2 * Copyright (C) 2004-2008 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file string.c Memory allocation and string handling functions. */
12 #include <sys/time.h> /* gettimeofday */
14 #include <sys/utsname.h> /* uname() */
20 * Paraslash's version of realloc().
22 * \param p Pointer to the memory block, may be \p NULL.
23 * \param size The desired new size.
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.
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.
33 __must_check __malloc void *para_realloc(void *p, size_t size)
36 * No need to check for NULL pointers: If p is NULL, the call
37 * to realloc is equivalent to malloc(size)
40 if (!(p = realloc(p, size))) {
41 PARA_EMERG_LOG("realloc failed (size = %zu), aborting\n",
49 * Paraslash's version of malloc().
51 * \param size The desired new size.
53 * A wrapper for malloc(3) which exits on errors.
55 * \return A pointer to the allocated memory, which is suitably aligned for any
60 __must_check __malloc void *para_malloc(size_t size)
63 void *p = malloc(size);
66 PARA_EMERG_LOG("malloc failed (size = %zu), aborting\n",
74 * Paraslash's version of calloc().
76 * \param size The desired new size.
78 * A wrapper for calloc(3) which exits on errors.
80 * \return A pointer to the allocated and zeroed-out memory, which is suitably
81 * aligned for any kind of variable.
85 __must_check __malloc void *para_calloc(size_t size)
87 void *ret = para_malloc(size);
94 * Paraslash's version of strdup().
96 * \param s The string to be duplicated.
98 * A wrapper for strdup(3). It calls \p exit(EXIT_FAILURE) on errors, i.e.
99 * there is no need to check the return value in the caller.
101 * \return A pointer to the duplicated string. If \p s was the NULL pointer,
102 * an pointer to an empty string is returned.
106 __must_check __malloc char *para_strdup(const char *s)
110 if ((ret = strdup(s? s: "")))
112 PARA_EMERG_LOG("strdup failed, aborting\n");
117 * Allocate a sufficiently large string and print into it.
119 * \param fmt A usual format string.
121 * Produce output according to \p fmt. No artificial bound on the length of the
122 * resulting string is imposed.
124 * \return This function either returns a pointer to a string that must be
125 * freed by the caller or aborts without returning.
129 __must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
133 PARA_VSPRINTF(fmt, msg);
138 * Paraslash's version of strcat().
140 * \param a String to be appended to.
141 * \param b String to append.
143 * Append \p b to \p a.
145 * \return If \a a is \p NULL, return a pointer to a copy of \a b, i.e.
146 * para_strcat(NULL, b) is equivalent to para_strdup(b). If \a b is \p NULL,
147 * return \a a without making a copy of \a a. Otherwise, construct the
148 * concatenation \a c, free \a a (but not \a b) and return \a c.
152 __must_check __malloc char *para_strcat(char *a, const char *b)
157 return para_strdup(b);
160 tmp = make_message("%s%s", a, b);
166 * Paraslash's version of dirname().
168 * \param name Pointer to the full path.
170 * Compute the directory component of \p name.
172 * \return If \a name is \p NULL or the empty string, return \p NULL.
173 * Otherwise, Make a copy of \a name and return its directory component. Caller
174 * is responsible to free the result.
176 __must_check __malloc char *para_dirname(const char *name)
182 ret = para_strdup(name);
183 p = strrchr(ret, '/');
192 * Paraslash's version of basename().
194 * \param name Pointer to the full path.
196 * Compute the filename component of \a name.
198 * \return \p NULL if (a) \a name is the empty string or \p NULL, or (b) name
199 * ends with a slash. Otherwise, a pointer within \a name is returned. Caller
200 * must not free the result.
202 __must_check const char *para_basename(const char *name)
208 ret = strrchr(name, '/');
216 * Cut trailing newline.
218 * \param buf The string to be chopped.
220 * Replace the last character in \p buf by zero if it is euqal to
221 * the newline character.
228 if (buf[n - 1] == '\n')
233 * Get a random filename.
235 * This is by no means a secure way to create temporary files in a hostile
236 * direcory like \p /tmp. However, it is OK to use for temp files, fifos,
237 * sockets that are created in ~/.paraslash. Result must be freed by the
240 * \return A pointer to a random filename.
242 __must_check __malloc char *para_tmpname(void)
247 gettimeofday(&now, NULL);
250 return make_message("%08i", rand());
254 * Get the logname of the current user.
256 * \return A dynammically allocated string that must be freed by the caller. On
257 * errors, the string "unknown user" is returned, i.e. this function never
262 __must_check __malloc char *para_logname(void)
264 struct passwd *pw = getpwuid(getuid());
265 return para_strdup(pw? pw->pw_name : "unknown_user");
269 * Get the home directory of the current user.
271 * \return A dynammically allocated string that must be freed by the caller. If
272 * the home directory could not be found, this function returns "/tmp".
274 __must_check __malloc char *para_homedir(void)
276 struct passwd *pw = getpwuid(getuid());
277 return para_strdup(pw? pw->pw_dir : "/tmp");
281 * Split string and return pointers to its parts.
283 * \param args The string to be split.
284 * \param argv_ptr Pointer to the list of substrings.
285 * \param delim Delimiter.
287 * This function modifies \a args by replacing each occurance of \a delim by
288 * zero. A \p NULL-terminated array of pointers to char* is allocated dynamically
289 * and these pointers are initialized to point to the broken-up substrings
290 * within \a args. A pointer to this array is returned via \a argv_ptr.
292 * \return The number of substrings found in \a args.
294 __must_check unsigned split_args(char *args, char *** const argv_ptr, const char *delim)
300 p = args + strspn(args, delim);
302 i = strcspn(p, delim);
307 p += strspn(p, delim);
309 *argv_ptr = para_malloc((n + 1) * sizeof(char *));
312 p = args + strspn(args, delim);
315 j = strcspn(p, delim);
318 p += strcspn(p, delim);
322 p += strspn(p, delim);
331 * Ensure that file descriptors 0, 1, and 2 are valid.
333 * Common approach that opens /dev/null until it gets a file descriptor greater
336 * \sa okir's Black Hats Manual.
338 void valid_fd_012(void)
341 int fd = open("/dev/null", O_RDWR);
352 * Get the own hostname.
354 * \return A dynammically allocated string containing the hostname.
358 __malloc char *para_hostname(void)
363 return para_strdup(u.nodename);
367 * Used to distinguish between read-only and read-write mode.
369 * \sa for_each_line(), for_each_line_ro().
371 enum for_each_line_modes{
372 /** Activate read-only mode. */
374 /** Activate read-write mode. */
378 static int for_each_complete_line(enum for_each_line_modes mode, char *buf,
379 size_t size, line_handler_t *line_handler, void *private_data)
381 char *start = buf, *end;
382 int ret, i, num_lines = 0;
384 // PARA_NOTICE_LOG("buf: %s\n", buf);
385 while (start < buf + size) {
389 next_cr = memchr(start, '\n', buf + size - start);
390 next_null = memchr(start, '\0', buf + size - start);
391 if (!next_cr && !next_null)
393 if (next_cr && next_null) {
394 end = next_cr < next_null? next_cr : next_null;
395 } else if (next_null) {
404 if (mode == LINE_MODE_RO) {
405 size_t s = end - start;
406 char *b = para_malloc(s + 1);
409 // PARA_NOTICE_LOG("b: %s, start: %s\n", b, start);
410 ret = line_handler(b, private_data);
414 ret = line_handler(start, private_data);
420 if (!line_handler || mode == LINE_MODE_RO)
422 i = buf + size - start;
424 memmove(buf, start, i);
429 * Call a custom function for each complete line.
431 * \param buf The buffer containing data seperated by newlines.
432 * \param size The number of bytes in \a buf.
433 * \param line_handler The custom function.
434 * \param private_data Pointer passed to \a line_handler.
436 * If \p line_handler is \p NULL, the function returns the number of complete
437 * lines in \p buf. Otherwise, \p line_handler is called for each complete
438 * line in \p buf. The first argument to \p line_handler is the current line,
439 * and \p private_data is passed as the second argument. The function returns
440 * if \p line_handler returns a negative value or no more lines are in the
441 * buffer. The rest of the buffer (last chunk containing an incomplete line)
442 * is moved to the beginning of the buffer.
444 * \return If \p line_handler is not \p NULL, this function returns the number
445 * of bytes not handled to \p line_handler on success, or the negative return
446 * value of the \p line_handler on errors.
448 * \sa for_each_line_ro().
450 int for_each_line(char *buf, size_t size, line_handler_t *line_handler,
453 return for_each_complete_line(LINE_MODE_RW, buf, size, line_handler,
458 * Call a custom function for each complete line.
460 * \param buf Same meaning as in \p for_each_line().
461 * \param size Same meaning as in \p for_each_line().
462 * \param line_handler Same meaning as in \p for_each_line().
463 * \param private_data Same meaning as in \p for_each_line().
465 * This function behaves like \p for_each_line(), but \a buf is left unchanged.
467 * \return On success, the function returns the number of complete lines in \p
468 * buf, otherwise the (negative) return value of \p line_handler is returned.
470 * \sa for_each_line().
472 int for_each_line_ro(char *buf, size_t size, line_handler_t *line_handler,
475 return for_each_complete_line(LINE_MODE_RO, buf, size, line_handler,
480 * Safely print into a buffer at a given offset
482 * \param b Determines the buffer, its size, and the offset.
483 * \param fmt The format string.
485 * This function prints into the buffer given by \a b at the offset which is
486 * also given by \a b. If there is not enough space to hold the result, the
487 * buffer size is doubled until the underlying call to vsnprintf() succeeds
488 * or the size of the buffer exceeds the maximal size specified in \a pb.
490 * In the latter case the unmodified \a buf and \a offset values as well as the
491 * private_data pointer of \a b are passed to the \a max_size_handler of \a b.
492 * If this function succeeds, i.e. returns a non-negative value, the offset of
493 * \a b is reset to zero and the given data is written to the beginning of the
496 * Upon return, the offset of \a b is adjusted accordingly so that subsequent
497 * calls to this function append data to what is already contained in the
500 * It's OK to call this function with \p b->buf being \p NULL. In this case, an
501 * initial buffer is allocated.
503 * \return The number of bytes printed into the buffer (not including the
504 * therminating \p NULL byte).
506 * \sa make_message(), vsnprintf(3).
508 __printf_2_3 int para_printf(struct para_buffer *b, const char *fmt, ...)
513 b->buf = para_malloc(128);
518 char *p = b->buf + b->offset;
519 size_t size = b->size - b->offset;
523 ret = vsnprintf(p, size, fmt, ap);
525 if (ret > -1 && ret < size) { /* success */
530 /* check if we may grow the buffer */
531 if (!b->max_size || 2 * b->size < b->max_size) { /* yes */
532 /* try again with more space */
534 b->buf = para_realloc(b->buf, b->size);
537 /* can't grow buffer */
538 if (!b->offset || !b->max_size_handler) /* message too large */
539 return -ERRNO_TO_PARA_ERROR(ENOSPC);
540 ret = b->max_size_handler(b->buf, b->offset, b->private_data);
547 /** \cond LLONG_MAX and LLONG_LIN might not be defined. */
549 #define LLONG_MAX (1 << (sizeof(long) - 1))
552 #define LLONG_MIN (-LLONG_MAX - 1LL)
557 * Convert a string to a 64-bit signed integer value.
559 * \param str The string to be converted.
560 * \param value Result pointer.
564 * \sa para_atoi32(), strtol(3), atoi(3).
566 int para_atoi64(const char *str, int64_t *value)
571 errno = 0; /* To distinguish success/failure after call */
572 tmp = strtoll(str, &endptr, 10);
573 if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
574 return -E_ATOI_OVERFLOW;
575 if (errno != 0 && tmp == 0) /* other error */
578 return -E_ATOI_NO_DIGITS;
579 if (*endptr != '\0') /* Further characters after number */
580 return -E_ATOI_JUNK_AT_END;
586 * Convert a string to a 32-bit signed integer value.
588 * \param str The string to be converted.
589 * \param value Result pointer.
595 int para_atoi32(const char *str, int32_t *value)
599 const int32_t max = 2147483647;
601 ret = para_atoi64(str, &tmp);
604 if (tmp > max || tmp < -max - 1)
605 return -E_ATOI_OVERFLOW;