2 * Copyright (C) 2004-2007 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 NULL
23 * \param size 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 \p 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 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("%s", "malloc failed, aborting\n");
73 * paraslash's version of calloc()
75 * \param size desired new size
77 * A wrapper for calloc(3) which exits on errors.
79 * \return A pointer to the allocated and zeroed-out memory, which is suitably
80 * aligned for any kind of variable.
84 __must_check __malloc
void *para_calloc(size_t size
)
86 void *ret
= para_malloc(size
);
93 * paraslash's version of strdup()
95 * \param s string to be duplicated
97 * A wrapper for strdup(3). It calls \p exit(EXIT_FAILURE) on errors, i.e.
98 * there is no need to check the return value in the caller.
100 * \return A pointer to the duplicated string. If \p s was the NULL pointer,
101 * an pointer to an empty string is returned.
105 __must_check __malloc
char *para_strdup(const char *s
)
109 if ((ret
= strdup(s
? s
: "")))
111 PARA_EMERG_LOG("%s", "strdup failed, aborting\n");
116 * allocate a sufficiently large string and print into it
118 * \param fmt usual format string
120 * Produce output according to \p fmt. No artificial bound on the length of the
121 * resulting string is imposed.
123 * \return This function either returns a pointer to a string that must be
124 * freed by the caller or aborts without returning.
128 __must_check __printf_1_2 __malloc
char *make_message(const char *fmt
, ...)
132 PARA_VSPRINTF(fmt
, msg
);
137 * paraslash's version of strcat()
139 * \param a string to be appended to
140 * \param b string to append
142 * Append \p b to \p a.
144 * \return If \p a is NULL, return a pointer to a copy of \p b, i.e.
145 * para_strcat(NULL, b) is equivalent to para_strdup(b). If \p b is NULL,
146 * return \p a without making a copy of \p a. Otherwise, construct the
147 * concatenation \p c, free \p a (but not \p b) and return \p c.
151 __must_check __malloc
char *para_strcat(char *a
, const char *b
)
156 return para_strdup(b
);
159 tmp
= make_message("%s%s", a
, b
);
165 * paraslash's version of dirname()
167 * \param name pointer to the full path
169 * Compute the directory component of \p name
171 * \return If \p name is \รพ NULL or the empty string, return \p NULL.
172 * Otherwise, Make a copy of \p name and return its directory component. Caller
173 * is responsible to free the result.
175 __must_check __malloc
char *para_dirname(const char *name
)
181 ret
= para_strdup(name
);
182 p
= strrchr(ret
, '/');
191 * paraslash's version of basename()
193 * \param name Pointer to the full path
195 * Compute the filename component of \p name
197 * \return If \p name is \p NULL or the empty string, return \p NULL,
198 * Otherwise, make a copy of \p name and return its filename component. Caller
199 * is responsible to free the result.
201 __must_check __malloc
char *para_basename(const char *name
)
207 p
= strrchr(name
, '/');
209 return para_strdup(name
);
213 return para_strdup(p
);
217 * cut trailing newline
219 * \param buf the string to be chopped.
221 * Replace the last character in \p buf by zero if it is euqal to
222 * the newline character.
229 if (buf
[n
- 1] == '\n')
234 * get a random filename
236 * This is by no means a secure way to create temporary files in a hostile
237 * direcory like \p /tmp. However, it is OK to use for temp files, fifos,
238 * sockets that are created in ~/.paraslash. Result must be freed by the
241 * \return a pointer to a random filename.
243 __must_check __malloc
char *para_tmpname(void)
248 gettimeofday(&now
, NULL
);
251 return make_message("%08i", rand());
255 * create unique temporary file
257 * \param template the template to be passed to mkstemp()
258 * \param mode the desired mode of the tempfile
260 * This wrapper for mkstemp additionally uses fchmod() to
261 * set the given mode of the tempfile if mkstemp() returned success.
263 * \return The file descriptor of the temp file just created on success.
264 * On errors, -E_MKSTEMP or -E_FCHMOD is returned.
266 __must_check
int para_mkstemp(char *template, mode_t mode
)
268 int tmp
, fd
= mkstemp(template);
272 tmp
= fchmod(fd
, mode
);
281 * get the logname of the current user
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
289 __must_check __malloc
char *para_logname(void)
291 struct passwd
*pw
= getpwuid(getuid());
292 return para_strdup(pw
? pw
->pw_name
: "unknown_user");
296 * get the home directory of the current user
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".
301 __must_check __malloc
char *para_homedir(void)
303 struct passwd
*pw
= getpwuid(getuid());
304 return para_strdup(pw
? pw
->pw_dir
: "/tmp");
308 * split string and return pointers to its parts.
310 * \param args the string to be split
311 * \param argv_ptr pointer to the list of substrings
312 * \param delim delimiter
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.
320 * \return The number of substrings found in \a args.
322 __must_check
unsigned split_args(char *args
, char *** const argv_ptr
, const char *delim
)
328 p
= args
+ strspn(args
, delim
);
330 i
= strcspn(p
, delim
);
335 p
+= strspn(p
, delim
);
337 *argv_ptr
= para_malloc((n
+ 1) * sizeof(char *));
340 p
= args
+ strspn(args
, delim
);
343 j
= strcspn(p
, delim
);
346 p
+= strcspn(p
, delim
);
350 p
+= strspn(p
, delim
);
359 * ensure that file descriptors 0, 1, and 2 are valid
361 * Common approach that opens /dev/null until it gets a file descriptor greater
364 * \sa okir's Black Hats Manual.
366 void valid_fd_012(void)
371 fd
= open("/dev/null", O_RDWR
);
382 * get the own hostname
384 * \return A dynammically allocated string containing the hostname.
388 __malloc
char *para_hostname(void)
393 return para_strdup(u
.nodename
);
396 enum for_each_line_modes
{LINE_MODE_RO
, LINE_MODE_RW
};
398 static int for_each_complete_line(enum for_each_line_modes mode
, char *buf
,
399 size_t size
, line_handler_t
*line_handler
, void *private_data
)
401 char *start
= buf
, *end
;
402 int ret
, i
, num_lines
= 0;
404 // PARA_NOTICE_LOG("buf: %s\n", buf);
405 while (start
< buf
+ size
) {
409 next_cr
= memchr(start
, '\n', buf
+ size
- start
);
410 next_null
= memchr(start
, '\0', buf
+ size
- start
);
411 if (!next_cr
&& !next_null
)
413 if (next_cr
&& next_null
) {
414 end
= next_cr
< next_null
? next_cr
: next_null
;
415 } else if (next_null
) {
424 if (mode
== LINE_MODE_RO
) {
425 size_t s
= end
- start
;
426 char *b
= para_malloc(s
+ 1);
429 // PARA_NOTICE_LOG("b: %s, start: %s\n", b, start);
430 ret
= line_handler(b
, private_data
);
434 ret
= line_handler(start
, private_data
);
440 if (!line_handler
|| mode
== LINE_MODE_RO
)
442 i
= buf
+ size
- start
;
444 memmove(buf
, start
, i
);
449 * call a custom function for each complete line
451 * \param buf the buffer containing data seperated by newlines
452 * \param size the number of bytes in \a buf
453 * \param line_handler the custom function
454 * \param private_data pointer to data which is passed to \a line_handler
456 * If \p line_handler is \p NULL, the function returns the number of complete
457 * lines in \p buf. Otherwise, \p line_handler is called for each complete
458 * line in \p buf. The first argument to \p line_handler is the current line,
459 * and \p private_data is passed as the second argument. The function returns
460 * if \p line_handler returns a negative value or no more lines are in the
461 * buffer. The rest of the buffer (last chunk containing an incomplete line)
462 * is moved to the beginning of the buffer.
464 * \return If \p line_handler is not \p NULL, this function returns the number
465 * of bytes not handled to \p line_handler on success, or the negative return
466 * value of the \p line_handler on errors.
468 * \sa for_each_line_ro()
470 int for_each_line(char *buf
, size_t size
, line_handler_t
*line_handler
,
473 return for_each_complete_line(LINE_MODE_RW
, buf
, size
, line_handler
,
478 * call a custom function for each complete line
480 * \param buf same meaning as in \p for_each_line
481 * \param size same meaning as in \p for_each_line
482 * \param line_handler same meaning as in \p for_each_line
483 * \param private_data same meaning as in \p for_each_line
485 * This function behaves like \p for_each_line() with the following differences:
487 * - buf is left unchanged
489 * \return On success, the function returns the number of complete lines in \p
490 * buf, otherwise the (negative) return value of \p line_handler is returned.
492 * \sa for_each_line()
494 int for_each_line_ro(char *buf
, size_t size
, line_handler_t
*line_handler
,
497 return for_each_complete_line(LINE_MODE_RO
, buf
, size
, line_handler
,
502 * Safely print into a buffer at a given offset
504 * \param b Determines the buffer, its size, and the offset.
505 * \param fmt The format string.
507 * This function prints into the buffer given by \a b at the offset which is
508 * also given by \a b. If there is not enough space to hold the result, the
509 * buffer size is doubled until the underlying call to vsnprintf() succeeds.
510 * Upon return, the offset of \a b is adjusted accordingly so that subsequent
511 * calls to this function append data to what is already contained in the
514 * It's OK to call this function with \p b->buf being \p NULL. In this case, an
515 * initial buffer is allocated.
517 * \return The number of bytes printed into the buffer (not including the
518 * therminating \p NULL byte).
520 * \sa make_message(), vsnprintf(3).
522 __printf_2_3
int para_printf(struct para_buffer
*b
, const char *fmt
, ...)
527 b
->buf
= para_malloc(128);
530 } else if (b
->size
<= b
->offset
+ 1) {
532 b
->buf
= para_realloc(b
->buf
, b
->size
);
535 char *p
= b
->buf
+ b
->offset
;
536 size_t size
= b
->size
- b
->offset
;
539 ret
= vsnprintf(p
, size
, fmt
, ap
);
541 if (ret
> -1 && ret
< size
) { /* success */
545 /* try again with more space */
547 b
->buf
= para_realloc(b
->buf
, b
->size
);