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 *
8 * todo: ctrl-c doesn't work, the read() is restarting.
9
10 USE_DD(NEWTOY(dd, 0, TOYFLAG_USR|TOYFLAG_BIN))
11
12 config DD
13 bool "dd"
14 default n
15 help
16 usage: dd [if=FILE] [of=FILE] [ibs=N] [obs=N] [bs=N] [count=N] [skip=N]
17 [seek=N] [conv=notrunc|noerror|sync|fsync] [status=noxfer|none]
18
19 Options:
20 if=FILE Read from FILE instead of stdin
21 of=FILE Write to FILE instead of stdout
22 bs=N Read and write N bytes at a time
23 ibs=N Read N bytes at a time
24 obs=N Write N bytes at a time
25 count=N Copy only N input blocks
26 skip=N Skip N input blocks
27 seek=N Skip N output blocks
28 conv=notrunc Don't truncate output file
29 conv=noerror Continue after read errors
30 conv=sync Pad blocks with zeros
31 conv=fsync Physically write data out before finishing
32 status=noxfer Don't show transfer rate
33 status=none Don't show transfer rate or records in/out
34
35 Numbers may be suffixed by c (*1), w (*2), b (*512), kD (*1000), k (*1024),
36 MD (*1000*1000), M (*1024*1024), GD (*1000*1000*1000) or G (*1024*1024*1024).
37 */
38
39 #define FOR_dd
40 #include "toys.h"
41
42 GLOBALS(
43 int show_xfer, show_records;
44 unsigned long long bytes, c_count, in_full, in_part, out_full, out_part;
45 struct timeval start;
46 struct {
47 char *name;
48 int fd;
49 unsigned char *buff, *bp;
50 long sz, count;
51 unsigned long long offset;
52 } in, out;
53 );
54
55 #define C_FSYNC 1
56 #define C_NOERROR 2
57 #define C_NOTRUNC 4
58 #define C_SYNC 8
59
status()60 static void status()
61 {
62 double seconds;
63 struct timeval now;
64
65 gettimeofday(&now, NULL);
66 seconds = ((now.tv_sec * 1000000 + now.tv_usec) -
67 (TT.start.tv_sec * 1000000 + TT.start.tv_usec))/1000000.0;
68
69 if (TT.show_records)
70 fprintf(stderr, "%llu+%llu records in\n%llu+%llu records out\n",
71 TT.in_full, TT.in_part, TT.out_full, TT.out_part);
72
73 if (TT.show_xfer) {
74 human_readable(toybuf, TT.bytes, HR_SPACE|HR_B);
75 fprintf(stderr, "%llu bytes (%s) copied, ", TT.bytes, toybuf);
76 human_readable(toybuf, TT.bytes/seconds, HR_SPACE|HR_B);
77 fprintf(stderr, "%f s, %s/s\n", seconds, toybuf);
78 }
79 }
80
write_out(int all)81 static void write_out(int all)
82 {
83 TT.out.bp = TT.out.buff;
84 while (TT.out.count) {
85 ssize_t nw = writeall(TT.out.fd, TT.out.bp, ((all)? TT.out.count : TT.out.sz));
86
87 all = 0; //further writes will be on obs
88 if (nw <= 0) perror_exit("%s: write error", TT.out.name);
89 if (nw == TT.out.sz) TT.out_full++;
90 else TT.out_part++;
91 TT.out.count -= nw;
92 TT.out.bp += nw;
93 TT.bytes += nw;
94 if (TT.out.count < TT.out.sz) break;
95 }
96 if (TT.out.count) memmove(TT.out.buff, TT.out.bp, TT.out.count); //move remainder to front
97 }
98
strstarteq(char ** a,char * b)99 int strstarteq(char **a, char *b)
100 {
101 char *aa = *a;
102
103 return strstart(&aa, b) && *aa == '=' && (*a = aa+1);
104 }
105
dd_main()106 void dd_main()
107 {
108 char **args;
109 unsigned long long bs = 0;
110 int trunc = O_TRUNC, conv = 0;
111
112 TT.show_xfer = TT.show_records = 1;
113 TT.c_count = ULLONG_MAX;
114
115 TT.in.sz = TT.out.sz = 512; //default io block size
116 for (args = toys.optargs; *args; args++) {
117 char *arg = *args;
118
119 if (strstarteq(&arg, "bs")) bs = atolx_range(arg, 1, LONG_MAX);
120 else if (strstarteq(&arg, "ibs")) TT.in.sz = atolx_range(arg, 1, LONG_MAX);
121 else if (strstarteq(&arg, "obs")) TT.out.sz = atolx_range(arg, 1, LONG_MAX);
122 else if (strstarteq(&arg, "count"))
123 TT.c_count = atolx_range(arg, 0, LLONG_MAX);
124 else if (strstarteq(&arg, "if")) TT.in.name = arg;
125 else if (strstarteq(&arg, "of")) TT.out.name = arg;
126 else if (strstarteq(&arg, "seek"))
127 TT.out.offset = atolx_range(arg, 0, LLONG_MAX);
128 else if (strstarteq(&arg, "skip"))
129 TT.in.offset = atolx_range(arg, 0, LLONG_MAX);
130 else if (strstarteq(&arg, "status")) {
131 if (!strcmp(arg, "noxfer")) TT.show_xfer = 0;
132 else if (!strcmp(arg, "none")) TT.show_xfer = TT.show_records = 0;
133 else error_exit("unknown status '%s'", arg);
134 } else if (strstarteq(&arg, "conv")) {
135 char *ss, *convs[] = {"fsync", "noerror", "notrunc", "sync"};
136 int i, len;
137
138 while ((ss = comma_iterate(&arg, &len))) {
139 for (i = 0; i<ARRAY_LEN(convs); i++)
140 if (len == strlen(convs[i]) && !strncmp(ss, convs[i], len)) break;
141 if (i == ARRAY_LEN(convs)) error_exit("bad conv=%.*s", len, ss);
142 conv |= 1<<i;
143 }
144 } else error_exit("bad arg %s", arg);
145 }
146 if (bs) TT.in.sz = TT.out.sz = bs;
147
148 signal(SIGINT, generic_signal);
149 signal(SIGUSR1, generic_signal);
150 gettimeofday(&TT.start, NULL);
151
152 /* for bs=, in/out is done as it is. so only in.sz is enough.
153 * With Single buffer there will be overflow in a read following partial read
154 */
155 TT.in.buff = TT.out.buff = xmalloc(TT.in.sz + (bs ? 0 : TT.out.sz));
156 TT.in.bp = TT.out.bp = TT.in.buff;
157 //setup input
158 if (!TT.in.name) TT.in.name = "stdin";
159 else TT.in.fd = xopenro(TT.in.name);
160
161 if (conv&C_NOTRUNC) trunc = 0;
162
163 //setup output
164 if (!TT.out.name) {
165 TT.out.name = "stdout";
166 TT.out.fd = 1;
167 } else TT.out.fd = xcreate(TT.out.name,
168 O_WRONLY|O_CREAT|(trunc*!TT.out.offset), 0666);
169
170 // Implement skip=
171 if (TT.in.offset) {
172 if (lseek(TT.in.fd, (off_t)(TT.in.offset * TT.in.sz), SEEK_CUR) < 0) {
173 while (TT.in.offset--) {
174 ssize_t n = read(TT.in.fd, TT.in.bp, TT.in.sz);
175
176 if (n < 0) {
177 perror_msg("%s", TT.in.name);
178 if (conv&C_NOERROR) status();
179 else return;
180 } else if (!n) {
181 xprintf("%s: Can't skip\n", TT.in.name);
182 return;
183 }
184 }
185 }
186 }
187
188 // seek/truncate as necessary. We handled position zero truncate with
189 // O_TRUNC on open, so output to /dev/null and such doesn't error.
190 if (TT.out.fd!=1 && (bs = TT.out.offset*TT.out.sz)) {
191 xlseek(TT.out.fd, bs, SEEK_CUR);
192 if (trunc && ftruncate(TT.out.fd, bs)) perror_exit("ftruncate");
193 }
194
195 while (TT.c_count==ULLONG_MAX || (TT.in_full + TT.in_part) < TT.c_count) {
196 ssize_t n;
197
198 // Show progress and exit on SIGINT or just continue on SIGUSR1.
199 if (toys.signal) {
200 status();
201 if (toys.signal==SIGINT) exit_signal(toys.signal);
202 toys.signal = 0;
203 }
204
205 TT.in.bp = TT.in.buff + TT.in.count;
206 if (conv&C_SYNC) memset(TT.in.bp, 0, TT.in.sz);
207 if (!(n = read(TT.in.fd, TT.in.bp, TT.in.sz))) break;
208 if (n < 0) {
209 if (errno == EINTR) continue;
210 //read error case.
211 perror_msg("%s: read error", TT.in.name);
212 if (!(conv&C_NOERROR)) exit(1);
213 status();
214 xlseek(TT.in.fd, TT.in.sz, SEEK_CUR);
215 if (!(conv&C_SYNC)) continue;
216 // if SYNC, then treat as full block of nuls
217 n = TT.in.sz;
218 }
219 if (n == TT.in.sz) {
220 TT.in_full++;
221 TT.in.count += n;
222 } else {
223 TT.in_part++;
224 if (conv&C_SYNC) TT.in.count += TT.in.sz;
225 else TT.in.count += n;
226 }
227
228 TT.out.count = TT.in.count;
229 if (bs) {
230 write_out(1);
231 TT.in.count = 0;
232 continue;
233 }
234
235 if (TT.in.count >= TT.out.sz) {
236 write_out(0);
237 TT.in.count = TT.out.count;
238 }
239 }
240 if (TT.out.count) write_out(1); //write any remaining input blocks
241 if ((conv&C_FSYNC) && fsync(TT.out.fd)<0)
242 perror_exit("%s: fsync", TT.out.name);
243
244 close(TT.in.fd);
245 close(TT.out.fd);
246 if (TT.in.buff) free(TT.in.buff);
247
248 status();
249 }
250