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, 0777);
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 read the entire buffer.
114 void xread(int fd, void *buf, size_t count)
117 ssize_t size = full_read(fd, buf, count);
119 bb_error_msg_and_die("short read");
123 // Die with an error message if we can't write the entire buffer.
124 void xwrite(int fd, void *buf, size_t count)
127 ssize_t size = full_write(fd, buf, count);
129 bb_error_msg_and_die("short write");
133 // Die with an error message if we can't lseek to the right spot.
134 void xlseek(int fd, off_t offset, int whence)
136 if (offset != lseek(fd, offset, whence))
137 bb_error_msg_and_die("lseek");
140 // Die with an error message if we can't read one character.
141 unsigned char xread_char(int fd)
150 // Die with supplied error message if this FILE * has ferror set.
151 void xferror(FILE *fp, const char *fn)
154 bb_error_msg_and_die("%s", fn);
158 // Die with an error message if stdout has ferror set.
159 void xferror_stdout(void)
161 xferror(stdout, bb_msg_standard_output);
164 // Die with an error message if we have trouble flushing stdout.
165 void xfflush_stdout(void)
167 if (fflush(stdout)) {
168 bb_perror_msg_and_die(bb_msg_standard_output);
172 // This does a fork/exec in one call, using vfork(). Return PID of new child,
173 // -1 for failure. Runs argv[0], searching path if that has no / in it.
174 pid_t spawn(char **argv)
178 void *app = ENABLE_FEATURE_SH_STANDALONE_SHELL ? find_applet_by_name(argv[0]) : 0;
180 // Be nice to nommu machines.
183 if (pid < 0) return pid;
185 execvp(app ? CONFIG_BUSYBOX_EXEC_PATH : *argv, argv);
187 // We're sharing a stack with blocked parent, let parent know we failed
188 // and then exit to unblock parent (but don't run atexit() stuff, which
189 // would screw up parent.)
194 return failed ? failed : pid;
197 // Die with an error message if we can't spawn a child process.
198 pid_t xspawn(char **argv)
200 pid_t pid = spawn(argv);
201 if (pid < 0) bb_perror_msg_and_die("%s", *argv);
205 // Wait for the specified child PID to exit, returning child's error return.
206 int wait4pid(int pid)
210 if (pid == -1 || waitpid(pid, &status, 0) == -1) return -1;
211 if (WIFEXITED(status)) return WEXITSTATUS(status);
212 if (WIFSIGNALED(status)) return WTERMSIG(status);
216 void xsetenv(const char *key, const char *value)
218 if (setenv(key, value, 1))
219 bb_error_msg_and_die(bb_msg_memory_exhausted);
222 // Convert unsigned integer to ascii, writing into supplied buffer. A
223 // truncated result is always null terminated (unless buflen is 0), and
224 // contains the first few digits of the result ala strncpy.
225 void utoa_to_buf(unsigned n, char *buf, unsigned buflen)
229 for (i=1000000000; i; i/=10) {
232 if ((res || out || i == 1) && --buflen>0) {
242 // Convert signed integer to ascii, like utoa_to_buf()
243 void itoa_to_buf(int n, char *buf, unsigned buflen)
250 utoa_to_buf((unsigned)n, buf, buflen);
253 // The following two functions use a static buffer, so calling either one a
254 // second time will overwrite previous results.
256 // The largest 32 bit integer is -2 billion plus null terminator, or 12 bytes.
257 // Int should always be 32 bits on any remotely Unix-like system, see
258 // http://www.unix.org/whitepapers/64bit.html for the reasons why.
260 static char local_buf[12];
262 // Convert unsigned integer to ascii using a static buffer (returned).
263 char *utoa(unsigned n)
265 utoa_to_buf(n, local_buf, sizeof(local_buf));
270 // Convert signed integer to ascii using a static buffer (returned).
273 itoa_to_buf(n, local_buf, sizeof(local_buf));
278 // Die with an error message if we can't set gid. (Because resource limits may
279 // limit this user to a given number of processes, and if that fills up the
280 // setgid() will fail and we'll _still_be_root_, which is bad.)
281 void xsetgid(gid_t gid)
283 if (setgid(gid)) bb_error_msg_and_die("setgid");
286 // Die with an error message if we cant' set uid. (See xsetgid() for why.)
287 void xsetuid(uid_t uid)
289 if (setuid(uid)) bb_error_msg_and_die("setuid");
292 // Return how long the file at fd is, if there's any way to determine it.
293 off_t fdlength(int fd)
295 off_t bottom = 0, top = 0, pos;
298 // If the ioctl works for this, return it.
300 if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
302 // If not, do a binary search for the last location we can read. (Some
303 // block devices don't do BLKGETSIZE right.)
308 pos = bottom + (top - bottom) / 2;
310 // If we can read from the current location, it's bigger.
312 if (lseek(fd, pos, 0)>=0 && safe_read(fd, &temp, 1)==1) {
313 if (bottom == top) bottom = top = (top+1) * 2;
316 // If we can't, it's smaller.
325 } while (bottom + 1 != top);
330 // Die with an error message if we can't malloc() enough space and do an
331 // sprintf() into that space.
332 char *xasprintf(const char *format, ...)
341 r = vasprintf(&string_ptr, format, p);
344 // Bloat for systems that haven't got the GNU extension.
346 r = vsnprintf(NULL, 0, format, p);
348 string_ptr = xmalloc(r+1);
350 r = vsnprintf(string_ptr, r+1, format, p);
354 if (r < 0) bb_error_msg_and_die(bb_msg_memory_exhausted);
358 // Die with an error message if we can't copy an entire FILE * to stdout, then
360 void xprint_and_close_file(FILE *file)
362 // copyfd outputs error messages for us.
363 if (bb_copyfd_eof(fileno(file), 1) == -1)
364 exit(xfunc_error_retval);
369 // Die if we can't chdir to a new path.
370 void xchdir(const char *path)
373 bb_perror_msg_and_die("chdir(%s)", path);
376 // Print a warning message if opendir() fails, but don't die.
377 DIR *warn_opendir(const char *path)
381 if ((dp = opendir(path)) == NULL) {
382 bb_perror_msg("unable to open `%s'", path);
388 // Die with an error message if opendir() fails.
389 DIR *xopendir(const char *path)
393 if ((dp = opendir(path)) == NULL)
394 bb_perror_msg_and_die("unable to open `%s'", path);
399 // Die with an error message if we can't daemonize.
400 void xdaemon(int nochdir, int noclose)
402 if (daemon(nochdir, noclose)) bb_perror_msg_and_die("daemon");
406 // Die with an error message if we can't open a new socket.
407 int xsocket(int domain, int type, int protocol)
409 int r = socket(domain, type, protocol);
411 if (r < 0) bb_perror_msg_and_die("socket");
416 // Die with an error message if we can't bind a socket to an address.
417 void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen)
419 if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind");
422 // Die with an error message if we can't listen for connections on a socket.
423 void xlisten(int s, int backlog)
425 if (listen(s, backlog)) bb_perror_msg_and_die("listen");
428 // xstat() - a stat() which dies on failure with meaningful error message
429 void xstat(char *name, struct stat *stat_buf)
431 if (stat(name, stat_buf))
432 bb_perror_msg_and_die("can't stat '%s'", name);
435 /* It is perfectly ok to pass in a NULL for either width or for
436 * * height, in which case that value will not be set. */
437 int get_terminal_width_height(int fd, int *width, int *height)
439 struct winsize win = { 0, 0, 0, 0 };
440 int ret = ioctl(fd, TIOCGWINSZ, &win);
442 char *s = getenv("LINES");
443 if (s) win.ws_row = atoi(s);
445 if (win.ws_row <= 1) win.ws_row = 24;
447 char *s = getenv("COLUMNS");
448 if (s) win.ws_col = atoi(s);
450 if (win.ws_col <= 1) win.ws_col = 80;
451 if (height) *height = (int) win.ws_row;
452 if (width) *width = (int) win.ws_col;