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      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