len)++;
  368. string++;
  369. }
  370. return word;
  371. }
  372. */
  373. // TODO: Is it needed?
  374. /*
  375. char *lub_string_ndecode(const char *string, unsigned int len)
  376. {
  377. const char *s = string;
  378. char *res, *p;
  379. int esc = 0;
  380. if (!string)
  381. return NULL;
  382. p = res = faux_zmalloc(len + 1);
  383. while (*s && (s < (string +len))) {
  384. if (!esc) {
  385. if ('\\' == *s)
  386. esc = 1;
  387. else
  388. *p = *s;
  389. } else {
  390. // switch (*s) {
  391. // case 'r':
  392. // case 'n':
  393. // *p = '\n';
  394. // break;
  395. // case 't':
  396. // *p = '\t';
  397. // break;
  398. // default:
  399. // *p = *s;
  400. // break;
  401. // }
  402. // *p = *s;
  403. esc = 0;
  404. }
  405. if (!esc)
  406. p++;
  407. s++;
  408. }
  409. *p = '\0';
  410. return res;
  411. }
  412. */
  413. // TODO: Is it needed?
  414. /*
  415. inline char *lub_string_decode(const char *string)
  416. {
  417. return lub_string_ndecode(string, strlen(string));
  418. }
  419. */
  420. // TODO: Is it needed?
  421. /*----------------------------------------------------------- */
  422. /*
  423. * This needs to escape any dangerous characters within the command line
  424. * to prevent gaining access to the underlying system shell.
  425. */
  426. /*
  427. char *lub_string_encode(const char *string, const char *escape_chars)
  428. {
  429. char *result = NULL;
  430. const char *p;
  431. if (!escape_chars)
  432. return lub_string_dup(string);
  433. if (string && !(*string)) // Empty string
  434. return lub_string_dup(string);
  435. for (p = string; p && *p; p++) {
  436. // find any special characters and prefix them with '\'
  437. size_t len = strcspn(p, escape_chars);
  438. lub_string_catn(&result, p, len);
  439. p += len;
  440. if (*p) {
  441. lub_string_catn(&result, "\\", 1);
  442. lub_string_catn(&result, p, 1);
  443. } else {
  444. break;
  445. }
  446. }
  447. return result;
  448. }
  449. */
  450. // TODO: Is it needed?
  451. /*--------------------------------------------------------- */
  452. /*
  453. unsigned int lub_string_equal_part(const char *str1, const char *str2,
  454. bool_t utf8)
  455. {
  456. unsigned int cnt = 0;
  457. if (!str1 || !str2)
  458. return cnt;
  459. while (*str1 && *str2) {
  460. if (*str1 != *str2)
  461. break;
  462. cnt++;
  463. str1++;
  464. str2++;
  465. }
  466. if (!utf8)
  467. return cnt;
  468. // UTF8 features
  469. if (cnt && (UTF8_11 == (*(str1 - 1) & UTF8_MASK)))
  470. cnt--;
  471. return cnt;
  472. }
  473. */
  474. // TODO: Is it needed?
  475. /*--------------------------------------------------------- */
  476. /*
  477. const char *lub_string_suffix(const char *string)
  478. {
  479. const char *p1, *p2;
  480. p1 = p2 = string;
  481. while (*p1) {
  482. if (faux_ctype_isspace(*p1)) {
  483. p2 = p1;
  484. p2++;
  485. }
  486. p1++;
  487. }
  488. return p2;
  489. }
  490. */
  491. // TODO: Is it needed?
  492. /*--------------------------------------------------------- */
  493. /*
  494. unsigned int lub_string_wordcount(const char *line)
  495. {
  496. const char *word;
  497. unsigned int result = 0;
  498. size_t len = 0, offset = 0;
  499. size_t quoted;
  500. for (word = lub_string_nextword(line, &len, &offset, &quoted);
  501. *word || quoted;
  502. word = lub_string_nextword(word + len, &len, &offset, &quoted)) {
  503. // account for the terminating quotation mark
  504. len += quoted ? quoted - 1 : 0;
  505. result++;
  506. }
  507. return result;
  508. }
  509. */