1 /* dd.c - program to convert and copy a file. 2 * 3 * Copyright 2013 Ashwini Kumar <ak.ashwini (at) gmail.com> 4 * Copyright 2013 Kyungwan Han <asura321 (at) 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 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 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 99 int strstarteq(char **a, char *b) 100 { 101 char *aa = *a; 102 103 return strstart(&aa, b) && *aa == '=' && (*a = aa+1); 104 } 105 106 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