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 Copy/convert files.
20
21 if=FILE Read from FILE instead of stdin
22 of=FILE Write to FILE instead of stdout
23 bs=N Read and write N bytes at a time
24 ibs=N Read N bytes at a time
25 obs=N Write N bytes at a time
26 count=N Copy only N input blocks
27 skip=N Skip N input blocks
28 seek=N Skip N output blocks
29 conv=notrunc Don't truncate output file
30 conv=noerror Continue after read errors
31 conv=sync Pad blocks with zeros
32 conv=fsync Physically write data out before finishing
33 status=noxfer Don't show transfer rate
34 status=none Don't show transfer rate or records in/out
35
36 Numbers may be suffixed by c (*1), w (*2), b (*512), kD (*1000), k (*1024),
37 MD (*1000*1000), M (*1024*1024), GD (*1000*1000*1000) or G (*1024*1024*1024).
38 */
39
40 #define FOR_dd
41 #include "toys.h"
42
43 GLOBALS(
44 int show_xfer, show_records;
45 unsigned long long bytes, c_count, in_full, in_part, out_full, out_part;
46 struct timeval start;
47 struct {
48 char *name;
49 int fd;
50 unsigned char *buff, *bp;
51 long sz, count;
52 unsigned long long offset;
53 } in, out;
54 );
55
56 #define C_FSYNC 1
57 #define C_NOERROR 2
58 #define C_NOTRUNC 4
59 #define C_SYNC 8
60
status()61 static void status()
62 {
63 double seconds;
64 struct timeval now;
65
66 gettimeofday(&now, NULL);
67 seconds = ((now.tv_sec * 1000000 + now.tv_usec) -
68 (TT.start.tv_sec * 1000000 + TT.start.tv_usec))/1000000.0;
69
70 if (TT.show_records)
71 fprintf(stderr, "%llu+%llu records in\n%llu+%llu records out\n",
72 TT.in_full, TT.in_part, TT.out_full, TT.out_part);
73
74 if (TT.show_xfer) {
75 human_readable(toybuf, TT.bytes, HR_SPACE|HR_B);
76 fprintf(stderr, "%llu bytes (%s) copied, ", TT.bytes, toybuf);
77 human_readable(toybuf, TT.bytes/seconds, HR_SPACE|HR_B);
78 fprintf(stderr, "%f s, %s/s\n", seconds, toybuf);
79 }
80 }
81
write_out(int all)82 static void write_out(int all)
83 {
84 TT.out.bp = TT.out.buff;
85 while (TT.out.count) {
86 ssize_t nw = writeall(TT.out.fd, TT.out.bp, ((all)? TT.out.count : TT.out.sz));
87
88 all = 0; //further writes will be on obs
89 if (nw <= 0) perror_exit("%s: write error", TT.out.name);
90 if (nw == TT.out.sz) TT.out_full++;
91 else TT.out_part++;
92 TT.out.count -= nw;
93 TT.out.bp += nw;
94 TT.bytes += nw;
95 if (TT.out.count < TT.out.sz) break;
96 }
97 if (TT.out.count) memmove(TT.out.buff, TT.out.bp, TT.out.count); //move remainder to front
98 }
99
strstarteq(char ** a,char * b)100 int strstarteq(char **a, char *b)
101 {
102 char *aa = *a;
103
104 return strstart(&aa, b) && *aa == '=' && (*a = aa+1);
105 }
106
dd_main()107 void dd_main()
108 {
109 char **args;
110 unsigned long long bs = 0;
111 int trunc = O_TRUNC, conv = 0;
112
113 TT.show_xfer = TT.show_records = 1;
114 TT.c_count = ULLONG_MAX;
115
116 TT.in.sz = TT.out.sz = 512; //default io block size
117 for (args = toys.optargs; *args; args++) {
118 char *arg = *args;
119
120 if (strstarteq(&arg, "bs")) bs = atolx_range(arg, 1, LONG_MAX);
121 else if (strstarteq(&arg, "ibs")) TT.in.sz = atolx_range(arg, 1, LONG_MAX);
122 else if (strstarteq(&arg, "obs")) TT.out.sz = atolx_range(arg, 1, LONG_MAX);
123 else if (strstarteq(&arg, "count"))
124 TT.c_count = atolx_range(arg, 0, LLONG_MAX);
125 else if (strstarteq(&arg, "if")) TT.in.name = arg;
126 else if (strstarteq(&arg, "of")) TT.out.name = arg;
127 else if (strstarteq(&arg, "seek"))
128 TT.out.offset = atolx_range(arg, 0, LLONG_MAX);
129 else if (strstarteq(&arg, "skip"))
130 TT.in.offset = atolx_range(arg, 0, LLONG_MAX);
131 else if (strstarteq(&arg, "status")) {
132 if (!strcmp(arg, "noxfer")) TT.show_xfer = 0;
133 else if (!strcmp(arg, "none")) TT.show_xfer = TT.show_records = 0;
134 else error_exit("unknown status '%s'", arg);
135 } else if (strstarteq(&arg, "conv")) {
136 char *ss, *convs[] = {"fsync", "noerror", "notrunc", "sync"};
137 int i, len;
138
139 while ((ss = comma_iterate(&arg, &len))) {
140 for (i = 0; i<ARRAY_LEN(convs); i++)
141 if (len == strlen(convs[i]) && !strncmp(ss, convs[i], len)) break;
142 if (i == ARRAY_LEN(convs)) error_exit("bad conv=%.*s", len, ss);
143 conv |= 1<<i;
144 }
145 } else error_exit("bad arg %s", arg);
146 }
147 if (bs) TT.in.sz = TT.out.sz = bs;
148
149 signal(SIGINT, generic_signal);
150 signal(SIGUSR1, generic_signal);
151 gettimeofday(&TT.start, NULL);
152
153 /* for bs=, in/out is done as it is. so only in.sz is enough.
154 * With Single buffer there will be overflow in a read following partial read
155 */
156 TT.in.buff = TT.out.buff = xmalloc(TT.in.sz + (bs ? 0 : TT.out.sz));
157 TT.in.bp = TT.out.bp = TT.in.buff;
158 //setup input
159 if (!TT.in.name) TT.in.name = "stdin";
160 else TT.in.fd = xopenro(TT.in.name);
161
162 if (conv&C_NOTRUNC) trunc = 0;
163
164 //setup output
165 if (!TT.out.name) {
166 TT.out.name = "stdout";
167 TT.out.fd = 1;
168 } else TT.out.fd = xcreate(TT.out.name,
169 O_WRONLY|O_CREAT|(trunc*!TT.out.offset), 0666);
170
171 // Implement skip=
172 if (TT.in.offset) {
173 if (lseek(TT.in.fd, (off_t)(TT.in.offset * TT.in.sz), SEEK_CUR) < 0) {
174 while (TT.in.offset--) {
175 ssize_t n = read(TT.in.fd, TT.in.bp, TT.in.sz);
176
177 if (n < 0) {
178 perror_msg("%s", TT.in.name);
179 if (conv&C_NOERROR) status();
180 else return;
181 } else if (!n) {
182 xprintf("%s: Can't skip\n", TT.in.name);
183 return;
184 }
185 }
186 }
187 }
188
189 // seek/truncate as necessary. We handled position zero truncate with
190 // O_TRUNC on open, so output to /dev/null and such doesn't error.
191 if (TT.out.fd!=1 && (bs = TT.out.offset*TT.out.sz)) {
192 xlseek(TT.out.fd, bs, SEEK_CUR);
193 if (trunc && ftruncate(TT.out.fd, bs)) perror_exit("ftruncate");
194 }
195
196 while (TT.c_count==ULLONG_MAX || (TT.in_full + TT.in_part) < TT.c_count) {
197 ssize_t n;
198
199 // Show progress and exit on SIGINT or just continue on SIGUSR1.
200 if (toys.signal) {
201 status();
202 if (toys.signal==SIGINT) exit_signal(toys.signal);
203 toys.signal = 0;
204 }
205
206 TT.in.bp = TT.in.buff + TT.in.count;
207 if (conv&C_SYNC) memset(TT.in.bp, 0, TT.in.sz);
208 if (!(n = read(TT.in.fd, TT.in.bp, TT.in.sz))) break;
209 if (n < 0) {
210 if (errno == EINTR) continue;
211 //read error case.
212 perror_msg("%s: read error", TT.in.name);
213 if (!(conv&C_NOERROR)) exit(1);
214 status();
215 xlseek(TT.in.fd, TT.in.sz, SEEK_CUR);
216 if (!(conv&C_SYNC)) continue;
217 // if SYNC, then treat as full block of nuls
218 n = TT.in.sz;
219 }
220 if (n == TT.in.sz) {
221 TT.in_full++;
222 TT.in.count += n;
223 } else {
224 TT.in_part++;
225 if (conv&C_SYNC) TT.in.count += TT.in.sz;
226 else TT.in.count += n;
227 }
228
229 TT.out.count = TT.in.count;
230 if (bs) {
231 write_out(1);
232 TT.in.count = 0;
233 continue;
234 }
235
236 if (TT.in.count >= TT.out.sz) {
237 write_out(0);
238 TT.in.count = TT.out.count;
239 }
240 }
241 if (TT.out.count) write_out(1); //write any remaining input blocks
242 if ((conv&C_FSYNC) && fsync(TT.out.fd)<0)
243 perror_exit("%s: fsync", TT.out.name);
244
245 close(TT.in.fd);
246 close(TT.out.fd);
247 if (TT.in.buff) free(TT.in.buff);
248
249 status();
250 }
251