patches/dd_ibs_and_obs.diff

   1 This patch adds support of ibs= and obs= to dd.
   2 ----
   3 Hideki IWAMOTO  h-iwamoto@kit.hi-ho.ne.jp
   4
   5
   6 --- a/include/usage.h   29 Mar 2004 08:20:08 -0000      1.198
   7 +++ b/include/usage.h   4 Apr 2004 07:15:21 -0000
   8 @@ -309,13 +309,15 @@
   9         "64\n"
  10
  11  #define dd_trivial_usage \
  12 -       "[if=FILE] [of=FILE] [bs=N] [count=N] [skip=N]\n" \
  13 -       "\t  [seek=N] [conv=notrunc|noerror|sync]"
  14 +       "[if=FILE] [of=FILE] [ibs=N] [obs=N] [bs=N] [count=N]\n" \
  15 +       "\t  [skip=N] [seek=N] [conv=notrunc|noerror|sync]"
  16  #define dd_full_usage \
  17         "Copy a file, converting and formatting according to options\n\n" \
  18         "\tif=FILE\t\tread from FILE instead of stdin\n" \
  19         "\tof=FILE\t\twrite to FILE instead of stdout\n" \
  20 -       "\tbs=N\t\tread and write N bytes at a time\n" \
  21 +       "\tibs=N\t\tread N bytes at a time\n" \
  22 +       "\tobs=N\t\twrite N bytes at a time\n" \
  23 +       "\tbs=N\t\tforce ibs=N and obs=N\n" \
  24         "\tcount=N\t\tcopy only N input blocks\n" \
  25         "\tskip=N\t\tskip N input blocks\n" \
  26         "\tseek=N\t\tskip N output blocks\n" \
  27 @@ -323,6 +325,8 @@
  28         "\tconv=noerror\tcontinue after read errors\n" \
  29         "\tconv=sync\tpad blocks with zeros\n" \
  30         "\n" \
  31 +       "If the bs= expr operand is not specified, the input is processed and collected\n" \
  32 +       "into full-sized output blocks until the end of the input is reached.\n" \
  33         "Numbers may be suffixed by c (x1), w (x2), b (x512), kD (x1000), k (x1024),\n" \
  34         "MD (x1000000), M (x1048576), GD (x1000000000) or G (x1073741824)."
  35  #define dd_example_usage \
  36 --- a/coreutils/dd.c    30 Jan 2004 22:24:32 -0000      1.55
  37 +++ b/coreutils/dd.c    4 Apr 2004 07:15:21 -0000
  38 @@ -30,6 +30,10 @@
  39  #include <fcntl.h>
  40  #include "busybox.h"
  41
  42 +#define C_NOERROR      0x0001
  43 +#define C_TRUNC                0x0002
  44 +#define C_SYNC         0x0004
  45 +#define C_TWOBUFS      0x0008
  46
  47  static const struct suffix_mult dd_suffixes[] = {
  48         { "c", 1 },
  49 @@ -51,13 +55,13 @@
  50         size_t in_full = 0;
  51         size_t in_part = 0;
  52         size_t count = -1;
  53 -       size_t bs = 512;
  54 +       size_t ibs = 512;
  55 +       size_t obs = 512;
  56 +       size_t oc = 0;
  57         ssize_t n;
  58         off_t seek = 0;
  59         off_t skip = 0;
  60 -       int sync_flag = FALSE;
  61 -       int noerror = FALSE;
  62 -       int trunc_flag = TRUE;
  63 +       unsigned int dd_flags = C_TWOBUFS | C_TRUNC;
  64         int oflag;
  65         int ifd;
  66         int ofd;
  67 @@ -65,11 +69,18 @@
  68         const char *infile = NULL;
  69         const char *outfile = NULL;
  70         char *buf;
  71 +       char *ibuf;
  72 +       char *obuf;
  73
  74         for (i = 1; i < argc; i++) {
  75 -               if (strncmp("bs=", argv[i], 3) == 0)
  76 -                       bs = bb_xparse_number(argv[i]+3, dd_suffixes);
  77 -               else if (strncmp("count=", argv[i], 6) == 0)
  78 +               if (strncmp("ibs=", argv[i], 4) == 0)
  79 +                       ibs = bb_xparse_number(argv[i]+4, dd_suffixes);
  80 +               else if (strncmp("obs=", argv[i], 4) == 0)
  81 +                       obs = bb_xparse_number(argv[i]+4, dd_suffixes);
  82 +               else if (strncmp("bs=", argv[i], 3) == 0) {
  83 +                       ibs = obs = bb_xparse_number(argv[i]+3, dd_suffixes);
  84 +                       dd_flags &= ~C_TWOBUFS;
  85 +               } else if (strncmp("count=", argv[i], 6) == 0)
  86                         count = bb_xparse_number(argv[i]+6, dd_suffixes);
  87                 else if (strncmp("seek=", argv[i], 5) == 0)
  88                         seek = bb_xparse_number(argv[i]+5, dd_suffixes);
  89 @@ -83,13 +94,13 @@
  90                         buf = argv[i]+5;
  91                         while (1) {
  92                                 if (strncmp("notrunc", buf, 7) == 0) {
  93 -                                       trunc_flag = FALSE;
  94 +                                       dd_flags &= ~C_TRUNC;
  95                                         buf += 7;
  96                                 } else if (strncmp("sync", buf, 4) == 0) {
  97 -                                       sync_flag = TRUE;
  98 +                                       dd_flags |= C_SYNC;
  99                                         buf += 4;
 100                                 } else if (strncmp("noerror", buf, 7) == 0) {
 101 -                                       noerror = TRUE;
 102 +                                       dd_flags |= C_NOERROR;
 103                                         buf += 7;
 104                                 } else {
 105                                         bb_error_msg_and_die("invalid conversion `%s'", argv[i]+5);
 106 @@ -103,7 +114,12 @@
 107                         bb_show_usage();
 108         }
 109
 110 -       buf = xmalloc(bs);
 111 +       ibuf = xmalloc(ibs);
 112 +
 113 +       if (dd_flags & C_TWOBUFS)
 114 +               obuf = xmalloc(obs);
 115 +       else
 116 +               obuf = ibuf;
 117
 118         if (infile != NULL) {
 119                 ifd = bb_xopen(infile, O_RDONLY);
 120 @@ -115,7 +131,7 @@
 121         if (outfile != NULL) {
 122                 oflag = O_WRONLY | O_CREAT;
 123
 124 -               if (!seek && trunc_flag) {
 125 +               if (!seek && (dd_flags & C_TRUNC)) {
 126                         oflag |= O_TRUNC;
 127                 }
 128
 129 @@ -123,8 +139,8 @@
 130                         bb_perror_msg_and_die("%s", outfile);
 131                 }
 132
 133 -               if (seek && trunc_flag) {
 134 -                       if (ftruncate(ofd, seek * bs) < 0) {
 135 +               if (seek && (dd_flags & C_TRUNC)) {
 136 +                       if (ftruncate(ofd, seek * obs) < 0) {
 137                                 struct stat st;
 138
 139                                 if (fstat (ofd, &st) < 0 || S_ISREG (st.st_mode) ||
 140 @@ -139,52 +155,88 @@
 141         }
 142
 143         if (skip) {
 144 -               if (lseek(ifd, skip * bs, SEEK_CUR) < 0) {
 145 -                       bb_perror_msg_and_die("%s", infile);
 146 +               if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
 147 +                       while (skip-- > 0) {
 148 +                               n = safe_read(ifd, ibuf, ibs);
 149 +                               if (n < 0)
 150 +                                       bb_perror_msg_and_die("%s", infile);
 151 +                               if (n == 0)
 152 +                                       break;
 153 +                       }
 154                 }
 155         }
 156
 157         if (seek) {
 158 -               if (lseek(ofd, seek * bs, SEEK_CUR) < 0) {
 159 +               if (lseek(ofd, seek * obs, SEEK_CUR) < 0) {
 160                         bb_perror_msg_and_die("%s", outfile);
 161                 }
 162         }
 163
 164         while (in_full + in_part != count) {
 165 -               if (noerror) {
 166 +               if (dd_flags & C_NOERROR) {
 167                         /* Pre-zero the buffer when doing the noerror thing */
 168 -                       memset(buf, '\0', bs);
 169 +                       memset(ibuf, '\0', ibs);
 170 +               }
 171 +
 172 +               n = safe_read(ifd, ibuf, ibs);
 173 +               if (n == 0) {
 174 +                       break;
 175                 }
 176 -               n = safe_read(ifd, buf, bs);
 177                 if (n < 0) {
 178 -                       if (noerror) {
 179 -                               n = bs;
 180 +                       if (dd_flags & C_NOERROR) {
 181 +                               n = ibs;
 182                                 bb_perror_msg("%s", infile);
 183                         } else {
 184                                 bb_perror_msg_and_die("%s", infile);
 185                         }
 186                 }
 187 -               if (n == 0) {
 188 -                       break;
 189 -               }
 190 -               if (n == bs) {
 191 +               if (n == ibs) {
 192                         in_full++;
 193                 } else {
 194                         in_part++;
 195 +                       if (dd_flags & C_SYNC) {
 196 +                               memset(ibuf + n, '\0', ibs - n);
 197 +                               n = ibs;
 198 +                       }
 199                 }
 200 -               if (sync_flag) {
 201 -                       memset(buf + n, '\0', bs - n);
 202 -                       n = bs;
 203 +
 204 +               if (dd_flags & C_TWOBUFS) {
 205 +                       size_t d;
 206 +                       char *tmp = ibuf;
 207 +
 208 +                       while (n) {
 209 +                               d = obs - oc;
 210 +                               if (d > n)
 211 +                                       d = n;
 212 +                               memcpy(obuf + oc, tmp, d);
 213 +                               n -= d;
 214 +                               tmp += d;
 215 +                               oc += d;
 216 +                               if (oc == obs) {
 217 +                                       if (bb_full_write(ofd, obuf, obs) < 0) {
 218 +                                               bb_perror_msg_and_die("%s", outfile);
 219 +                                       }
 220 +                                       out_full++;
 221 +                                       oc = 0;
 222 +                               }
 223 +                       }
 224 +               } else {
 225 +                       if (bb_full_write(ofd, ibuf, n) < 0) {
 226 +                               bb_perror_msg_and_die("%s", outfile);
 227 +                       }
 228 +                       if (n == ibs) {
 229 +                               out_full++;
 230 +                       } else {
 231 +                               out_part++;
 232 +                       }
 233                 }
 234 -               n = bb_full_write(ofd, buf, n);
 235 -               if (n < 0) {
 236 +       }
 237 +
 238 +       if (oc) {
 239 +               if (bb_full_write(ofd, obuf, oc) < 0) {
 240                         bb_perror_msg_and_die("%s", outfile);
 241                 }
 242 -               if (n == bs) {
 243 -                       out_full++;
 244 -               } else {
 245 -                       out_part++;
 246 -               }
 247 +               out_part++;
 248         }
 249
 250         if (close (ifd) < 0) {
 251
 252