1 /* vi: set sw=4 ts=4: */
3 * Mini dd implementation for busybox
6 * Copyright (C) 2000,2001 Matt Kraai
8 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
11 #include <signal.h> /* For FEATURE_DD_SIGNAL_HANDLING */
14 /* This is a NOEXEC applet. Be very careful! */
17 static const struct suffix_mult dd_suffixes[] = {
23 { "K", 1024 }, /* compat with coreutils dd */
32 off_t out_full, out_part, in_full, in_part;
34 #define G (*(struct globals*)&bb_common_bufsiz1)
36 static void dd_output_status(int ATTRIBUTE_UNUSED cur_signal)
38 fprintf(stderr, "%"OFF_FMT"d+%"OFF_FMT"d records in\n"
39 "%"OFF_FMT"d+%"OFF_FMT"d records out\n",
41 G.out_full, G.out_part);
44 static ssize_t full_write_or_warn(int fd, const void *buf, size_t len,
45 const char * const filename)
47 ssize_t n = full_write(fd, buf, len);
49 bb_perror_msg("writing '%s'", filename);
53 static bool write_and_stats(int fd, const void *buf, size_t len, size_t obs,
54 const char * const filename)
56 ssize_t n = full_write_or_warn(fd, buf, len, filename);
67 #define XATOU_SFX xatoull_sfx
69 #define XATOU_SFX xatoul_sfx
72 int dd_main(int argc, char **argv);
73 int dd_main(int argc, char **argv)
79 TWOBUFS_FLAG = 1 << 3,
81 static const char * const keywords[] = {
82 "bs=", "count=", "seek=", "skip=", "if=", "of=",
83 #if ENABLE_FEATURE_DD_IBS_OBS
84 "ibs=", "obs=", "conv=", "notrunc", "sync", "noerror",
95 #if ENABLE_FEATURE_DD_IBS_OBS
104 int flags = TRUNC_FLAG;
105 size_t oc = 0, ibs = 512, obs = 512;
107 off_t seek = 0, skip = 0, count = OFF_T_MAX;
109 const char *infile = NULL, *outfile = NULL;
112 memset(&G, 0, sizeof(G)); /* because of NOEXEC */
114 if (ENABLE_FEATURE_DD_SIGNAL_HANDLING) {
117 memset(&sa, 0, sizeof(sa));
118 sa.sa_handler = dd_output_status;
119 sa.sa_flags = SA_RESTART;
120 sigemptyset(&sa.sa_mask);
121 sigaction(SIGUSR1, &sa, 0);
124 for (n = 1; n < argc; n++) {
130 //XXX:FIXME: we reject plain "dd --" This would cost ~20 bytes, so..
131 //if (*arg == '-' && *++arg == '-' && !*++arg) continue;
132 key = strstr(arg, "=");
135 key_len = key - arg + 1;
136 key = xstrndup(arg, key_len);
137 what = index_in_str_array(keywords, key) + 1;
138 if (ENABLE_FEATURE_CLEAN_UP)
143 /* Must fit into positive ssize_t */
144 #if ENABLE_FEATURE_DD_IBS_OBS
145 if (what == OP_ibs) {
146 ibs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
149 if (what == OP_obs) {
150 obs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
153 if (what == OP_conv) {
155 /* find ',', replace them with nil so we can use arg for
156 * index_in_str_array without copying.
157 * We rely on arg being non-null, else strchr would fault.
159 key = strchr(arg, ',');
162 what = index_in_str_array(keywords, arg) + 1;
163 if (what < OP_conv_notrunc)
164 bb_error_msg_and_die(bb_msg_invalid_arg, arg, "conv");
165 if (what == OP_conv_notrunc)
166 flags &= ~TRUNC_FLAG;
167 if (what == OP_conv_sync)
169 if (what == OP_conv_noerror)
171 if (!key) /* no ',' left, so this was the last specifier */
173 arg = key + 1; /* skip this keyword and ',' */
179 ibs = obs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
182 /* These can be large: */
183 if (what == OP_count) {
184 count = XATOU_SFX(arg, dd_suffixes);
187 if (what == OP_seek) {
188 seek = XATOU_SFX(arg, dd_suffixes);
191 if (what == OP_skip) {
192 skip = XATOU_SFX(arg, dd_suffixes);
202 //XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
203 ibuf = obuf = xmalloc(ibs);
205 flags |= TWOBUFS_FLAG;
209 ifd = xopen(infile, O_RDONLY);
212 infile = bb_msg_standard_input;
214 if (outfile != NULL) {
215 int oflag = O_WRONLY | O_CREAT;
217 if (!seek && (flags & TRUNC_FLAG))
220 ofd = xopen(outfile, oflag);
222 if (seek && (flags & TRUNC_FLAG)) {
223 if (ftruncate(ofd, seek * obs) < 0) {
226 if (fstat(ofd, &st) < 0 || S_ISREG(st.st_mode) ||
233 outfile = bb_msg_standard_output;
236 if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
238 n = safe_read(ifd, ibuf, ibs);
247 if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
251 while (G.in_full + G.in_part != count) {
252 if (flags & NOERROR) /* Pre-zero the buffer when for NOERROR */
253 memset(ibuf, '\0', ibs);
254 n = safe_read(ifd, ibuf, ibs);
258 if (flags & NOERROR) {
260 bb_perror_msg("%s", infile);
264 if ((size_t)n == ibs)
268 if (flags & SYNC_FLAG) {
269 memset(ibuf + n, '\0', ibs - n);
273 if (flags & TWOBUFS_FLAG) {
280 memcpy(obuf + oc, tmp, d);
285 if (write_and_stats(ofd, obuf, obs, obs, outfile))
290 } else if (write_and_stats(ofd, ibuf, n, obs, outfile))
294 if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
295 w = full_write_or_warn(ofd, obuf, oc, outfile);
296 if (w < 0) goto out_status;
300 if (close(ifd) < 0) {
302 bb_perror_msg_and_die("%s", infile);
305 if (close(ofd) < 0) {
307 bb_perror_msg_and_die("%s", outfile);