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
20 // Die if we can't allocate size bytes of memory.
21 void *xmalloc(size_t size)
23 void *ptr = malloc(size);
24 if (ptr == NULL && size != 0)
25 bb_error_msg_and_die(bb_msg_memory_exhausted);
31 // Die if we can't resize previously allocated memory. (This returns a pointer
32 // to the new memory, which may or may not be the same as the old memory.
33 // It'll copy the contents to a new chunk and free the old one if necessary.)
34 void *xrealloc(void *ptr, size_t size)
36 ptr = realloc(ptr, size);
37 if (ptr == NULL && size != 0)
38 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);
56 // Die if we can't copy a string to freshly allocated memory.
57 char * xstrdup(const char *s)
67 bb_error_msg_and_die(bb_msg_memory_exhausted);
74 // Die if we can't allocate n+1 bytes (space for the null terminator) and copy
75 // the (possibly truncated to length n) string into it.
76 char * xstrndup(const char *s, int n)
80 if (ENABLE_DEBUG && s == NULL)
81 bb_error_msg_and_die("xstrndup bug");
85 return safe_strncpy(t,s,n);
90 // Die if we can't open a file and return a FILE * to it.
91 // Notice we haven't got xfread(), This is for use with fscanf() and friends.
92 FILE *xfopen(const char *path, const char *mode)
95 if ((fp = fopen(path, mode)) == NULL)
96 bb_perror_msg_and_die("%s", path);
102 // Die if we can't open an existing file and return an fd.
103 int xopen(const char *pathname, int flags)
105 if (ENABLE_DEBUG && (flags && O_CREAT))
106 bb_error_msg_and_die("xopen() with O_CREAT\n");
108 return xopen3(pathname, flags, 0777);
113 // Die if we can't open a new file and return an fd.
114 int xopen3(const char *pathname, int flags, int mode)
118 ret = open(pathname, flags, mode);
120 bb_perror_msg_and_die("%s", pathname);
127 // Die with an error message if we can't read the entire buffer.
128 void xread(int fd, void *buf, size_t count)
133 if ((size = safe_read(fd, buf, count)) < 1)
134 bb_error_msg_and_die("Short read");
136 buf = ((char *) buf) + size;
142 // Die with an error message if we can't write the entire buffer.
143 void xwrite(int fd, void *buf, size_t count)
148 if ((size = safe_write(fd, buf, count)) < 1)
149 bb_error_msg_and_die("Short write");
151 buf = ((char *) buf) + size;
157 // Die with an error message if we can't lseek to the right spot.
158 void xlseek(int fd, off_t offset, int whence)
160 if (offset != lseek(fd, offset, whence)) bb_error_msg_and_die("lseek");
165 // Die with an error message if we can't read one character.
166 unsigned char xread_char(int fd)
177 // Die with supplied error message if this FILE * has ferror set.
178 void xferror(FILE *fp, const char *fn)
181 bb_error_msg_and_die("%s", fn);
186 #ifdef L_xferror_stdout
187 // Die with an error message if stdout has ferror set.
188 void xferror_stdout(void)
190 xferror(stdout, bb_msg_standard_output);
194 #ifdef L_xfflush_stdout
195 // Die with an error message if we have trouble flushing stdout.
196 void xfflush_stdout(void)
198 if (fflush(stdout)) {
199 bb_perror_msg_and_die(bb_msg_standard_output);
205 // This does a fork/exec in one call, using vfork(). Return PID of new child,
206 // -1 for failure. Runs argv[0], searching path if that has no / in it.
207 pid_t spawn(char **argv)
211 void *app = find_applet_by_name(argv[0]);
213 // Be nice to nommu machines.
216 if (pid < 0) return pid;
218 execvp(app ? CONFIG_BUSYBOX_EXEC_PATH : *argv, argv);
220 // We're sharing a stack with blocked parent, let parent know we failed
221 // and then exit to unblock parent (but don't run atexit() stuff, which
222 // would screw up parent.)
227 return failed ? failed : pid;
232 // Die with an error message if we can't spawn a child process.
233 pid_t xspawn(char **argv)
235 pid_t pid = spawn(argv);
236 if (pid < 0) bb_perror_msg_and_die("%s", *argv);
242 // Wait for the specified child PID to exit, returning child's error return.
243 int wait4pid(int pid)
247 if (pid == -1 || waitpid(pid, &status, 0) == -1) return -1;
248 if (WIFEXITED(status)) return WEXITSTATUS(status);
249 if (WIFSIGNALED(status)) return WTERMSIG(status);
255 // Convert unsigned integer to ascii, writing into supplied buffer. A
256 // truncated result is always null terminated (unless buflen is 0), and
257 // contains the first few digits of the result ala strncpy.
258 void utoa_to_buf(unsigned n, char *buf, unsigned buflen)
262 for (i=1000000000; i; i/=10) {
265 if ((res || out || i == 1) && --buflen>0) {
275 // Convert signed integer to ascii, like utoa_to_buf()
276 void itoa_to_buf(int n, char *buf, unsigned buflen)
283 utoa_to_buf((unsigned)n, buf, buflen);
286 // The following two functions use a static buffer, so calling either one a
287 // second time will overwrite previous results.
289 // The largest 32 bit integer is -2 billion plus null terminator, or 12 bytes.
290 // Int should always be 32 bits on any remotely Unix-like system, see
291 // http://www.unix.org/whitepapers/64bit.html for the reasons why.
293 static char local_buf[12];
295 // Convert unsigned integer to ascii using a static buffer (returned).
296 char *utoa(unsigned n)
298 utoa_to_buf(n, local_buf, sizeof(local_buf));
303 // Convert signed integer to ascii using a static buffer (returned).
306 itoa_to_buf(n, local_buf, sizeof(local_buf));
313 // Die with an error message if we can't set gid. (Because resource limits may
314 // limit this user to a given number of processes, and if that fills up the
315 // setgid() will fail and we'll _still_be_root_, which is bad.)
316 void xsetgid(gid_t gid)
318 if (setgid(gid)) bb_error_msg_and_die("setgid");
321 // Die with an error message if we cant' set uid. (See xsetgid() for why.)
322 void xsetuid(uid_t uid)
324 if (setuid(uid)) bb_error_msg_and_die("setuid");
329 // Return how long the file at fd is, if there's any way to determine it.
330 off_t fdlength(int fd)
332 off_t bottom = 0, top = 0, pos;
335 // If the ioctl works for this, return it.
337 if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512;
339 // If not, do a binary search for the last location we can read. (Some
340 // block devices don't do BLKGETSIZE right.)
345 pos = bottom + (top - bottom) / 2;;
347 // If we can read from the current location, it's bigger.
349 if (lseek(fd, pos, 0)>=0 && safe_read(fd, &temp, 1)==1) {
350 if (bottom == top) bottom = top = (top+1) * 2;
353 // If we can't, it's smaller.
362 } while (bottom + 1 != top);
369 // Die with an error message if we can't malloc() enough space and do an
370 // sprintf() into that space.
371 char *xasprintf(const char *format, ...)
380 r = vasprintf(&string_ptr, format, p);
383 // Bloat for systems that haven't got the GNU extension.
385 r = vsnprintf(NULL, 0, format, p);
387 string_ptr = xmalloc(r+1);
389 r = vsnprintf(string_ptr, r+1, format, p);
393 if (r < 0) bb_perror_msg_and_die("xasprintf");
398 #ifdef L_xprint_and_close_file
399 // Die with an error message if we can't copy an entire FILE * to stdout, then
401 void xprint_and_close_file(FILE *file)
403 // copyfd outputs error messages for us.
404 if (bb_copyfd_eof(fileno(file), 1) == -1) exit(bb_default_error_retval);
411 // Die if we can't chdir to a new path.
412 void xchdir(const char *path)
415 bb_perror_msg_and_die("chdir(%s)", path);
419 #ifdef L_warn_opendir
420 // Print a warning message if opendir() fails, but don't die.
421 DIR *warn_opendir(const char *path)
425 if ((dp = opendir(path)) == NULL) {
426 bb_perror_msg("unable to open `%s'", path);
434 // Die with an error message if opendir() fails.
435 DIR *xopendir(const char *path)
439 if ((dp = opendir(path)) == NULL)
440 bb_perror_msg_and_die("unable to open `%s'", path);
447 // Die with an error message if we can't daemonize.
448 void xdaemon(int nochdir, int noclose)
450 if (daemon(nochdir, noclose)) bb_perror_msg_and_die("daemon");
456 // Die with an error message if we can't open a new socket.
457 int xsocket(int domain, int type, int protocol)
459 int r = socket(domain, type, protocol);
461 if (r < 0) bb_perror_msg_and_die("socket");
468 // Die with an error message if we can't bind a socket to an address.
469 void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen)
471 if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind");
476 // Die with an error message if we can't listen for connections on a socket.
477 void xlisten(int s, int backlog)
479 if (listen(s, backlog)) bb_perror_msg_and_die("listen");