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.
80 char * xstrndup(const char *s, int n)
84 if (ENABLE_DEBUG && s == NULL)
85 bb_error_msg_and_die("xstrndup bug");
89 return safe_strncpy(t,s,n);
94 // Die if we can't open a file and return a FILE * to it.
95 // Notice we haven't got xfread(), This is for use with fscanf() and friends.
96 FILE *xfopen(const char *path, const char *mode)
99 if ((fp = fopen(path, mode)) == NULL)
100 bb_perror_msg_and_die("%s", path);
106 // Die if we can't open an existing file and return an fd.
107 int xopen(const char *pathname, int flags)
109 if (ENABLE_DEBUG && (flags & O_CREAT))
110 bb_error_msg_and_die("xopen() with O_CREAT");
112 return xopen3(pathname, flags, 0777);
117 // Die if we can't open a new file and return an fd.
118 int xopen3(const char *pathname, int flags, int mode)
122 ret = open(pathname, flags, mode);
124 bb_perror_msg_and_die("%s", pathname);
131 // Die with an error message if we can't read the entire buffer.
132 void xread(int fd, void *buf, size_t count)
137 if ((size = safe_read(fd, buf, count)) < 1)
138 bb_error_msg_and_die("Short read");
140 buf = ((char *) buf) + size;
146 // Die with an error message if we can't write the entire buffer.
147 void xwrite(int fd, void *buf, size_t count)
152 if ((size = safe_write(fd, buf, count)) < 1)
153 bb_error_msg_and_die("Short write");
155 buf = ((char *) buf) + size;
161 // Die with an error message if we can't lseek to the right spot.
162 void xlseek(int fd, off_t offset, int whence)
164 if (offset != lseek(fd, offset, whence)) bb_error_msg_and_die("lseek");
169 // Die with an error message if we can't read one character.
170 unsigned char xread_char(int fd)
181 // Die with supplied error message if this FILE * has ferror set.
182 void xferror(FILE *fp, const char *fn)
185 bb_error_msg_and_die("%s", fn);
190 #ifdef L_xferror_stdout
191 // Die with an error message if stdout has ferror set.
192 void xferror_stdout(void)
194 xferror(stdout, bb_msg_standard_output);
198 #ifdef L_xfflush_stdout
199 // Die with an error message if we have trouble flushing stdout.
200 void xfflush_stdout(void)
202 if (fflush(stdout)) {
203 bb_perror_msg_and_die(bb_msg_standard_output);
209 // This does a fork/exec in one call, using vfork(). Return PID of new child,
210 // -1 for failure. Runs argv[0], searching path if that has no / in it.
211 pid_t spawn(char **argv)
215 void *app = ENABLE_FEATURE_SH_STANDALONE_SHELL ? find_applet_by_name(argv[0]) : 0;
217 // Be nice to nommu machines.
220 if (pid < 0) return pid;
222 execvp(app ? CONFIG_BUSYBOX_EXEC_PATH : *argv, argv);
224 // We're sharing a stack with blocked parent, let parent know we failed
225 // and then exit to unblock parent (but don't run atexit() stuff, which
226 // would screw up parent.)
231 return failed ? failed : pid;
236 // Die with an error message if we can't spawn a child process.
237 pid_t xspawn(char **argv)
239 pid_t pid = spawn(argv);
240 if (pid < 0) bb_perror_msg_and_die("%s", *argv);
246 // Wait for the specified child PID to exit, returning child's error return.
247 int wait4pid(int pid)
251 if (pid == -1 || waitpid(pid, &status, 0) == -1) return -1;
252 if (WIFEXITED(status)) return WEXITSTATUS(status);
253 if (WIFSIGNALED(status)) return WTERMSIG(status);
259 // Convert unsigned integer to ascii, writing into supplied buffer. A
260 // truncated result is always null terminated (unless buflen is 0), and
261 // contains the first few digits of the result ala strncpy.
262 void utoa_to_buf(unsigned n, char *buf, unsigned buflen)
266 for (i=1000000000; i; i/=10) {
269 if ((res || out || i == 1) && --buflen>0) {
279 // Convert signed integer to ascii, like utoa_to_buf()
280 void itoa_to_buf(int n, char *buf, unsigned buflen)
287 utoa_to_buf((unsigned)n, buf, buflen);
290 // The following two functions use a static buffer, so calling either one a
291 // second time will overwrite previous results.
293 // The largest 32 bit integer is -2 billion plus null terminator, or 12 bytes.
294 // Int should always be 32 bits on any remotely Unix-like system, see
295 // http://www.unix.org/whitepapers/64bit.html for the reasons why.
297 static char local_buf[12];
299 // Convert unsigned integer to ascii using a static buffer (returned).
300 char *utoa(unsigned n)
302 utoa_to_buf(n, local_buf, sizeof(local_buf));
307 // Convert signed integer to ascii using a static buffer (returned).
310 itoa_to_buf(n, local_buf, sizeof(local_buf));
317 // Die with an error message if we can't set gid. (Because resource limits may
318 // limit this user to a given number of processes, and if that fills up the
319 // setgid() will fail and we'll _still_be_root_, which is bad.)
320 void xsetgid(gid_t gid)
322 if (setgid(gid)) bb_error_msg_and_die("setgid");
325 // Die with an error message if we cant' set uid. (See xsetgid() for why.)
326 void xsetuid(uid_t uid)
328 if (setuid(uid)) bb_error_msg_and_die("setuid");
333 // Return how long the file at fd is, if there's any way to determine it.
334 off_t fdlength(int fd)
336 off_t bottom = 0, top = 0, pos;
339 // If the ioctl works for this, return it.
341 if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
343 // If not, do a binary search for the last location we can read. (Some
344 // block devices don't do BLKGETSIZE right.)
349 pos = bottom + (top - bottom) / 2;
351 // If we can read from the current location, it's bigger.
353 if (lseek(fd, pos, 0)>=0 && safe_read(fd, &temp, 1)==1) {
354 if (bottom == top) bottom = top = (top+1) * 2;
357 // If we can't, it's smaller.
366 } while (bottom + 1 != top);
373 // Die with an error message if we can't malloc() enough space and do an
374 // sprintf() into that space.
375 char *xasprintf(const char *format, ...)
384 r = vasprintf(&string_ptr, format, p);
387 // Bloat for systems that haven't got the GNU extension.
389 r = vsnprintf(NULL, 0, format, p);
391 string_ptr = xmalloc(r+1);
393 r = vsnprintf(string_ptr, r+1, format, p);
397 if (r < 0) bb_error_msg_and_die(bb_msg_memory_exhausted);
402 #ifdef L_xprint_and_close_file
403 // Die with an error message if we can't copy an entire FILE * to stdout, then
405 void xprint_and_close_file(FILE *file)
407 // copyfd outputs error messages for us.
408 if (bb_copyfd_eof(fileno(file), 1) == -1)
409 exit(bb_default_error_retval);
416 // Die if we can't chdir to a new path.
417 void xchdir(const char *path)
420 bb_perror_msg_and_die("chdir(%s)", path);
424 #ifdef L_warn_opendir
425 // Print a warning message if opendir() fails, but don't die.
426 DIR *warn_opendir(const char *path)
430 if ((dp = opendir(path)) == NULL) {
431 bb_perror_msg("unable to open `%s'", path);
439 // Die with an error message if opendir() fails.
440 DIR *xopendir(const char *path)
444 if ((dp = opendir(path)) == NULL)
445 bb_perror_msg_and_die("unable to open `%s'", path);
452 // Die with an error message if we can't daemonize.
453 void xdaemon(int nochdir, int noclose)
455 if (daemon(nochdir, noclose)) bb_perror_msg_and_die("daemon");
461 // Die with an error message if we can't open a new socket.
462 int xsocket(int domain, int type, int protocol)
464 int r = socket(domain, type, protocol);
466 if (r < 0) bb_perror_msg_and_die("socket");
473 // Die with an error message if we can't bind a socket to an address.
474 void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen)
476 if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind");
481 // Die with an error message if we can't listen for connections on a socket.
482 void xlisten(int s, int backlog)
484 if (listen(s, backlog)) bb_perror_msg_and_die("listen");
489 // xstat() - a stat() which dies on failure with meaningful error message
490 void xstat(char *name, struct stat *stat_buf)
492 if (stat(name, stat_buf))
493 bb_perror_msg_and_die("Can't stat '%s'", name);