1 /* dd.c - program to convert and copy a file.
2 *
3 * Copyright 2013 Ashwini Kumar <ak.ashwini@gmail.com>
4 * Copyright 2013 Kyungwan Han <asura321@gmail.com>
5 *
6 * See http://opengroup.org/onlinepubs/9699919799/utilities/dd.html
7 USE_DD(NEWTOY(dd, NULL, TOYFLAG_USR|TOYFLAG_BIN))
8
9 config DD
10 bool "dd"
11 default n
12 help
13 usage: dd [if=FILE] [of=FILE] [ibs=N] [obs=N] [bs=N] [count=N] [skip=N]
14 [seek=N] [conv=notrunc|noerror|sync|fsync]
15
16 Options:
17 if=FILE Read from FILE instead of stdin
18 of=FILE Write to FILE instead of stdout
19 bs=N Read and write N bytes at a time
20 ibs=N Read N bytes at a time
21 obs=N Write N bytes at a time
22 count=N Copy only N input blocks
23 skip=N Skip N input blocks
24 seek=N Skip N output blocks
25 conv=notrunc Don't truncate output file
26 conv=noerror Continue after read errors
27 conv=sync Pad blocks with zeros
28 conv=fsync Physically write data out before finishing
29
30 Numbers may be suffixed by c (x1), w (x2), b (x512), kD (x1000), k (x1024),
31 MD (x1000000), M (x1048576), GD (x1000000000) or G (x1073741824)
32 Copy a file, converting and formatting according to the operands.
33 */
34 #define FOR_dd
35 #include "toys.h"
36
37 GLOBALS(
38 int sig;
39 )
40 #define C_CONV 0x0000
41 #define C_BS 0x0001
42 #define C_COUNT 0x0002
43 #define C_IBS 0x0004
44 #define C_OBS 0x0008
45 #define C_IF 0x0010
46 #define C_OF 0x0020
47 #define C_SEEK 0x0040
48 #define C_SKIP 0x0080
49 #define C_SYNC 0x0100
50 #define C_FSYNC 0x0200
51 #define C_NOERROR 0x0400
52 #define C_NOTRUNC 0x0800
53
54 struct io {
55 char *name;
56 int fd;
57 unsigned char *buff, *bp;
58 long sz, count;
59 unsigned long long offset;
60 };
61
62 struct iostat {
63 unsigned long long in_full, in_part, out_full, out_part, bytes;
64 struct timeval start;
65 };
66
67 struct pair {
68 char *name;
69 unsigned val;
70 };
71
72 static struct pair suffixes[] = {
73 { "c", 1 }, { "w", 2 }, { "b", 512 },
74 { "kD", 1000 }, { "k", 1024 }, { "K", 1024 },
75 { "MD", 1000000 }, { "M", 1048576 },
76 { "GD", 1000000000 }, { "G", 1073741824 }
77 };
78
79 static struct pair clist[] = {
80 { "fsync", C_FSYNC },
81 { "noerror", C_NOERROR },
82 { "notrunc", C_NOTRUNC },
83 { "sync", C_SYNC },
84 };
85
86 static struct pair operands[] = {
87 // keep the array sorted by name, bsearch() can be used.
88 { "bs", C_BS },
89 { "conv", C_CONV },
90 { "count", C_COUNT},
91 { "ibs", C_IBS },
92 { "if", C_IF },
93 { "obs", C_OBS },
94 { "of", C_OF },
95 { "seek", C_SEEK },
96 { "skip", C_SKIP },
97 };
98
99 static struct io in, out;
100 static struct iostat st;
101 static unsigned long long c_count;
102
strsuftoll(char * arg,int def,unsigned long long max)103 static unsigned long long strsuftoll(char* arg, int def, unsigned long long max)
104 {
105 unsigned long long result;
106 char *endp, *ch = arg;
107 int i, idx = -1;
108 errno = 0;
109
110 while (isspace(*ch)) ch++;
111 if (*ch == '-') error_exit("invalid number '%s'",arg);
112 result = strtoull(arg, &endp, 10);
113 if (errno == ERANGE || result > max || result < def)
114 perror_exit("invalid number '%s'",arg);
115 if (*endp != '\0') {
116 for (i = 0; i < ARRAY_LEN(suffixes); i++)
117 if (!strcmp(endp, suffixes[i].name)) idx = i;
118 if (idx == -1 || (max/suffixes[idx].val < result))
119 error_exit("invalid number '%s'",arg);
120 result = result* suffixes[idx].val;
121 }
122 return result;
123 }
124
summary()125 static void summary()
126 {
127 double seconds = 5.0;
128 struct timeval now;
129
130 gettimeofday(&now, NULL);
131 seconds = ((now.tv_sec * 1000000 + now.tv_usec) - (st.start.tv_sec * 1000000
132 + st.start.tv_usec))/1000000.0;
133 //out to STDERR
134 fprintf(stderr,"%llu+%llu records in\n%llu+%llu records out\n", st.in_full, st.in_part,
135 st.out_full, st.out_part);
136 human_readable(toybuf, st.bytes, HR_SPACE|HR_B);
137 fprintf(stderr, "%llu bytes (%s) copied, ",st.bytes, toybuf);
138 human_readable(toybuf, st.bytes/seconds, HR_SPACE|HR_B);
139 fprintf(stderr, "%f s, %s/s\n", seconds, toybuf);
140 }
141
sig_handler(int sig)142 static void sig_handler(int sig)
143 {
144 TT.sig = sig;
145 }
146
xmove_fd(int fd)147 static int xmove_fd(int fd)
148 {
149 int newfd;
150
151 if (fd > STDERR_FILENO) return fd;
152 if ((newfd = fcntl(fd, F_DUPFD, 3) < 0)) perror_exit("dupfd IO");
153 close(fd);
154 return newfd;
155 }
156
setup_inout()157 static void setup_inout()
158 {
159 ssize_t n;
160
161 /* for C_BS, in/out is done as it is. so only in.sz is enough.
162 * With Single buffer there will be overflow in a read following partial read
163 */
164 in.buff = out.buff = xmalloc(in.sz + ((toys.optflags & C_BS)? 0: out.sz));
165 in.bp = out.bp = in.buff;
166 atexit(summary);
167 //setup input
168 if (!in.name) {
169 in.name = "stdin";
170 in.fd = STDIN_FILENO;
171 } else {
172 in.fd = xopen(in.name, O_RDONLY);
173 in.fd = xmove_fd(in.fd);
174 }
175 //setup outout
176 if (!out.name) {
177 out.name = "stdout";
178 out.fd = STDOUT_FILENO;
179 } else {
180 out.fd = xcreate(out.name, O_WRONLY | O_CREAT, 0666);
181 out.fd = xmove_fd(out.fd);
182 }
183
184 if (in.offset) {
185 if (lseek(in.fd, (off_t)(in.offset * in.sz), SEEK_CUR) < 0) {
186 while (in.offset--) {
187 if ((n = read(in.fd, in.bp, in.sz)) < 0) {
188 if (toys.optflags & C_NOERROR) { //warn message and summary
189 error_msg("%s: read error", in.name);
190 summary();
191 } else perror_exit("%s: read error", in.name);
192 } else if (!n) {
193 xprintf("%s: Can't skip\n", in.name);
194 exit(0);
195 }
196 }
197 }
198 }
199
200 if (out.offset) xlseek(out.fd, (off_t)(out.offset * out.sz), SEEK_CUR);
201 }
202
write_out(int all)203 static void write_out(int all)
204 {
205 ssize_t nw;
206 out.bp = out.buff;
207 while (out.count) {
208 nw = writeall(out.fd, out.bp, ((all)? out.count : out.sz));
209 all = 0; //further writes will be on obs
210 if (nw <= 0) perror_exit("%s: write error",out.name);
211 if (nw == out.sz) st.out_full++;
212 else st.out_part++;
213 out.count -= nw;
214 out.bp += nw;
215 st.bytes += nw;
216 if (out.count < out.sz) break;
217 }
218 if (out.count) memmove(out.buff, out.bp, out.count); //move remainder to front
219 }
220
do_dd(void)221 static void do_dd(void)
222 {
223 ssize_t n;
224 struct sigaction sa;
225
226 memset(&sa, 0, sizeof(sa));
227 sa.sa_handler = sig_handler;
228 sigaction(SIGINT, &sa, NULL);
229 sigaction(SIGUSR1, &sa, NULL);
230 setup_inout();
231 gettimeofday(&st.start, NULL);
232
233 if (toys.optflags & (C_OF | C_SEEK) && !(toys.optflags & C_NOTRUNC))
234 ftruncate(out.fd, (off_t)out.offset * out.sz);
235
236 while (!(toys.optflags & C_COUNT) || (st.in_full + st.in_part) < c_count) {
237 if (TT.sig == SIGUSR1) {
238 summary();
239 TT.sig = 0;
240 } else if (TT.sig == SIGINT) exit(TT.sig | 128);
241 in.bp = in.buff + in.count;
242 if (toys.optflags & C_SYNC) memset(in.bp, 0, in.sz);
243 if (!(n = read(in.fd, in.bp, in.sz))) break;
244 if (n < 0) {
245 if (errno == EINTR) continue;
246 //read error case.
247 perror_msg("%s: read error", in.name);
248 if (!(toys.optflags & C_NOERROR)) exit(1);
249 summary();
250 xlseek(in.fd, in.sz, SEEK_CUR);
251 if (!(toys.optflags & C_SYNC)) continue;
252 // if SYNC, then treat as full block of nuls
253 n = in.sz;
254 }
255 if (n == in.sz) {
256 st.in_full++;
257 in.count += n;
258 } else {
259 st.in_part++;
260 if (toys.optflags & C_SYNC) in.count += in.sz;
261 else in.count += n;
262 }
263
264 out.count = in.count;
265 if (toys.optflags & C_BS) {
266 write_out(1);
267 in.count = 0;
268 continue;
269 }
270
271 if (in.count >= out.sz) {
272 write_out(0);
273 in.count = out.count;
274 }
275 }
276 if (out.count) write_out(1); //write any remaining input blocks
277 if (toys.optflags & C_FSYNC && fsync(out.fd) < 0)
278 perror_exit("%s: fsync fail", out.name);
279
280 close(in.fd);
281 close(out.fd);
282 if (in.buff) free(in.buff);
283 }
284
comp(const void * a,const void * b)285 static int comp(const void *a, const void *b) //const to shut compiler up
286 {
287 return strcmp(((struct pair*)a)->name, ((struct pair*)b)->name);
288 }
289
dd_main()290 void dd_main()
291 {
292 struct pair *res, key;
293 char *arg;
294 long sz;
295
296 in.sz = out.sz = 512; //default io block size
297 while (*toys.optargs) {
298 if (!(arg = strchr(*toys.optargs, '='))) error_exit("unknown arg %s", *toys.optargs);
299 *arg++ = '\0';
300 if (!*arg) help_exit(0);
301 key.name = *toys.optargs;
302 if (!(res = bsearch(&key, operands, ARRAY_LEN(operands), sizeof(struct pair),
303 comp))) error_exit("unknown arg %s", key.name);
304
305 toys.optflags |= res->val;
306 switch(res->val) {
307 case C_BS:
308 in.sz = out.sz = strsuftoll(arg, 1, LONG_MAX);
309 break;
310 case C_IBS:
311 sz = strsuftoll(arg, 1, LONG_MAX);
312 if (!(toys.optflags & C_BS)) in.sz = sz;
313 break;
314 case C_OBS:
315 sz = strsuftoll(arg, 1, LONG_MAX);
316 if (!(toys.optflags & C_BS)) out.sz = sz;
317 break;
318 case C_COUNT:
319 c_count = strsuftoll(arg, 0, ULLONG_MAX);
320 break;
321 case C_IF:
322 in.name = arg;
323 break;
324 case C_OF:
325 out.name = arg;
326 break;
327 case C_SEEK:
328 out.offset = strsuftoll(arg, 0, ULLONG_MAX);
329 break;
330 case C_SKIP:
331 in.offset = strsuftoll(arg, 0, ULLONG_MAX);
332 break;
333 case C_CONV:
334 while (arg) {
335 key.name = strsep(&arg, ",");
336 if (!(res = bsearch(&key, clist, ARRAY_LEN(clist),
337 sizeof(struct pair), comp)))
338 error_exit("unknown conversion %s", key.name);
339
340 toys.optflags |= res->val;
341 }
342 break;
343 }
344 toys.optargs++;
345 }
346
347 do_dd();
348 }
349