| /* vi: set sw=4 ts=4: */ |
| /* |
| * Utility routines. |
| * |
| * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> |
| * Copyright (C) 2006 Rob Landley |
| * Copyright (C) 2006 Denis Vlasenko |
| * |
| * Licensed under GPL version 2, see file LICENSE in this tarball for details. |
| */ |
| |
| #include "busybox.h" |
| |
| /* All the functions starting with "x" call bb_error_msg_and_die() if they |
| * fail, so callers never need to check for errors. If it returned, it |
| * succeeded. */ |
| |
| #ifndef DMALLOC |
| /* dmalloc provides variants of these that do abort() on failure. |
| * Since dmalloc's prototypes overwrite the impls here as they are |
| * included after these prototypes in libbb.h, all is well. |
| */ |
| // Die if we can't allocate size bytes of memory. |
| void *xmalloc(size_t size) |
| { |
| void *ptr = malloc(size); |
| if (ptr == NULL && size != 0) |
| bb_error_msg_and_die(bb_msg_memory_exhausted); |
| return ptr; |
| } |
| |
| // Die if we can't resize previously allocated memory. (This returns a pointer |
| // to the new memory, which may or may not be the same as the old memory. |
| // It'll copy the contents to a new chunk and free the old one if necessary.) |
| void *xrealloc(void *ptr, size_t size) |
| { |
| ptr = realloc(ptr, size); |
| if (ptr == NULL && size != 0) |
| bb_error_msg_and_die(bb_msg_memory_exhausted); |
| return ptr; |
| } |
| #endif /* DMALLOC */ |
| |
| // Die if we can't allocate and zero size bytes of memory. |
| void *xzalloc(size_t size) |
| { |
| void *ptr = xmalloc(size); |
| memset(ptr, 0, size); |
| return ptr; |
| } |
| |
| // Die if we can't copy a string to freshly allocated memory. |
| char * xstrdup(const char *s) |
| { |
| char *t; |
| |
| if (s == NULL) |
| return NULL; |
| |
| t = strdup (s); |
| |
| if (t == NULL) |
| bb_error_msg_and_die(bb_msg_memory_exhausted); |
| |
| return t; |
| } |
| |
| // Die if we can't allocate n+1 bytes (space for the null terminator) and copy |
| // the (possibly truncated to length n) string into it. |
| char * xstrndup(const char *s, int n) |
| { |
| char *t; |
| |
| if (ENABLE_DEBUG && s == NULL) |
| bb_error_msg_and_die("xstrndup bug"); |
| |
| t = xmalloc(++n); |
| |
| return safe_strncpy(t,s,n); |
| } |
| |
| // Die if we can't open a file and return a FILE * to it. |
| // Notice we haven't got xfread(), This is for use with fscanf() and friends. |
| FILE *xfopen(const char *path, const char *mode) |
| { |
| FILE *fp; |
| if ((fp = fopen(path, mode)) == NULL) |
| bb_perror_msg_and_die("%s", path); |
| return fp; |
| } |
| |
| // Die if we can't open an existing file and return an fd. |
| int xopen(const char *pathname, int flags) |
| { |
| if (ENABLE_DEBUG && (flags & O_CREAT)) |
| bb_error_msg_and_die("xopen() with O_CREAT"); |
| |
| return xopen3(pathname, flags, 0666); |
| } |
| |
| // Die if we can't open a new file and return an fd. |
| int xopen3(const char *pathname, int flags, int mode) |
| { |
| int ret; |
| |
| ret = open(pathname, flags, mode); |
| if (ret < 0) { |
| bb_perror_msg_and_die("%s", pathname); |
| } |
| return ret; |
| } |
| |
| // Die with an error message if we can't write the entire buffer. |
| void xwrite(int fd, void *buf, size_t count) |
| { |
| if (count) { |
| ssize_t size = full_write(fd, buf, count); |
| if (size != count) |
| bb_error_msg_and_die("short write"); |
| } |
| } |
| |
| // Die with an error message if we can't lseek to the right spot. |
| off_t xlseek(int fd, off_t offset, int whence) |
| { |
| off_t off = lseek(fd, offset, whence); |
| if (off == (off_t)-1) |
| bb_perror_msg_and_die("lseek"); |
| return off; |
| } |
| |
| // Die with supplied error message if this FILE * has ferror set. |
| void xferror(FILE *fp, const char *fn) |
| { |
| if (ferror(fp)) { |
| bb_error_msg_and_die("%s", fn); |
| } |
| } |
| |
| // Die with an error message if stdout has ferror set. |
| void xferror_stdout(void) |
| { |
| xferror(stdout, bb_msg_standard_output); |
| } |
| |
| // Die with an error message if we have trouble flushing stdout. |
| void xfflush_stdout(void) |
| { |
| if (fflush(stdout)) { |
| bb_perror_msg_and_die(bb_msg_standard_output); |
| } |
| } |
| |
| // This does a fork/exec in one call, using vfork(). Return PID of new child, |
| // -1 for failure. Runs argv[0], searching path if that has no / in it. |
| pid_t spawn(char **argv) |
| { |
| static int failed; |
| pid_t pid; |
| void *app = ENABLE_FEATURE_SH_STANDALONE_SHELL ? find_applet_by_name(argv[0]) : 0; |
| |
| // Be nice to nommu machines. |
| failed = 0; |
| pid = vfork(); |
| if (pid < 0) return pid; |
| if (!pid) { |
| execvp(app ? CONFIG_BUSYBOX_EXEC_PATH : *argv, argv); |
| |
| // We're sharing a stack with blocked parent, let parent know we failed |
| // and then exit to unblock parent (but don't run atexit() stuff, which |
| // would screw up parent.) |
| |
| failed = -1; |
| _exit(0); |
| } |
| return failed ? failed : pid; |
| } |
| |
| // Die with an error message if we can't spawn a child process. |
| pid_t xspawn(char **argv) |
| { |
| pid_t pid = spawn(argv); |
| if (pid < 0) bb_perror_msg_and_die("%s", *argv); |
| return pid; |
| } |
| |
| // Wait for the specified child PID to exit, returning child's error return. |
| int wait4pid(int pid) |
| { |
| int status; |
| |
| if (pid == -1 || waitpid(pid, &status, 0) == -1) return -1; |
| if (WIFEXITED(status)) return WEXITSTATUS(status); |
| if (WIFSIGNALED(status)) return WTERMSIG(status); |
| return 0; |
| } |
| |
| void xsetenv(const char *key, const char *value) |
| { |
| if (setenv(key, value, 1)) |
| bb_error_msg_and_die(bb_msg_memory_exhausted); |
| } |
| |
| // Convert unsigned integer to ascii, writing into supplied buffer. A |
| // truncated result is always null terminated (unless buflen is 0), and |
| // contains the first few digits of the result ala strncpy. |
| void utoa_to_buf(unsigned n, char *buf, unsigned buflen) |
| { |
| int i, out = 0; |
| if (buflen) { |
| for (i=1000000000; i; i/=10) { |
| int res = n/i; |
| |
| if ((res || out || i == 1) && --buflen>0) { |
| out++; |
| n -= res*i; |
| *buf++ = '0' + res; |
| } |
| } |
| *buf = 0; |
| } |
| } |
| |
| // Convert signed integer to ascii, like utoa_to_buf() |
| void itoa_to_buf(int n, char *buf, unsigned buflen) |
| { |
| if (buflen && n<0) { |
| n = -n; |
| *buf++ = '-'; |
| buflen--; |
| } |
| utoa_to_buf((unsigned)n, buf, buflen); |
| } |
| |
| // The following two functions use a static buffer, so calling either one a |
| // second time will overwrite previous results. |
| // |
| // The largest 32 bit integer is -2 billion plus null terminator, or 12 bytes. |
| // Int should always be 32 bits on any remotely Unix-like system, see |
| // http://www.unix.org/whitepapers/64bit.html for the reasons why. |
| |
| static char local_buf[12]; |
| |
| // Convert unsigned integer to ascii using a static buffer (returned). |
| char *utoa(unsigned n) |
| { |
| utoa_to_buf(n, local_buf, sizeof(local_buf)); |
| |
| return local_buf; |
| } |
| |
| // Convert signed integer to ascii using a static buffer (returned). |
| char *itoa(int n) |
| { |
| itoa_to_buf(n, local_buf, sizeof(local_buf)); |
| |
| return local_buf; |
| } |
| |
| // Die with an error message if we can't set gid. (Because resource limits may |
| // limit this user to a given number of processes, and if that fills up the |
| // setgid() will fail and we'll _still_be_root_, which is bad.) |
| void xsetgid(gid_t gid) |
| { |
| if (setgid(gid)) bb_error_msg_and_die("setgid"); |
| } |
| |
| // Die with an error message if we cant' set uid. (See xsetgid() for why.) |
| void xsetuid(uid_t uid) |
| { |
| if (setuid(uid)) bb_error_msg_and_die("setuid"); |
| } |
| |
| // Return how long the file at fd is, if there's any way to determine it. |
| off_t fdlength(int fd) |
| { |
| off_t bottom = 0, top = 0, pos; |
| long size; |
| |
| // If the ioctl works for this, return it. |
| |
| if (ioctl(fd, BLKGETSIZE, &size) >= 0) return size*512; |
| |
| // If not, do a binary search for the last location we can read. (Some |
| // block devices don't do BLKGETSIZE right.) |
| |
| do { |
| char temp; |
| |
| pos = bottom + (top - bottom) / 2; |
| |
| // If we can read from the current location, it's bigger. |
| |
| if (lseek(fd, pos, SEEK_SET)>=0 && safe_read(fd, &temp, 1)==1) { |
| if (bottom == top) bottom = top = (top+1) * 2; |
| else bottom = pos; |
| |
| // If we can't, it's smaller. |
| |
| } else { |
| if (bottom == top) { |
| if (!top) return 0; |
| bottom = top/2; |
| } |
| else top = pos; |
| } |
| } while (bottom + 1 != top); |
| |
| return pos + 1; |
| } |
| |
| // Die with an error message if we can't malloc() enough space and do an |
| // sprintf() into that space. |
| char *xasprintf(const char *format, ...) |
| { |
| va_list p; |
| int r; |
| char *string_ptr; |
| |
| #if 1 |
| // GNU extension |
| va_start(p, format); |
| r = vasprintf(&string_ptr, format, p); |
| va_end(p); |
| #else |
| // Bloat for systems that haven't got the GNU extension. |
| va_start(p, format); |
| r = vsnprintf(NULL, 0, format, p); |
| va_end(p); |
| string_ptr = xmalloc(r+1); |
| va_start(p, format); |
| r = vsnprintf(string_ptr, r+1, format, p); |
| va_end(p); |
| #endif |
| |
| if (r < 0) bb_error_msg_and_die(bb_msg_memory_exhausted); |
| return string_ptr; |
| } |
| |
| // Die with an error message if we can't copy an entire FILE * to stdout, then |
| // close that file. |
| void xprint_and_close_file(FILE *file) |
| { |
| // copyfd outputs error messages for us. |
| if (bb_copyfd_eof(fileno(file), 1) == -1) |
| exit(xfunc_error_retval); |
| |
| fclose(file); |
| } |
| |
| // Die if we can't chdir to a new path. |
| void xchdir(const char *path) |
| { |
| if (chdir(path)) |
| bb_perror_msg_and_die("chdir(%s)", path); |
| } |
| |
| // Print a warning message if opendir() fails, but don't die. |
| DIR *warn_opendir(const char *path) |
| { |
| DIR *dp; |
| |
| if ((dp = opendir(path)) == NULL) { |
| bb_perror_msg("unable to open `%s'", path); |
| return NULL; |
| } |
| return dp; |
| } |
| |
| // Die with an error message if opendir() fails. |
| DIR *xopendir(const char *path) |
| { |
| DIR *dp; |
| |
| if ((dp = opendir(path)) == NULL) |
| bb_perror_msg_and_die("unable to open `%s'", path); |
| return dp; |
| } |
| |
| #ifndef BB_NOMMU |
| // Die with an error message if we can't daemonize. |
| void xdaemon(int nochdir, int noclose) |
| { |
| if (daemon(nochdir, noclose)) bb_perror_msg_and_die("daemon"); |
| } |
| #endif |
| |
| // Die with an error message if we can't open a new socket. |
| int xsocket(int domain, int type, int protocol) |
| { |
| int r = socket(domain, type, protocol); |
| |
| if (r < 0) bb_perror_msg_and_die("socket"); |
| |
| return r; |
| } |
| |
| // Die with an error message if we can't bind a socket to an address. |
| void xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen) |
| { |
| if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind"); |
| } |
| |
| // Die with an error message if we can't listen for connections on a socket. |
| void xlisten(int s, int backlog) |
| { |
| if (listen(s, backlog)) bb_perror_msg_and_die("listen"); |
| } |
| |
| // xstat() - a stat() which dies on failure with meaningful error message |
| void xstat(char *name, struct stat *stat_buf) |
| { |
| if (stat(name, stat_buf)) |
| bb_perror_msg_and_die("can't stat '%s'", name); |
| } |
| |
| /* It is perfectly ok to pass in a NULL for either width or for |
| * * height, in which case that value will not be set. */ |
| int get_terminal_width_height(int fd, int *width, int *height) |
| { |
| struct winsize win = { 0, 0, 0, 0 }; |
| int ret = ioctl(fd, TIOCGWINSZ, &win); |
| if (!win.ws_row) { |
| char *s = getenv("LINES"); |
| if (s) win.ws_row = atoi(s); |
| } |
| if (win.ws_row <= 1) win.ws_row = 24; |
| if (!win.ws_col) { |
| char *s = getenv("COLUMNS"); |
| if (s) win.ws_col = atoi(s); |
| } |
| if (win.ws_col <= 1) win.ws_col = 80; |
| if (height) *height = (int) win.ws_row; |
| if (width) *width = (int) win.ws_col; |
| |
| return ret; |
| } |