Get rid of E_MKSTEMP and E_FCHMOD.
[paraslash.git] / string.c
1 /*
2 * Copyright (C) 2004-2008 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 "para.h"
10 #include "string.h"
11
12 #include <sys/time.h> /* gettimeofday */
13 #include <pwd.h>
14 #include <sys/utsname.h> /* uname() */
15 #include <string.h>
16
17 #include "error.h"
18
19 /**
20 * paraslash's version of realloc()
21 *
22 * \param p pointer to the memory block, may be NULL
23 * \param size 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 \p 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 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 assert(size);
63 void *p = malloc(size);
64
65 if (!p) {
66 PARA_EMERG_LOG("malloc failed (size = %zu), aborting\n",
67 size);
68 exit(EXIT_FAILURE);
69 }
70 return p;
71 }
72
73 /**
74 * paraslash's version of calloc()
75 *
76 * \param size desired new size
77 *
78 * A wrapper for calloc(3) which exits on errors.
79 *
80 * \return A pointer to the allocated and zeroed-out memory, which is suitably
81 * aligned for any kind of variable.
82 *
83 * \sa calloc(3)
84 */
85 __must_check __malloc void *para_calloc(size_t size)
86 {
87 void *ret = para_malloc(size);
88
89 memset(ret, 0, size);
90 return ret;
91 }
92
93 /**
94 * paraslash's version of strdup()
95 *
96 * \param s string to be duplicated
97 *
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.
100 *
101 * \return A pointer to the duplicated string. If \p s was the NULL pointer,
102 * an pointer to an empty string is returned.
103 *
104 * \sa strdup(3)
105 */
106 __must_check __malloc char *para_strdup(const char *s)
107 {
108 char *ret;
109
110 if ((ret = strdup(s? s: "")))
111 return ret;
112 PARA_EMERG_LOG("%s", "strdup failed, aborting\n");
113 exit(EXIT_FAILURE);
114 }
115
116 /**
117 * allocate a sufficiently large string and print into it
118 *
119 * \param fmt usual format string
120 *
121 * Produce output according to \p fmt. No artificial bound on the length of the
122 * resulting string is imposed.
123 *
124 * \return This function either returns a pointer to a string that must be
125 * freed by the caller or aborts without returning.
126 *
127 * \sa printf(3)
128 */
129 __must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
130 {
131 char *msg;
132
133 PARA_VSPRINTF(fmt, msg);
134 return msg;
135 }
136
137 /**
138 * paraslash's version of strcat()
139 *
140 * \param a string to be appended to
141 * \param b string to append
142 *
143 * Append \p b to \p a.
144 *
145 * \return If \p a is NULL, return a pointer to a copy of \p b, i.e.
146 * para_strcat(NULL, b) is equivalent to para_strdup(b). If \p b is NULL,
147 * return \p a without making a copy of \p a. Otherwise, construct the
148 * concatenation \p c, free \p a (but not \p b) and return \p c.
149 *
150 * \sa strcat(3)
151 */
152 __must_check __malloc char *para_strcat(char *a, const char *b)
153 {
154 char *tmp;
155
156 if (!a)
157 return para_strdup(b);
158 if (!b)
159 return a;
160 tmp = make_message("%s%s", a, b);
161 free(a);
162 return tmp;
163 }
164
165 /**
166 * Paraslash's version of dirname().
167 *
168 * \param name Pointer to the full path.
169 *
170 * Compute the directory component of \p name.
171 *
172 * \return If \p name is \p NULL or the empty string, return \p NULL.
173 * Otherwise, Make a copy of \p name and return its directory component. Caller
174 * is responsible to free the result.
175 */
176 __must_check __malloc char *para_dirname(const char *name)
177 {
178 char *p, *ret;
179
180 if (!name || !*name)
181 return NULL;
182 ret = para_strdup(name);
183 p = strrchr(ret, '/');
184 if (!p)
185 *ret = '\0';
186 else
187 *p = '\0';
188 return ret;
189 }
190
191 /**
192 * Paraslash's version of basename().
193 *
194 * \param name Pointer to the full path.
195 *
196 * Compute the filename component of \a name.
197 *
198 * \return \p NULL if (a) \a name is the empty string of \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.
201 */
202 __must_check const char *para_basename(const char *name)
203 {
204 const char *ret;
205
206 if (!name || !*name)
207 return NULL;
208 ret = strrchr(name, '/');
209 if (!ret)
210 return name;
211 ret++;
212 return ret;
213 }
214
215 /**
216 * cut trailing newline
217 *
218 * \param buf the string to be chopped.
219 *
220 * Replace the last character in \p buf by zero if it is euqal to
221 * the newline character.
222 */
223 void chop(char *buf)
224 {
225 int n = strlen(buf);
226 if (!n)
227 return;
228 if (buf[n - 1] == '\n')
229 buf[n - 1] = '\0';
230 }
231
232 /**
233 * get a random filename
234 *
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
238 * caller.
239 *
240 * \return a pointer to a random filename.
241 */
242 __must_check __malloc char *para_tmpname(void)
243 {
244 struct timeval now;
245 unsigned int seed;
246
247 gettimeofday(&now, NULL);
248 seed = now.tv_usec;
249 srand(seed);
250 return make_message("%08i", rand());
251 }
252
253 /**
254 * create unique temporary file
255 *
256 * \param template the template to be passed to mkstemp()
257 * \param mode the desired mode of the tempfile
258 *
259 * This wrapper for mkstemp additionally uses fchmod() to
260 * set the given mode of the tempfile if mkstemp() returned success.
261 *
262 * \return The file descriptor of the temp file just created on success.
263 * On errors, a negative value is returned.
264 */
265 __must_check int para_mkstemp(char *template, mode_t mode)
266 {
267 int tmp, fd = mkstemp(template);
268
269 if (fd < 0)
270 return -ERRNO_TO_PARA_ERROR(errno);
271 tmp = fchmod(fd, mode);
272 if (tmp >= 0)
273 return fd;
274 tmp = errno;
275 close(fd);
276 unlink(template);
277 return -ERRNO_TO_PARA_ERROR(tmp);
278 }
279
280 /**
281 * get the logname of the current user
282 *
283 * \return A dynammically allocated string that must be freed by the caller. On
284 * errors, the string "unknown user" is returned, i.e. this function never
285 * returns NULL.
286 *
287 * \sa getpwuid(3)
288 */
289 __must_check __malloc char *para_logname(void)
290 {
291 struct passwd *pw = getpwuid(getuid());
292 return para_strdup(pw? pw->pw_name : "unknown_user");
293 }
294
295 /**
296 * get the home directory of the current user
297 *
298 * \return A dynammically allocated string that must be freed by the caller. If
299 * the home directory could not be found, this function returns "/tmp".
300 */
301 __must_check __malloc char *para_homedir(void)
302 {
303 struct passwd *pw = getpwuid(getuid());
304 return para_strdup(pw? pw->pw_dir : "/tmp");
305 }
306
307 /**
308 * split string and return pointers to its parts.
309 *
310 * \param args the string to be split
311 * \param argv_ptr pointer to the list of substrings
312 * \param delim delimiter
313 *
314 * This function modifies \a args by replacing each occurance of \a delim by
315 * zero. A \p NULL-terminated array of pointers to char* is allocated dynamically
316 * and these pointers are initialized to point to the broken-up substrings
317 * within \a args. A pointer to this array is returned via \a argv_ptr. It's OK
318 * to call this function with \a args \a == \p NULL.
319 *
320 * \return The number of substrings found in \a args.
321 */
322 __must_check unsigned split_args(char *args, char *** const argv_ptr, const char *delim)
323 {
324 char *p = args;
325 char **argv;
326 size_t n = 0, i, j;
327
328 p = args + strspn(args, delim);
329 for (;;) {
330 i = strcspn(p, delim);
331 if (!i)
332 break;
333 p += i;
334 n++;
335 p += strspn(p, delim);
336 }
337 *argv_ptr = para_malloc((n + 1) * sizeof(char *));
338 argv = *argv_ptr;
339 i = 0;
340 p = args + strspn(args, delim);
341 while (p) {
342 argv[i] = p;
343 j = strcspn(p, delim);
344 if (!j)
345 break;
346 p += strcspn(p, delim);
347 if (*p) {
348 *p = '\0';
349 p++;
350 p += strspn(p, delim);
351 }
352 i++;
353 }
354 argv[n] = NULL;
355 return n;
356 }
357
358 /**
359 * ensure that file descriptors 0, 1, and 2 are valid
360 *
361 * Common approach that opens /dev/null until it gets a file descriptor greater
362 * than two.
363 *
364 * \sa okir's Black Hats Manual.
365 */
366 void valid_fd_012(void)
367 {
368 while (1) {
369 int fd;
370
371 fd = open("/dev/null", O_RDWR);
372 if (fd < 0)
373 exit(EXIT_FAILURE);
374 if (fd > 2) {
375 close(fd);
376 break;
377 }
378 }
379 }
380
381 /**
382 * get the own hostname
383 *
384 * \return A dynammically allocated string containing the hostname.
385 *
386 * \sa uname(2)
387 */
388 __malloc char *para_hostname(void)
389 {
390 struct utsname u;
391
392 uname(&u);
393 return para_strdup(u.nodename);
394 }
395
396 /**
397 * Used to distinguish between read-only and read-write mode.
398 *
399 * \sa for_each_line(), for_each_line_ro().
400 */
401 enum for_each_line_modes{
402 /** Activate read-only mode. */
403 LINE_MODE_RO,
404 /** Activate read-write mode. */
405 LINE_MODE_RW
406 };
407
408 static int for_each_complete_line(enum for_each_line_modes mode, char *buf,
409 size_t size, line_handler_t *line_handler, void *private_data)
410 {
411 char *start = buf, *end;
412 int ret, i, num_lines = 0;
413
414 // PARA_NOTICE_LOG("buf: %s\n", buf);
415 while (start < buf + size) {
416 char *next_null;
417 char *next_cr;
418
419 next_cr = memchr(start, '\n', buf + size - start);
420 next_null = memchr(start, '\0', buf + size - start);
421 if (!next_cr && !next_null)
422 break;
423 if (next_cr && next_null) {
424 end = next_cr < next_null? next_cr : next_null;
425 } else if (next_null) {
426 end = next_null;
427 } else
428 end = next_cr;
429 num_lines++;
430 if (!line_handler) {
431 start = ++end;
432 continue;
433 }
434 if (mode == LINE_MODE_RO) {
435 size_t s = end - start;
436 char *b = para_malloc(s + 1);
437 memcpy(b, start, s);
438 b[s] = '\0';
439 // PARA_NOTICE_LOG("b: %s, start: %s\n", b, start);
440 ret = line_handler(b, private_data);
441 free(b);
442 } else {
443 *end = '\0';
444 ret = line_handler(start, private_data);
445 }
446 if (ret < 0)
447 return ret;
448 start = ++end;
449 }
450 if (!line_handler || mode == LINE_MODE_RO)
451 return num_lines;
452 i = buf + size - start;
453 if (i && i != size)
454 memmove(buf, start, i);
455 return i;
456 }
457
458 /**
459 * Call a custom function for each complete line.
460 *
461 * \param buf The buffer containing data seperated by newlines.
462 * \param size The number of bytes in \a buf.
463 * \param line_handler The custom function.
464 * \param private_data Pointer passed to \a line_handler.
465 *
466 * If \p line_handler is \p NULL, the function returns the number of complete
467 * lines in \p buf. Otherwise, \p line_handler is called for each complete
468 * line in \p buf. The first argument to \p line_handler is the current line,
469 * and \p private_data is passed as the second argument. The function returns
470 * if \p line_handler returns a negative value or no more lines are in the
471 * buffer. The rest of the buffer (last chunk containing an incomplete line)
472 * is moved to the beginning of the buffer.
473 *
474 * \return If \p line_handler is not \p NULL, this function returns the number
475 * of bytes not handled to \p line_handler on success, or the negative return
476 * value of the \p line_handler on errors.
477 *
478 * \sa for_each_line_ro().
479 */
480 int for_each_line(char *buf, size_t size, line_handler_t *line_handler,
481 void *private_data)
482 {
483 return for_each_complete_line(LINE_MODE_RW, buf, size, line_handler,
484 private_data);
485 }
486
487 /**
488 * Call a custom function for each complete line.
489 *
490 * \param buf Same meaning as in \p for_each_line().
491 * \param size Same meaning as in \p for_each_line().
492 * \param line_handler Same meaning as in \p for_each_line().
493 * \param private_data Same meaning as in \p for_each_line().
494 *
495 * This function behaves like \p for_each_line(), but \a buf is left unchanged.
496 *
497 * \return On success, the function returns the number of complete lines in \p
498 * buf, otherwise the (negative) return value of \p line_handler is returned.
499 *
500 * \sa for_each_line().
501 */
502 int for_each_line_ro(char *buf, size_t size, line_handler_t *line_handler,
503 void *private_data)
504 {
505 return for_each_complete_line(LINE_MODE_RO, buf, size, line_handler,
506 private_data);
507 }
508
509 /**
510 * Safely print into a buffer at a given offset
511 *
512 * \param b Determines the buffer, its size, and the offset.
513 * \param fmt The format string.
514 *
515 * This function prints into the buffer given by \a b at the offset which is
516 * also given by \a b. If there is not enough space to hold the result, the
517 * buffer size is doubled until the underlying call to vsnprintf() succeeds.
518 * Upon return, the offset of \a b is adjusted accordingly so that subsequent
519 * calls to this function append data to what is already contained in the
520 * buffer.
521 *
522 * It's OK to call this function with \p b->buf being \p NULL. In this case, an
523 * initial buffer is allocated.
524 *
525 * \return The number of bytes printed into the buffer (not including the
526 * therminating \p NULL byte).
527 *
528 * \sa make_message(), vsnprintf(3).
529 */
530 __printf_2_3 int para_printf(struct para_buffer *b, const char *fmt, ...)
531 {
532 int ret;
533
534 if (!b->buf) {
535 b->buf = para_malloc(128);
536 b->size = 128;
537 b->offset = 0;
538 } else if (b->size <= b->offset + 1) {
539 b->size *= 2;
540 b->buf = para_realloc(b->buf, b->size);
541 }
542 while (1) {
543 char *p = b->buf + b->offset;
544 size_t size = b->size - b->offset;
545 va_list ap;
546 va_start(ap, fmt);
547 ret = vsnprintf(p, size, fmt, ap);
548 va_end(ap);
549 if (ret > -1 && ret < size) { /* success */
550 b->offset += ret;
551 break;
552 }
553 /* try again with more space */
554 b->size *= 2;
555 b->buf = para_realloc(b->buf, b->size);
556 }
557 return ret;
558 }
559
560 /** \cond LLONG_MAX and LLONG_LIN might not be defined. */
561 #ifndef LLONG_MAX
562 #define LLONG_MAX (1 << (sizeof(long) - 1))
563 #endif
564 #ifndef LLONG_MIN
565 #define LLONG_MIN (-LLONG_MAX - 1LL)
566 #endif
567 /** \endcond */
568
569 /**
570 * Convert a string to a 64-bit signed integer value.
571 *
572 * \param str The string to be converted.
573 * \param value Result pointer.
574 *
575 * \return Positive on success, negative on errors.
576 *
577 * \sa para_atoi32(), strtol(3), atoi(3).
578 */
579 int para_atoi64(const char *str, int64_t *value)
580 {
581 char *endptr;
582 long long tmp;
583
584 errno = 0; /* To distinguish success/failure after call */
585 tmp = strtoll(str, &endptr, 10);
586 if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
587 return -E_ATOI_OVERFLOW;
588 if (errno != 0 && tmp == 0) /* other error */
589 return -E_STRTOLL;
590 if (endptr == str)
591 return -E_ATOI_NO_DIGITS;
592 if (*endptr != '\0') /* Further characters after number */
593 return -E_ATOI_JUNK_AT_END;
594 *value = tmp;
595 return 1;
596 }
597
598 /**
599 * Convert a string to a 32-bit signed integer value.
600 *
601 * \param str The string to be converted.
602 * \param value Result pointer.
603 *
604 * \return Positive on success, negative on errors.
605 *
606 * \sa para_atoi64().
607 */
608 int para_atoi32(const char *str, int32_t *value)
609 {
610 int64_t tmp;
611 int ret;
612 const int32_t max = 2147483647;
613
614 ret = para_atoi64(str, &tmp);
615 if (ret < 0)
616 return ret;
617 if (tmp > max || tmp < -max - 1)
618 return -E_ATOI_OVERFLOW;
619 *value = tmp;
620 return 1;
621 }