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 source tree.
11 //usage:#define dd_trivial_usage
12 //usage: "[if=FILE] [of=FILE] " IF_FEATURE_DD_IBS_OBS("[ibs=N] [obs=N] ") "[bs=N] [count=N] [skip=N]\n"
13 //usage: " [seek=N]" IF_FEATURE_DD_IBS_OBS(" [conv=notrunc|noerror|sync|fsync]")
14 //usage:#define dd_full_usage "\n\n"
15 //usage: "Copy a file with converting and formatting\n"
17 //usage: "\n if=FILE Read from FILE instead of stdin"
18 //usage: "\n of=FILE Write to FILE instead of stdout"
19 //usage: "\n bs=N Read and write N bytes at a time"
20 //usage: IF_FEATURE_DD_IBS_OBS(
21 //usage: "\n ibs=N Read N bytes at a time"
23 //usage: IF_FEATURE_DD_IBS_OBS(
24 //usage: "\n obs=N Write N bytes at a time"
26 //usage: "\n count=N Copy only N input blocks"
27 //usage: "\n skip=N Skip N input blocks"
28 //usage: "\n seek=N Skip N output blocks"
29 //usage: IF_FEATURE_DD_IBS_OBS(
30 //usage: "\n conv=notrunc Don't truncate output file"
31 //usage: "\n conv=noerror Continue after read errors"
32 //usage: "\n conv=sync Pad blocks with zeros"
33 //usage: "\n conv=fsync Physically write data out before finishing"
36 //usage: "\nNumbers may be suffixed by c (x1), w (x2), b (x512), kD (x1000), k (x1024),"
37 //usage: "\nMD (x1000000), M (x1048576), GD (x1000000000) or G (x1073741824)"
39 //usage:#define dd_example_usage
40 //usage: "$ dd if=/dev/zero of=/dev/ram1 bs=1M count=4\n"
41 //usage: "4+0 records in\n"
42 //usage: "4+0 records out\n"
46 /* This is a NOEXEC applet. Be very careful! */
54 static const struct suffix_mult dd_suffixes[] = {
60 { "K", 1024 }, /* compat with coreutils dd */
69 off_t out_full, out_part, in_full, in_part;
70 #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
71 unsigned long long total_bytes;
72 unsigned long long begin_time_us;
75 #define G (*(struct globals*)&bb_common_bufsiz1)
76 #define INIT_G() do { \
77 /* we have to zero it out because of NOEXEC */ \
78 memset(&G, 0, sizeof(G)); \
82 static void dd_output_status(int UNUSED_PARAM cur_signal)
84 #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
86 unsigned long long bytes_sec;
87 unsigned long long now_us = monotonic_us(); /* before fprintf */
90 /* Deliberately using %u, not %d */
91 fprintf(stderr, "%"OFF_FMT"u+%"OFF_FMT"u records in\n"
92 "%"OFF_FMT"u+%"OFF_FMT"u records out\n",
94 G.out_full, G.out_part);
96 #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
97 fprintf(stderr, "%llu bytes (%sB) copied, ",
99 /* show fractional digit, use suffixes */
100 make_human_readable_str(G.total_bytes, 1, 0)
103 * ./busybox dd </dev/null >/dev/null
104 * ./busybox dd bs=1M count=2000 </dev/zero >/dev/null
105 * (echo DONE) | ./busybox dd >/dev/null
106 * (sleep 1; echo DONE) | ./busybox dd >/dev/null
108 seconds = (now_us - G.begin_time_us) / 1000000.0;
109 bytes_sec = G.total_bytes / seconds;
110 fprintf(stderr, "%f seconds, %sB/s\n",
112 /* show fractional digit, use suffixes */
113 make_human_readable_str(bytes_sec, 1, 0)
118 static ssize_t full_write_or_warn(const void *buf, size_t len,
119 const char *const filename)
121 ssize_t n = full_write(ofd, buf, len);
123 bb_perror_msg("writing '%s'", filename);
127 static bool write_and_stats(const void *buf, size_t len, size_t obs,
128 const char *filename)
130 ssize_t n = full_write_or_warn(buf, len, filename);
133 if ((size_t)n == obs)
135 else if (n) /* > 0 */
137 #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
144 # define XATOU_SFX xatoull_sfx
146 # define XATOU_SFX xatoul_sfx
149 int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
150 int dd_main(int argc UNUSED_PARAM, char **argv)
153 /* Must be in the same order as OP_conv_XXX! */
154 /* (see "flags |= (1 << what)" below) */
155 FLAG_NOTRUNC = 1 << 0,
157 FLAG_NOERROR = 1 << 2,
159 /* end of conv flags */
160 FLAG_TWOBUFS = 1 << 4,
163 static const char keywords[] ALIGN1 =
164 "bs\0""count\0""seek\0""skip\0""if\0""of\0"
165 #if ENABLE_FEATURE_DD_IBS_OBS
166 "ibs\0""obs\0""conv\0"
169 #if ENABLE_FEATURE_DD_IBS_OBS
170 static const char conv_words[] ALIGN1 =
171 "notrunc\0""sync\0""noerror\0""fsync\0";
180 #if ENABLE_FEATURE_DD_IBS_OBS
184 /* Must be in the same order as FLAG_XXX! */
189 /* Unimplemented conv=XXX: */
190 //nocreat do not create the output file
191 //excl fail if the output file already exists
192 //fdatasync physically write output file data before finishing
193 //swab swap every pair of input bytes
194 //lcase change upper case to lower case
195 //ucase change lower case to upper case
196 //block pad newline-terminated records with spaces to cbs-size
197 //unblock replace trailing spaces in cbs-size records with newline
198 //ascii from EBCDIC to ASCII
199 //ebcdic from ASCII to EBCDIC
200 //ibm from ASCII to alternate EBCDIC
203 int exitcode = EXIT_FAILURE;
204 size_t ibs = 512, obs = 512;
207 /* And these are all zeroed at once! */
213 const char *infile, *outfile;
215 #define flags (Z.flags )
217 #define count (Z.count )
218 #define seek (Z.seek )
219 #define skip (Z.skip )
220 #define infile (Z.infile )
221 #define outfile (Z.outfile)
223 memset(&Z, 0, sizeof(Z));
225 //fflush_all(); - is this needed because of NOEXEC?
227 for (n = 1; argv[n]; n++) {
233 /* "dd --". NB: coreutils 6.9 will complain if they see
234 * more than one of them. We wouldn't. */
235 if (arg[0] == '-' && arg[1] == '-' && arg[2] == '\0')
238 val = strchr(arg, '=');
242 what = index_in_strings(keywords, arg);
245 /* *val = '='; - to preserve ps listing? */
247 #if ENABLE_FEATURE_DD_IBS_OBS
248 if (what == OP_ibs) {
249 /* Must fit into positive ssize_t */
250 ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
253 if (what == OP_obs) {
254 obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
257 if (what == OP_conv) {
259 /* find ',', replace them with NUL so we can use val for
260 * index_in_strings() without copying.
261 * We rely on val being non-null, else strchr would fault.
263 arg = strchr(val, ',');
266 what = index_in_strings(conv_words, val);
268 bb_error_msg_and_die(bb_msg_invalid_arg, val, "conv");
269 flags |= (1 << what);
270 if (!arg) /* no ',' left, so this was the last specifier */
272 /* *arg = ','; - to preserve ps listing? */
273 val = arg + 1; /* skip this keyword and ',' */
275 continue; /* we trashed 'what', can't fall through */
279 ibs = obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
282 /* These can be large: */
283 if (what == OP_count) {
285 count = XATOU_SFX(val, dd_suffixes);
288 if (what == OP_seek) {
289 seek = XATOU_SFX(val, dd_suffixes);
292 if (what == OP_skip) {
293 skip = XATOU_SFX(val, dd_suffixes);
304 } /* end of "for (argv[n])" */
306 //XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
307 ibuf = obuf = xmalloc(ibs);
309 flags |= FLAG_TWOBUFS;
313 #if ENABLE_FEATURE_DD_SIGNAL_HANDLING
314 signal_SA_RESTART_empty_mask(SIGUSR1, dd_output_status);
316 #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
317 G.begin_time_us = monotonic_us();
321 xmove_fd(xopen(infile, O_RDONLY), ifd);
323 infile = bb_msg_standard_input;
325 if (outfile != NULL) {
326 int oflag = O_WRONLY | O_CREAT;
328 if (!seek && !(flags & FLAG_NOTRUNC))
331 xmove_fd(xopen(outfile, oflag), ofd);
333 if (seek && !(flags & FLAG_NOTRUNC)) {
334 if (ftruncate(ofd, seek * obs) < 0) {
337 if (fstat(ofd, &st) < 0
338 || S_ISREG(st.st_mode)
339 || S_ISDIR(st.st_mode)
346 outfile = bb_msg_standard_output;
349 if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
351 n = safe_read(ifd, ibuf, ibs);
360 if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
364 while (!(flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
365 n = safe_read(ifd, ibuf, ibs);
370 if (!(flags & FLAG_NOERROR))
372 bb_simple_perror_msg(infile);
373 /* GNU dd with conv=noerror skips over bad blocks */
374 xlseek(ifd, ibs, SEEK_CUR);
375 /* conv=noerror,sync writes NULs,
376 * conv=noerror just ignores input bad blocks */
379 if ((size_t)n == ibs)
383 if (flags & FLAG_SYNC) {
384 memset(ibuf + n, 0, ibs - n);
388 if (flags & FLAG_TWOBUFS) {
395 memcpy(obuf + oc, tmp, d);
400 if (write_and_stats(obuf, obs, obs, outfile))
405 } else if (write_and_stats(ibuf, n, obs, outfile))
408 if (flags & FLAG_FSYNC) {
414 if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
415 w = full_write_or_warn(obuf, oc, outfile);
416 if (w < 0) goto out_status;
417 if (w > 0) G.out_part++;
419 if (close(ifd) < 0) {
421 bb_simple_perror_msg_and_die(infile);
424 if (close(ofd) < 0) {
426 bb_simple_perror_msg_and_die(outfile);
429 exitcode = EXIT_SUCCESS;
433 if (ENABLE_FEATURE_CLEAN_UP) {
435 if (flags & FLAG_TWOBUFS)