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 GPL version 2, 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.
23 // Die if we can't allocate size bytes of memory.
24 void *xmalloc(size_t size)
26 void *ptr = malloc(size);
27 if (ptr == NULL && size != 0)
28 bb_error_msg_and_die(bb_msg_memory_exhausted);
32 // Die if we can't resize previously allocated memory. (This returns a pointer
33 // to the new memory, which may or may not be the same as the old memory.
34 // It'll copy the contents to a new chunk and free the old one if necessary.)
35 void *xrealloc(void *ptr, size_t size)
37 ptr = realloc(ptr, size);
38 if (ptr == NULL && size != 0)
39 bb_error_msg_and_die(bb_msg_memory_exhausted);
44 // Die if we can't allocate and zero size bytes of memory.
45 void *xzalloc(size_t size)
47 void *ptr = xmalloc(size);
52 // Die if we can't copy a string to freshly allocated memory.
53 char * xstrdup(const char *s)
63 bb_error_msg_and_die(bb_msg_memory_exhausted);
68 // Die if we can't allocate n+1 bytes (space for the null terminator) and copy
69 // the (possibly truncated to length n) string into it.
70 char * xstrndup(const char *s, int n)
74 if (ENABLE_DEBUG && s == NULL)
75 bb_error_msg_and_die("xstrndup bug");
79 return safe_strncpy(t,s,n);
82 // Die if we can't open a file and return a FILE * to it.
83 // Notice we haven't got xfread(), This is for use with fscanf() and friends.
84 FILE *xfopen(const char *path, const char *mode)
87 if ((fp = fopen(path, mode)) == NULL)
88 bb_perror_msg_and_die("%s", path);
92 // Die if we can't open an existing file and return an fd.
93 int xopen(const char *pathname, int flags)
95 if (ENABLE_DEBUG && (flags & O_CREAT))
96 bb_error_msg_and_die("xopen() with O_CREAT");
98 return xopen3(pathname, flags, 0666);
101 // Die if we can't open a new file and return an fd.
102 int xopen3(const char *pathname, int flags, int mode)
106 ret = open(pathname, flags, mode);
108 bb_perror_msg_and_die("%s", pathname);
113 // Die with an error message if we can't write the entire buffer.
114 void xwrite(int fd, void *buf, size_t count)
117 ssize_t size = full_write(fd, buf, count);
119 bb_error_msg_and_die("short write");
123 // Die with an error message if we can't lseek to the right spot.
124 off_t xlseek(int fd, off_t offset, int whence)
126 off_t off = lseek(fd, offset, whence);
127 if (off == (off_t)-1)
128 bb_perror_msg_and_die("lseek");
132 // Die with supplied error message if this FILE * has ferror set.
133 void die_if_ferror(FILE *fp, const char *fn)
136 bb_error_msg_and_die("%s", fn);
140 // Die with an error message if stdout has ferror set.
141 void die_if_ferror_stdout(void)
143 die_if_ferror(stdout, bb_msg_standard_output);
146 // Die with an error message if we have trouble flushing stdout.
147 void xfflush_stdout(void)
149 if (fflush(stdout)) {
150 bb_perror_msg_and_die(bb_msg_standard_output);
154 // This does a fork/exec in one call, using vfork(). Return PID of new child,
155 // -1 for failure. Runs argv[0], searching path if that has no / in it.
156 pid_t spawn(char **argv)
160 void *app = ENABLE_FEATURE_SH_STANDALONE_SHELL ? find_applet_by_name(argv[0]) : 0;
162 // Be nice to nommu machines.
165 if (pid < 0) return pid;
167 execvp(app ? CONFIG_BUSYBOX_EXEC_PATH : *argv, argv);
169 // We're sharing a stack with blocked parent, let parent know we failed
170 // and then exit to unblock parent (but don't run atexit() stuff, which
171 // would screw up parent.)
176 return failed ? failed : pid;
179 // Die with an error message if we can't spawn a child process.
180 pid_t xspawn(char **argv)
182 pid_t pid = spawn(argv);
183 if (pid < 0) bb_perror_msg_and_die("%s", *argv);
187 // Wait for the specified child PID to exit, returning child's error return.
188 int wait4pid(int pid)
192 if (pid == -1 || waitpid(pid, &status, 0) == -1) return -1;
193 if (WIFEXITED(status)) return WEXITSTATUS(status);
194 if (WIFSIGNALED(status)) return WTERMSIG(status);
198 void xsetenv(const char *key, const char *value)
200 if (setenv(key, value, 1))
201 bb_error_msg_and_die(bb_msg_memory_exhausted);
204 // Convert unsigned integer to ascii, writing into supplied buffer. A
205 // truncated result is always null terminated (unless buflen is 0), and
206 // contains the first few digits of the result ala strncpy.
207 void utoa_to_buf(unsigned n, char *buf, unsigned buflen)
211 for (i=1000000000; i; i/=10) {
214 if ((res || out || i == 1) && --buflen>0) {
224 // Convert signed integer to ascii, like utoa_to_buf()
225 void itoa_to_buf(int n, char *buf, unsigned buflen)
232 utoa_to_buf((unsigned)n, buf, buflen);
235 // The following two functions use a static buffer, so calling either one a
236 // second time will overwrite previous results.
238 // The largest 32 bit integer is -2 billion plus null terminator, or 12 bytes.
239 // Int should always be 32 bits on any remotely Unix-like system, see
240 // http://www.unix.org/whitepapers/64bit.html for the reasons why.
242 static char local_buf[12];
244 // Convert unsigned integer to ascii using a static buffer (returned).
245 char *utoa(unsigned n)
247 utoa_to_buf(n, local_buf, sizeof(local_buf));
252 // Convert signed integer to ascii using a static buffer (returned).
255 itoa_to_buf(n, local_buf, sizeof(local_buf));
260 // Die with an error message if we can't set gid. (Because resource limits may
261 // limit this user to a given number of processes, and if that fills up the
262 // setgid() will fail and we'll _still_be_root_, which is bad.)
263 void xsetgid(gid_t gid)
265 if (setgid(gid)) bb_error_msg_and_die("setgid");
268 // Die with an error message if we can't set uid. (See xsetgid() for why.)
269 void xsetuid(uid_t uid)
271 if (setuid(uid)) bb_error_msg_and_die("setuid");
274 // Return how long the file at fd is, if there's any way to determine it.
275 off_t fdlength(int fd)
277 off_t bottom = 0, top = 0, pos;
280 // If the ioctl works for this, return it.
282 if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
284 // FIXME: explain why lseek(SEEK_END) is not used here!
286 // If not, do a binary search for the last location we can read. (Some
287 // block devices don't do BLKGETSIZE right.)
292 pos = bottom + (top - bottom) / 2;
294 // If we can read from the current location, it's bigger.
296 if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) {
297 if (bottom == top) bottom = top = (top+1) * 2;
300 // If we can't, it's smaller.
309 } while (bottom + 1 != top);
314 // Die with an error message if we can't malloc() enough space and do an
315 // sprintf() into that space.
316 char *xasprintf(const char *format, ...)
325 r = vasprintf(&string_ptr, format, p);
328 // Bloat for systems that haven't got the GNU extension.
330 r = vsnprintf(NULL, 0, format, p);
332 string_ptr = xmalloc(r+1);
334 r = vsnprintf(string_ptr, r+1, format, p);
338 if (r < 0) bb_error_msg_and_die(bb_msg_memory_exhausted);
342 // Die with an error message if we can't copy an entire FILE * to stdout, then
344 void xprint_and_close_file(FILE *file)
347 // copyfd outputs error messages for us.
348 if (bb_copyfd_eof(fileno(file), 1) == -1)
349 exit(xfunc_error_retval);
354 // Die if we can't chdir to a new path.
355 void xchdir(const char *path)
358 bb_perror_msg_and_die("chdir(%s)", path);
361 // Print a warning message if opendir() fails, but don't die.
362 DIR *warn_opendir(const char *path)
366 if ((dp = opendir(path)) == NULL) {
367 bb_perror_msg("unable to open `%s'", path);
373 // Die with an error message if opendir() fails.
374 DIR *xopendir(const char *path)
378 if ((dp = opendir(path)) == NULL)
379 bb_perror_msg_and_die("unable to open `%s'", path);
384 // Die with an error message if we can't daemonize.
385 void xdaemon(int nochdir, int noclose)
387 if (daemon(nochdir, noclose))
388 bb_perror_msg_and_die("daemon");
392 // Die with an error message if we can't open a new socket.
393 int xsocket(int domain, int type, int protocol)
395 int r = socket(domain, type, protocol);
397 if (r < 0) bb_perror_msg_and_die("socket");
402 // Die with an error message if we can't bind a socket to an address.
403 void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen)
405 if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind");
408 // Die with an error message if we can't listen for connections on a socket.
409 void xlisten(int s, int backlog)
411 if (listen(s, backlog)) bb_perror_msg_and_die("listen");
414 // xstat() - a stat() which dies on failure with meaningful error message
415 void xstat(char *name, struct stat *stat_buf)
417 if (stat(name, stat_buf))
418 bb_perror_msg_and_die("can't stat '%s'", name);
421 /* It is perfectly ok to pass in a NULL for either width or for
422 * height, in which case that value will not be set. */
423 int get_terminal_width_height(int fd, int *width, int *height)
425 struct winsize win = { 0, 0, 0, 0 };
426 int ret = ioctl(fd, TIOCGWINSZ, &win);
430 char *s = getenv("LINES");
431 if (s) win.ws_row = atoi(s);
433 if (win.ws_row <= 1 || win.ws_row >= 30000)
435 *height = (int) win.ws_row;
440 char *s = getenv("COLUMNS");
441 if (s) win.ws_col = atoi(s);
443 if (win.ws_col <= 1 || win.ws_col >= 30000)
445 *width = (int) win.ws_col;