Avoid unnecessary regeneration of dependencies.
[paraslash.git] / string.c
1 /*
2 * Copyright (C) 2004-2009 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file string.c Memory allocation and string handling functions. */
8
9 #include <sys/time.h> /* gettimeofday */
10 #include <pwd.h>
11 #include <sys/utsname.h> /* uname() */
12 #include <string.h>
13 #include <regex.h>
14
15 #include "para.h"
16 #include "string.h"
17 #include "error.h"
18
19 /**
20 * Paraslash's version of realloc().
21 *
22 * \param p Pointer to the memory block, may be \p NULL.
23 * \param size The desired new size.
24 *
25 * A wrapper for realloc(3). It calls \p exit(\p EXIT_FAILURE) on errors,
26 * i.e. there is no need to check the return value in the caller.
27 *
28 * \return A pointer to the newly allocated memory, which is suitably aligned
29 * for any kind of variable and may be different from \a p.
30 *
31 * \sa realloc(3).
32 */
33 __must_check __malloc void *para_realloc(void *p, size_t size)
34 {
35 /*
36 * No need to check for NULL pointers: If p is NULL, the call
37 * to realloc is equivalent to malloc(size)
38 */
39 assert(size);
40 if (!(p = realloc(p, size))) {
41 PARA_EMERG_LOG("realloc failed (size = %zu), aborting\n",
42 size);
43 exit(EXIT_FAILURE);
44 }
45 return p;
46 }
47
48 /**
49 * Paraslash's version of malloc().
50 *
51 * \param size The desired new size.
52 *
53 * A wrapper for malloc(3) which exits on errors.
54 *
55 * \return A pointer to the allocated memory, which is suitably aligned for any
56 * kind of variable.
57 *
58 * \sa malloc(3).
59 */
60 __must_check __malloc void *para_malloc(size_t size)
61 {
62 void *p;
63
64 assert(size);
65 p = malloc(size);
66 if (!p) {
67 PARA_EMERG_LOG("malloc failed (size = %zu), aborting\n",
68 size);
69 exit(EXIT_FAILURE);
70 }
71 return p;
72 }
73
74 /**
75 * Paraslash's version of calloc().
76 *
77 * \param size The desired new size.
78 *
79 * A wrapper for calloc(3) which exits on errors.
80 *
81 * \return A pointer to the allocated and zeroed-out memory, which is suitably
82 * aligned for any kind of variable.
83 *
84 * \sa calloc(3)
85 */
86 __must_check __malloc void *para_calloc(size_t size)
87 {
88 void *ret = para_malloc(size);
89
90 memset(ret, 0, size);
91 return ret;
92 }
93
94 /**
95 * Paraslash's version of strdup().
96 *
97 * \param s The string to be duplicated.
98 *
99 * A wrapper for strdup(3). It calls \p exit(EXIT_FAILURE) on errors, i.e.
100 * there is no need to check the return value in the caller.
101 *
102 * \return A pointer to the duplicated string. If \a s was the \p NULL pointer,
103 * an pointer to an empty string is returned.
104 *
105 * \sa strdup(3)
106 */
107 __must_check __malloc char *para_strdup(const char *s)
108 {
109 char *ret;
110
111 if ((ret = strdup(s? s: "")))
112 return ret;
113 PARA_EMERG_LOG("strdup failed, aborting\n");
114 exit(EXIT_FAILURE);
115 }
116
117 /**
118 * Allocate a sufficiently large string and print into it.
119 *
120 * \param fmt A usual format string.
121 *
122 * Produce output according to \p fmt. No artificial bound on the length of the
123 * resulting string is imposed.
124 *
125 * \return This function either returns a pointer to a string that must be
126 * freed by the caller or aborts without returning.
127 *
128 * \sa printf(3).
129 */
130 __must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
131 {
132 char *msg;
133
134 PARA_VSPRINTF(fmt, msg);
135 return msg;
136 }
137
138 void freep(void *arg)
139 {
140 void **ptr = (void **)arg;
141 free(*ptr);
142 *ptr = NULL;
143 }
144
145 /**
146 * Paraslash's version of strcat().
147 *
148 * \param a String to be appended to.
149 * \param b String to append.
150 *
151 * Append \p b to \p a.
152 *
153 * \return If \a a is \p NULL, return a pointer to a copy of \a b, i.e.
154 * para_strcat(NULL, b) is equivalent to para_strdup(b). If \a b is \p NULL,
155 * return \a a without making a copy of \a a. Otherwise, construct the
156 * concatenation \a c, free \a a (but not \a b) and return \a c.
157 *
158 * \sa strcat(3)
159 */
160 __must_check __malloc char *para_strcat(char *a, const char *b)
161 {
162 char *tmp;
163
164 if (!a)
165 return para_strdup(b);
166 if (!b)
167 return a;
168 tmp = make_message("%s%s", a, b);
169 free(a);
170 return tmp;
171 }
172
173 /**
174 * Paraslash's version of dirname().
175 *
176 * \param name Pointer to the full path.
177 *
178 * Compute the directory component of \p name.
179 *
180 * \return If \a name is \p NULL or the empty string, return \p NULL.
181 * Otherwise, Make a copy of \a name and return its directory component. Caller
182 * is responsible to free the result.
183 */
184 __must_check __malloc char *para_dirname(const char *name)
185 {
186 char *p, *ret;
187
188 if (!name || !*name)
189 return NULL;
190 ret = para_strdup(name);
191 p = strrchr(ret, '/');
192 if (!p)
193 *ret = '\0';
194 else
195 *p = '\0';
196 return ret;
197 }
198
199 /**
200 * Paraslash's version of basename().
201 *
202 * \param name Pointer to the full path.
203 *
204 * Compute the filename component of \a name.
205 *
206 * \return \p NULL if (a) \a name is the empty string or \p NULL, or (b) name
207 * ends with a slash. Otherwise, a pointer within \a name is returned. Caller
208 * must not free the result.
209 */
210 __must_check char *para_basename(const char *name)
211 {
212 char *ret;
213
214 if (!name || !*name)
215 return NULL;
216 ret = strrchr(name, '/');
217 if (!ret)
218 return (char *)name;
219 ret++;
220 return ret;
221 }
222
223 /**
224 * Cut trailing newline.
225 *
226 * \param buf The string to be chopped.
227 *
228 * Replace the last character in \p buf by zero if it is equal to
229 * the newline character.
230 */
231 void chop(char *buf)
232 {
233 int n = strlen(buf);
234
235 if (!n)
236 return;
237 if (buf[n - 1] == '\n')
238 buf[n - 1] = '\0';
239 }
240
241 /**
242 * Get the logname of the current user.
243 *
244 * \return A dynamically allocated string that must be freed by the caller. On
245 * errors, the string "unknown_user" is returned, i.e. this function never
246 * returns \p NULL.
247 *
248 * \sa getpwuid(3).
249 */
250 __must_check __malloc char *para_logname(void)
251 {
252 struct passwd *pw = getpwuid(getuid());
253 return para_strdup(pw? pw->pw_name : "unknown_user");
254 }
255
256 /**
257 * Get the home directory of the current user.
258 *
259 * \return A dynamically allocated string that must be freed by the caller. If
260 * the home directory could not be found, this function returns "/tmp".
261 */
262 __must_check __malloc char *para_homedir(void)
263 {
264 struct passwd *pw = getpwuid(getuid());
265 return para_strdup(pw? pw->pw_dir : "/tmp");
266 }
267
268 /**
269 * Get the own hostname.
270 *
271 * \return A dynamically allocated string containing the hostname.
272 *
273 * \sa uname(2).
274 */
275 __malloc char *para_hostname(void)
276 {
277 struct utsname u;
278
279 uname(&u);
280 return para_strdup(u.nodename);
281 }
282
283 /**
284 * Used to distinguish between read-only and read-write mode.
285 *
286 * \sa for_each_line(), for_each_line_ro().
287 */
288 enum for_each_line_modes{
289 /** Activate read-only mode. */
290 LINE_MODE_RO,
291 /** Activate read-write mode. */
292 LINE_MODE_RW
293 };
294
295 static int for_each_complete_line(enum for_each_line_modes mode, char *buf,
296 size_t size, line_handler_t *line_handler, void *private_data)
297 {
298 char *start = buf, *end;
299 int ret, i, num_lines = 0;
300
301 // PARA_NOTICE_LOG("buf: %s\n", buf);
302 while (start < buf + size) {
303 char *next_null;
304 char *next_cr;
305
306 next_cr = memchr(start, '\n', buf + size - start);
307 next_null = memchr(start, '\0', buf + size - start);
308 if (!next_cr && !next_null)
309 break;
310 if (next_cr && next_null) {
311 end = next_cr < next_null? next_cr : next_null;
312 } else if (next_null) {
313 end = next_null;
314 } else
315 end = next_cr;
316 num_lines++;
317 if (!line_handler) {
318 start = ++end;
319 continue;
320 }
321 if (mode == LINE_MODE_RO) {
322 size_t s = end - start;
323 char *b = para_malloc(s + 1);
324 memcpy(b, start, s);
325 b[s] = '\0';
326 // PARA_NOTICE_LOG("b: %s, start: %s\n", b, start);
327 ret = line_handler(b, private_data);
328 free(b);
329 } else {
330 *end = '\0';
331 ret = line_handler(start, private_data);
332 }
333 if (ret < 0)
334 return ret;
335 start = ++end;
336 }
337 if (!line_handler || mode == LINE_MODE_RO)
338 return num_lines;
339 i = buf + size - start;
340 if (i && i != size)
341 memmove(buf, start, i);
342 return i;
343 }
344
345 /**
346 * Call a custom function for each complete line.
347 *
348 * \param buf The buffer containing data separated by newlines.
349 * \param size The number of bytes in \a buf.
350 * \param line_handler The custom function.
351 * \param private_data Pointer passed to \a line_handler.
352 *
353 * If \p line_handler is \p NULL, the function returns the number of complete
354 * lines in \p buf. Otherwise, \p line_handler is called for each complete
355 * line in \p buf. The first argument to \p line_handler is the current line,
356 * and \p private_data is passed as the second argument. The function returns
357 * if \p line_handler returns a negative value or no more lines are in the
358 * buffer. The rest of the buffer (last chunk containing an incomplete line)
359 * is moved to the beginning of the buffer.
360 *
361 * \return If \p line_handler is not \p NULL, this function returns the number
362 * of bytes not handled to \p line_handler on success, or the negative return
363 * value of the \p line_handler on errors.
364 *
365 * \sa for_each_line_ro().
366 */
367 int for_each_line(char *buf, size_t size, line_handler_t *line_handler,
368 void *private_data)
369 {
370 return for_each_complete_line(LINE_MODE_RW, buf, size, line_handler,
371 private_data);
372 }
373
374 /**
375 * Call a custom function for each complete line.
376 *
377 * \param buf Same meaning as in \p for_each_line().
378 * \param size Same meaning as in \p for_each_line().
379 * \param line_handler Same meaning as in \p for_each_line().
380 * \param private_data Same meaning as in \p for_each_line().
381 *
382 * This function behaves like \p for_each_line(), but \a buf is left unchanged.
383 *
384 * \return On success, the function returns the number of complete lines in \p
385 * buf, otherwise the (negative) return value of \p line_handler is returned.
386 *
387 * \sa for_each_line().
388 */
389 int for_each_line_ro(char *buf, size_t size, line_handler_t *line_handler,
390 void *private_data)
391 {
392 return for_each_complete_line(LINE_MODE_RO, buf, size, line_handler,
393 private_data);
394 }
395
396 #define hex(a) (hexchar[(a) & 15])
397 static void write_size_header(char *buf, int n)
398 {
399 static char hexchar[] = "0123456789abcdef";
400
401 buf[0] = hex(n >> 12);
402 buf[1] = hex(n >> 8);
403 buf[2] = hex(n >> 4);
404 buf[3] = hex(n);
405 buf[4] = ' ';
406 }
407
408 int read_size_header(const char *buf)
409 {
410 int i, len = 0;
411
412 for (i = 0; i < 4; i++) {
413 unsigned char c = buf[i];
414 len <<= 4;
415 if (c >= '0' && c <= '9') {
416 len += c - '0';
417 continue;
418 }
419 if (c >= 'a' && c <= 'f') {
420 len += c - 'a' + 10;
421 continue;
422 }
423 return -E_SIZE_PREFIX;
424 }
425 if (buf[4] != ' ')
426 return -E_SIZE_PREFIX;
427 return len;
428 }
429
430 /**
431 * Safely print into a buffer at a given offset.
432 *
433 * \param b Determines the buffer, its size, and the offset.
434 * \param fmt The format string.
435 *
436 * This function prints into the buffer given by \a b at the offset which is
437 * also given by \a b. If there is not enough space to hold the result, the
438 * buffer size is doubled until the underlying call to vsnprintf() succeeds
439 * or the size of the buffer exceeds the maximal size specified in \a b.
440 *
441 * In the latter case the unmodified \a buf and \a offset values as well as the
442 * private_data pointer of \a b are passed to the \a max_size_handler of \a b.
443 * If this function succeeds, i.e. returns a non-negative value, the offset of
444 * \a b is reset to zero and the given data is written to the beginning of the
445 * buffer. If \a max_size_handler() returns a negative value, this value is
446 * returned by \a para_printf().
447 *
448 * Upon return, the offset of \a b is adjusted accordingly so that subsequent
449 * calls to this function append data to what is already contained in the
450 * buffer.
451 *
452 * It's OK to call this function with \p b->buf being \p NULL. In this case, an
453 * initial buffer is allocated.
454 *
455 * \return The number of bytes printed into the buffer (not including the
456 * terminating \p NULL byte) on success, negative on errors. If there is no
457 * size-bound on \a b, i.e. if \p b->max_size is zero, this function never
458 * fails.
459 *
460 * \sa make_message(), vsnprintf(3).
461 */
462 __printf_2_3 int para_printf(struct para_buffer *b, const char *fmt, ...)
463 {
464 int ret, sz_off = (b->flags & PBF_SIZE_PREFIX)? 5 : 0;
465
466 if (!b->buf) {
467 b->buf = para_malloc(128);
468 b->size = 128;
469 b->offset = 0;
470 }
471 while (1) {
472 char *p = b->buf + b->offset;
473 size_t size = b->size - b->offset;
474 va_list ap;
475
476 if (size > sz_off) {
477 va_start(ap, fmt);
478 ret = vsnprintf(p + sz_off, size - sz_off, fmt, ap);
479 va_end(ap);
480 if (ret > -1 && ret < size - sz_off) { /* success */
481 b->offset += ret + sz_off;
482 if (sz_off)
483 write_size_header(p, ret);
484 return ret + sz_off;
485 }
486 }
487 /* check if we may grow the buffer */
488 if (!b->max_size || 2 * b->size < b->max_size) { /* yes */
489 /* try again with more space */
490 b->size *= 2;
491 b->buf = para_realloc(b->buf, b->size);
492 continue;
493 }
494 /* can't grow buffer */
495 if (!b->offset || !b->max_size_handler) /* message too large */
496 return -ERRNO_TO_PARA_ERROR(ENOSPC);
497 ret = b->max_size_handler(b->buf, b->offset, b->private_data);
498 if (ret < 0)
499 return ret;
500 b->offset = 0;
501 }
502 }
503
504 /** \cond LLONG_MAX and LLONG_LIN might not be defined. */
505 #ifndef LLONG_MAX
506 #define LLONG_MAX (1 << (sizeof(long) - 1))
507 #endif
508 #ifndef LLONG_MIN
509 #define LLONG_MIN (-LLONG_MAX - 1LL)
510 #endif
511 /** \endcond */
512
513 /**
514 * Convert a string to a 64-bit signed integer value.
515 *
516 * \param str The string to be converted.
517 * \param value Result pointer.
518 *
519 * \return Standard.
520 *
521 * \sa para_atoi32(), strtol(3), atoi(3).
522 */
523 int para_atoi64(const char *str, int64_t *value)
524 {
525 char *endptr;
526 long long tmp;
527
528 errno = 0; /* To distinguish success/failure after call */
529 tmp = strtoll(str, &endptr, 10);
530 if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
531 return -E_ATOI_OVERFLOW;
532 if (errno != 0 && tmp == 0) /* other error */
533 return -E_STRTOLL;
534 if (endptr == str)
535 return -E_ATOI_NO_DIGITS;
536 if (*endptr != '\0') /* Further characters after number */
537 return -E_ATOI_JUNK_AT_END;
538 *value = tmp;
539 return 1;
540 }
541
542 /**
543 * Convert a string to a 32-bit signed integer value.
544 *
545 * \param str The string to be converted.
546 * \param value Result pointer.
547 *
548 * \return Standard.
549 *
550 * \sa para_atoi64().
551 */
552 int para_atoi32(const char *str, int32_t *value)
553 {
554 int64_t tmp;
555 int ret;
556 const int32_t max = 2147483647;
557
558 ret = para_atoi64(str, &tmp);
559 if (ret < 0)
560 return ret;
561 if (tmp > max || tmp < -max - 1)
562 return -E_ATOI_OVERFLOW;
563 *value = tmp;
564 return 1;
565 }
566
567 static inline int loglevel_equal(const char *arg, const char * const ll)
568 {
569 return !strncasecmp(arg, ll, strlen(ll));
570 }
571
572 /**
573 * Compute the loglevel number from its name.
574 *
575 * \param txt The name of the loglevel (debug, info, ...).
576 *
577 * \return The numeric representation of the loglevel name.
578 */
579 int get_loglevel_by_name(const char *txt)
580 {
581 if (loglevel_equal(txt, "debug"))
582 return LL_DEBUG;
583 if (loglevel_equal(txt, "info"))
584 return LL_INFO;
585 if (loglevel_equal(txt, "notice"))
586 return LL_NOTICE;
587 if (loglevel_equal(txt, "warning"))
588 return LL_WARNING;
589 if (loglevel_equal(txt, "error"))
590 return LL_ERROR;
591 if (loglevel_equal(txt, "crit"))
592 return LL_CRIT;
593 if (loglevel_equal(txt, "emerg"))
594 return LL_EMERG;
595 return -1;
596 }
597
598 static int get_next_word(const char *buf, const char *delim, char **word)
599 {
600 enum line_state_flags {LSF_HAVE_WORD = 1, LSF_BACKSLASH = 2,
601 LSF_SINGLE_QUOTE = 4, LSF_DOUBLE_QUOTE = 8};
602 const char *in;
603 char *out;
604 int ret, state = 0;
605
606 out = para_malloc(strlen(buf) + 1);
607 *out = '\0';
608 *word = out;
609 for (in = buf; *in; in++) {
610 const char *p;
611
612 switch (*in) {
613 case '\\':
614 if (state & LSF_BACKSLASH) /* \\ */
615 goto copy_char;
616 state |= LSF_BACKSLASH;
617 state |= LSF_HAVE_WORD;
618 continue;
619 case 'n':
620 case 't':
621 if (state & LSF_BACKSLASH) { /* \n or \t */
622 *out++ = (*in == 'n')? '\n' : '\t';
623 state &= ~LSF_BACKSLASH;
624 continue;
625 }
626 goto copy_char;
627 case '"':
628 if (state & LSF_BACKSLASH) /* \" */
629 goto copy_char;
630 if (state & LSF_SINGLE_QUOTE) /* '" */
631 goto copy_char;
632 if (state & LSF_DOUBLE_QUOTE) {
633 state &= ~LSF_DOUBLE_QUOTE;
634 continue;
635 }
636 state |= LSF_HAVE_WORD;
637 state |= LSF_DOUBLE_QUOTE;
638 continue;
639 case '\'':
640 if (state & LSF_BACKSLASH) /* \' */
641 goto copy_char;
642 if (state & LSF_DOUBLE_QUOTE) /* "' */
643 goto copy_char;
644 if (state & LSF_SINGLE_QUOTE) {
645 state &= ~LSF_SINGLE_QUOTE;
646 continue;
647 }
648 state |= LSF_HAVE_WORD;
649 state |= LSF_SINGLE_QUOTE;
650 continue;
651 }
652 for (p = delim; *p; p++) {
653 if (*in != *p)
654 continue;
655 if (state & LSF_BACKSLASH)
656 goto copy_char;
657 if (state & LSF_SINGLE_QUOTE)
658 goto copy_char;
659 if (state & LSF_DOUBLE_QUOTE)
660 goto copy_char;
661 if (state & LSF_HAVE_WORD)
662 goto success;
663 break;
664 }
665 if (*p) /* ignore delimiter at the beginning */
666 continue;
667 copy_char:
668 state |= LSF_HAVE_WORD;
669 *out++ = *in;
670 state &= ~LSF_BACKSLASH;
671 }
672 ret = 0;
673 if (!(state & LSF_HAVE_WORD))
674 goto out;
675 ret = -ERRNO_TO_PARA_ERROR(EINVAL);
676 if (state & LSF_BACKSLASH) {
677 PARA_ERROR_LOG("trailing backslash\n");
678 goto out;
679 }
680 if ((state & LSF_SINGLE_QUOTE) || (state & LSF_DOUBLE_QUOTE)) {
681 PARA_ERROR_LOG("unmatched quote character\n");
682 goto out;
683 }
684 success:
685 *out = '\0';
686 return in - buf;
687 out:
688 free(*word);
689 *word = NULL;
690 return ret;
691 }
692
693 /**
694 * Free an array of words created by create_argv().
695 *
696 * \param argv A pointer previously obtained by \ref create_argv().
697 */
698 void free_argv(char **argv)
699 {
700 int i;
701
702 for (i = 0; argv[i]; i++)
703 free(argv[i]);
704 free(argv);
705 }
706
707 /**
708 * Split a buffer into words.
709 *
710 * This parser honors single and double quotes, backslash-escaped characters
711 * and special characters like \p \\n. The result contains pointers to copies
712 * of the words contained in \a buf and has to be freed by using \ref
713 * free_argv().
714 *
715 * \param buf The buffer to be split.
716 * \param delim Each character in this string is treated as a separator.
717 * \param result The array of words is returned here.
718 *
719 * \return Number of words in \a buf, negative on errors.
720 */
721 int create_argv(const char *buf, const char *delim, char ***result)
722 {
723 char *word, **argv = para_malloc(2 * sizeof(char *));
724 const char *p;
725 int ret, num_words;
726
727 for (p = buf, num_words = 0; ; p += ret, num_words++) {
728 ret = get_next_word(p, delim, &word);
729 if (ret < 0)
730 goto err;
731 if (!ret)
732 break;
733 argv = para_realloc(argv, (num_words + 2) * sizeof(char*));
734 argv[num_words] = word;
735 }
736 argv[num_words] = NULL;
737 *result = argv;
738 return num_words;
739 err:
740 while (num_words > 0)
741 free(argv[--num_words]);
742 free(argv);
743 return ret;
744 }
745
746 int para_regcomp(regex_t *preg, const char *regex, int cflags)
747 {
748 char *buf;
749 size_t size;
750 int ret = regcomp(preg, regex, cflags);
751
752 if (ret == 0)
753 return 1;
754 size = regerror(ret, preg, NULL, 0);
755 buf = para_malloc(size);
756 regerror(ret, preg, buf, size);
757 PARA_ERROR_LOG("%s\n", buf);
758 free(buf);
759 return -E_REGEX;
760 }