1 /* vi: set sw=4 ts=4: */
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6 * Copyright (C) 2006 Rob Landley
7 * Copyright (C) 2006 Denis Vlasenko
9 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
14 /* All the functions starting with "x" call bb_error_msg_and_die() if they
15 * fail, so callers never need to check for errors. If it returned, it
19 /* dmalloc provides variants of these that do abort() on failure.
20 * Since dmalloc's prototypes overwrite the impls here as they are
21 * included after these prototypes in libbb.h, all is well.
24 /* Die if we can't allocate size bytes of memory. */
25 void *xmalloc(size_t size)
27 void *ptr = malloc(size);
28 if (ptr == NULL && size != 0)
29 bb_error_msg_and_die(bb_msg_memory_exhausted);
35 /* Die if we can't resize previously allocated memory. (This returns a pointer
36 * to the new memory, which may or may not be the same as the old memory.
37 * It'll copy the contents to a new chunk and free the old one if necessary.) */
38 void *xrealloc(void *ptr, size_t size)
40 ptr = realloc(ptr, size);
41 if (ptr == NULL && size != 0)
42 bb_error_msg_and_die(bb_msg_memory_exhausted);
50 /* Die if we can't allocate and zero size bytes of memory. */
51 void *xzalloc(size_t size)
53 void *ptr = xmalloc(size);
60 /* Die if we can't copy a string to freshly allocated memory. */
61 char * xstrdup(const char *s)
71 bb_error_msg_and_die(bb_msg_memory_exhausted);
78 /* Die if we can't allocate n+1 bytes (space for the null terminator) and copy
79 * the (possibly truncated to length n) string into it.
81 char * xstrndup(const char *s, int n)
85 if (ENABLE_DEBUG && s == NULL)
86 bb_error_msg_and_die("xstrndup bug");
90 return safe_strncpy(t,s,n);
95 /* Die if we can't open a file and return a FILE * to it.
96 * Notice we haven't got xfread(), This is for use with fscanf() and friends.
98 FILE *xfopen(const char *path, const char *mode)
101 if ((fp = fopen(path, mode)) == NULL)
102 bb_perror_msg_and_die("%s", path);
108 /* Die if we can't open an existing file and return an fd. */
109 int xopen(const char *pathname, int flags)
111 if (ENABLE_DEBUG && (flags && O_CREAT))
112 bb_error_msg_and_die("xopen() with O_CREAT\n");
114 return xopen3(pathname, flags, 0777);
119 /* Die if we can't open a new file and return an fd. */
120 int xopen3(const char *pathname, int flags, int mode)
124 ret = open(pathname, flags, mode);
126 bb_perror_msg_and_die("%s", pathname);
133 /* Die with an error message if we can't read the entire buffer. */
134 void xread(int fd, void *buf, size_t count)
139 if ((size = safe_read(fd, buf, count)) < 1)
140 bb_error_msg_and_die("Short read");
142 buf = ((char *) buf) + size;
148 /* Die with an error message if we can't write the entire buffer. */
149 void xwrite(int fd, void *buf, size_t count)
154 if ((size = safe_write(fd, buf, count)) < 1)
155 bb_error_msg_and_die("Short write");
157 buf = ((char *) buf) + size;
163 /* Die with an error message if we can't lseek to the right spot. */
164 void xlseek(int fd, off_t offset, int whence)
166 if (offset != lseek(fd, offset, whence)) bb_error_msg_and_die("lseek");
171 /* Die with an error message if we can't read one character. */
172 unsigned char xread_char(int fd)
183 /* Die with supplied error message if this FILE * has ferror set. */
184 void xferror(FILE *fp, const char *fn)
187 bb_error_msg_and_die("%s", fn);
192 #ifdef L_xferror_stdout
193 /* Die with an error message if stdout has ferror set. */
194 void xferror_stdout(void)
196 xferror(stdout, bb_msg_standard_output);
200 #ifdef L_xfflush_stdout
201 /* Die with an error message if we have trouble flushing stdout. */
202 void xfflush_stdout(void)
204 if (fflush(stdout)) {
205 bb_perror_msg_and_die(bb_msg_standard_output);
211 /* This does a fork/exec in one call, using vfork(). Return PID of new child,
212 * -1 for failure. Runs argv[0], searching path if that has no / in it.
214 pid_t spawn(char **argv)
218 void *app = ENABLE_FEATURE_SH_STANDALONE_SHELL ? find_applet_by_name(argv[0]) : 0;
220 /* Be nice to nommu machines. */
223 if (pid < 0) return pid;
225 execvp(app ? CONFIG_BUSYBOX_EXEC_PATH : *argv, argv);
227 /* We're sharing a stack with blocked parent, let parent know we failed
228 * and then exit to unblock parent (but don't run atexit() stuff, which
229 would screw up parent.) */
234 return failed ? failed : pid;
239 /* Die with an error message if we can't spawn a child process. */
240 pid_t xspawn(char **argv)
242 pid_t pid = spawn(argv);
243 if (pid < 0) bb_perror_msg_and_die("%s", *argv);
249 /* Wait for the specified child PID to exit, returning child's error return. */
250 int wait4pid(int pid)
254 if (pid == -1 || waitpid(pid, &status, 0) == -1) return -1;
255 if (WIFEXITED(status)) return WEXITSTATUS(status);
256 if (WIFSIGNALED(status)) return WTERMSIG(status);
262 /* Convert unsigned integer to ascii, writing into supplied buffer. A
263 * truncated result is always null terminated (unless buflen is 0), and
264 * contains the first few digits of the result ala strncpy. */
265 void utoa_to_buf(unsigned n, char *buf, unsigned buflen)
269 for (i=1000000000; i; i/=10) {
272 if ((res || out || i == 1) && --buflen>0) {
282 /* Convert signed integer to ascii, like utoa_to_buf() */
283 void itoa_to_buf(int n, char *buf, unsigned buflen)
290 utoa_to_buf((unsigned)n, buf, buflen);
293 /* The following two functions use a static buffer, so calling either one a
294 * second time will overwrite previous results.
296 * The largest 32 bit integer is -2 billion plus null terminator, or 12 bytes.
297 * Int should always be 32 bits on any remotely Unix-like system, see
298 * http://www.unix.org/whitepapers/64bit.html for the reasons why.
300 static char local_buf[12];
302 /* Convert unsigned integer to ascii using a static buffer (returned). */
303 char *utoa(unsigned n)
305 utoa_to_buf(n, local_buf, sizeof(local_buf));
310 /* Convert signed integer to ascii using a static buffer (returned). */
313 itoa_to_buf(n, local_buf, sizeof(local_buf));
320 /* Die with an error message if we can't set gid. (Because resource limits may
321 * limit this user to a given number of processes, and if that fills up the
322 * setgid() will fail and we'll _still_be_root_, which is bad.) */
323 void xsetgid(gid_t gid)
325 if (setgid(gid)) bb_error_msg_and_die("setgid");
328 /* Die with an error message if we cant' set uid. (See xsetgid() for why.) */
329 void xsetuid(uid_t uid)
331 if (setuid(uid)) bb_error_msg_and_die("setuid");
336 /* Return how long the file at fd is, if there's any way to determine it. */
337 off_t fdlength(int fd)
339 off_t bottom = 0, top = 0, pos;
342 /* If the ioctl works for this, return it. */
344 if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
346 /* If not, do a binary search for the last location we can read. (Some
347 * block devices don't do BLKGETSIZE right.) */
352 pos = bottom + (top - bottom) / 2;;
354 /* If we can read from the current location, it's bigger. */
356 if (lseek(fd, pos, 0)>=0 && safe_read(fd, &temp, 1)==1) {
357 if (bottom == top) bottom = top = (top+1) * 2;
360 /* If we can't, it's smaller. */
369 } while (bottom + 1 != top);
376 /* Die with an error message if we can't malloc() enough space and do an
377 * sprintf() into that space. */
378 char *xasprintf(const char *format, ...)
387 r = vasprintf(&string_ptr, format, p);
390 // Bloat for systems that haven't got the GNU extension.
392 r = vsnprintf(NULL, 0, format, p);
394 string_ptr = xmalloc(r+1);
396 r = vsnprintf(string_ptr, r+1, format, p);
400 if (r < 0) bb_perror_msg_and_die("xasprintf");
405 #ifdef L_xprint_and_close_file
406 /* Die with an error message if we can't copy an entire FILE * to stdout, then
407 * close that file. */
408 void xprint_and_close_file(FILE *file)
410 // copyfd outputs error messages for us.
411 if (bb_copyfd_eof(fileno(file), 1) == -1) exit(bb_default_error_retval);
418 /* Die if we can't chdir to a new path. */
419 void xchdir(const char *path)
422 bb_perror_msg_and_die("chdir(%s)", path);
426 #ifdef L_warn_opendir
427 /* Print a warning message if opendir() fails, but don't die. */
428 DIR *warn_opendir(const char *path)
432 if ((dp = opendir(path)) == NULL) {
433 bb_perror_msg("unable to open `%s'", path);
441 /* Die with an error message if opendir() fails. */
442 DIR *xopendir(const char *path)
446 if ((dp = opendir(path)) == NULL)
447 bb_perror_msg_and_die("unable to open `%s'", path);
454 /* Die with an error message if we can't daemonize. */
455 void xdaemon(int nochdir, int noclose)
457 if (daemon(nochdir, noclose)) bb_perror_msg_and_die("daemon");
463 /* Die with an error message if we can't open a new socket. */
464 int xsocket(int domain, int type, int protocol)
466 int r = socket(domain, type, protocol);
468 if (r < 0) bb_perror_msg_and_die("socket");
475 /* Die with an error message if we can't bind a socket to an address. */
476 void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen)
478 if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind");
483 /* Die with an error message if we can't listen for connections on a socket. */
484 void xlisten(int s, int backlog)
486 if (listen(s, backlog)) bb_perror_msg_and_die("listen");