[3320] | 1 | /* vi: set sw=4 ts=4: */
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| 2 | /*
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| 3 | * Mini dd implementation for busybox
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| 4 | *
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| 5 | *
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| 6 | * Copyright (C) 2000,2001 Matt Kraai
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| 7 | *
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| 8 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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| 9 | */
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| 10 |
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| 11 | #include "libbb.h"
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| 12 |
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| 13 | /* This is a NOEXEC applet. Be very careful! */
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| 14 |
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| 15 |
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| 16 | enum {
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| 17 | ifd = STDIN_FILENO,
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| 18 | ofd = STDOUT_FILENO,
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| 19 | };
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| 20 |
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| 21 | static const struct suffix_mult dd_suffixes[] = {
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| 22 | { "c", 1 },
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| 23 | { "w", 2 },
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| 24 | { "b", 512 },
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| 25 | { "kD", 1000 },
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| 26 | { "k", 1024 },
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| 27 | { "K", 1024 }, /* compat with coreutils dd */
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| 28 | { "MD", 1000000 },
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| 29 | { "M", 1048576 },
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| 30 | { "GD", 1000000000 },
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| 31 | { "G", 1073741824 },
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| 32 | { "", 0 }
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| 33 | };
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| 34 |
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| 35 | struct globals {
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| 36 | off_t out_full, out_part, in_full, in_part;
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| 37 | #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
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| 38 | unsigned long long total_bytes;
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| 39 | unsigned long long begin_time_us;
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| 40 | #endif
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| 41 | } FIX_ALIASING;
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| 42 | #define G (*(struct globals*)&bb_common_bufsiz1)
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| 43 | #define INIT_G() do { \
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| 44 | /* we have to zero it out because of NOEXEC */ \
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| 45 | memset(&G, 0, sizeof(G)); \
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| 46 | } while (0)
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| 47 |
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| 48 |
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| 49 | static void dd_output_status(int UNUSED_PARAM cur_signal)
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| 50 | {
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| 51 | #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
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| 52 | double seconds;
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| 53 | unsigned long long bytes_sec;
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| 54 | unsigned long long now_us = monotonic_us(); /* before fprintf */
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| 55 | #endif
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| 56 |
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| 57 | /* Deliberately using %u, not %d */
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| 58 | fprintf(stderr, "%"OFF_FMT"u+%"OFF_FMT"u records in\n"
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| 59 | "%"OFF_FMT"u+%"OFF_FMT"u records out\n",
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| 60 | G.in_full, G.in_part,
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| 61 | G.out_full, G.out_part);
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| 62 |
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| 63 | #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
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| 64 | fprintf(stderr, "%llu bytes (%sB) copied, ",
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| 65 | G.total_bytes,
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| 66 | /* show fractional digit, use suffixes */
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| 67 | make_human_readable_str(G.total_bytes, 1, 0)
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| 68 | );
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| 69 | /* Corner cases:
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| 70 | * ./busybox dd </dev/null >/dev/null
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| 71 | * ./busybox dd bs=1M count=2000 </dev/zero >/dev/null
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| 72 | * (echo DONE) | ./busybox dd >/dev/null
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| 73 | * (sleep 1; echo DONE) | ./busybox dd >/dev/null
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| 74 | */
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| 75 | seconds = (now_us - G.begin_time_us) / 1000000.0;
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| 76 | bytes_sec = G.total_bytes / seconds;
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| 77 | fprintf(stderr, "%f seconds, %sB/s\n",
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| 78 | seconds,
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| 79 | /* show fractional digit, use suffixes */
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| 80 | make_human_readable_str(bytes_sec, 1, 0)
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| 81 | );
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| 82 | #endif
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| 83 | }
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| 84 |
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| 85 | static ssize_t full_write_or_warn(const void *buf, size_t len,
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| 86 | const char *const filename)
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| 87 | {
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| 88 | ssize_t n = full_write(ofd, buf, len);
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| 89 | if (n < 0)
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| 90 | bb_perror_msg("writing '%s'", filename);
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| 91 | return n;
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| 92 | }
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| 93 |
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| 94 | static bool write_and_stats(const void *buf, size_t len, size_t obs,
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| 95 | const char *filename)
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| 96 | {
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| 97 | ssize_t n = full_write_or_warn(buf, len, filename);
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| 98 | if (n < 0)
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| 99 | return 1;
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| 100 | if ((size_t)n == obs)
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| 101 | G.out_full++;
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| 102 | else if (n) /* > 0 */
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| 103 | G.out_part++;
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| 104 | #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
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| 105 | G.total_bytes += n;
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| 106 | #endif
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| 107 | return 0;
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| 108 | }
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| 109 |
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| 110 | #if ENABLE_LFS
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| 111 | # define XATOU_SFX xatoull_sfx
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| 112 | #else
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| 113 | # define XATOU_SFX xatoul_sfx
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| 114 | #endif
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| 115 |
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| 116 | int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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| 117 | int dd_main(int argc UNUSED_PARAM, char **argv)
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| 118 | {
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| 119 | enum {
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| 120 | /* Must be in the same order as OP_conv_XXX! */
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| 121 | /* (see "flags |= (1 << what)" below) */
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| 122 | FLAG_NOTRUNC = 1 << 0,
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| 123 | FLAG_SYNC = 1 << 1,
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| 124 | FLAG_NOERROR = 1 << 2,
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| 125 | FLAG_FSYNC = 1 << 3,
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| 126 | /* end of conv flags */
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| 127 | FLAG_TWOBUFS = 1 << 4,
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| 128 | FLAG_COUNT = 1 << 5,
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| 129 | };
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| 130 | static const char keywords[] ALIGN1 =
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| 131 | "bs\0""count\0""seek\0""skip\0""if\0""of\0"
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| 132 | #if ENABLE_FEATURE_DD_IBS_OBS
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| 133 | "ibs\0""obs\0""conv\0"
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| 134 | #endif
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| 135 | ;
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| 136 | #if ENABLE_FEATURE_DD_IBS_OBS
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| 137 | static const char conv_words[] ALIGN1 =
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| 138 | "notrunc\0""sync\0""noerror\0""fsync\0";
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| 139 | #endif
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| 140 | enum {
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| 141 | OP_bs = 0,
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| 142 | OP_count,
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| 143 | OP_seek,
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| 144 | OP_skip,
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| 145 | OP_if,
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| 146 | OP_of,
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| 147 | #if ENABLE_FEATURE_DD_IBS_OBS
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| 148 | OP_ibs,
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| 149 | OP_obs,
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| 150 | OP_conv,
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| 151 | /* Must be in the same order as FLAG_XXX! */
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| 152 | OP_conv_notrunc = 0,
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| 153 | OP_conv_sync,
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| 154 | OP_conv_noerror,
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| 155 | OP_conv_fsync,
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| 156 | /* Unimplemented conv=XXX: */
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| 157 | //nocreat do not create the output file
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| 158 | //excl fail if the output file already exists
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| 159 | //fdatasync physically write output file data before finishing
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| 160 | //swab swap every pair of input bytes
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| 161 | //lcase change upper case to lower case
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| 162 | //ucase change lower case to upper case
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| 163 | //block pad newline-terminated records with spaces to cbs-size
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| 164 | //unblock replace trailing spaces in cbs-size records with newline
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| 165 | //ascii from EBCDIC to ASCII
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| 166 | //ebcdic from ASCII to EBCDIC
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| 167 | //ibm from ASCII to alternate EBCDIC
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| 168 | #endif
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| 169 | };
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| 170 | int exitcode = EXIT_FAILURE;
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| 171 | size_t ibs = 512, obs = 512;
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| 172 | ssize_t n, w;
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| 173 | char *ibuf, *obuf;
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| 174 | /* And these are all zeroed at once! */
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| 175 | struct {
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| 176 | int flags;
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| 177 | size_t oc;
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| 178 | off_t count;
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| 179 | off_t seek, skip;
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| 180 | const char *infile, *outfile;
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| 181 | } Z;
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| 182 | #define flags (Z.flags )
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| 183 | #define oc (Z.oc )
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| 184 | #define count (Z.count )
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| 185 | #define seek (Z.seek )
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| 186 | #define skip (Z.skip )
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| 187 | #define infile (Z.infile )
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| 188 | #define outfile (Z.outfile)
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| 189 |
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| 190 | memset(&Z, 0, sizeof(Z));
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| 191 | INIT_G();
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| 192 | //fflush_all(); - is this needed because of NOEXEC?
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| 193 |
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| 194 | for (n = 1; argv[n]; n++) {
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| 195 | int what;
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| 196 | char *val;
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| 197 | char *arg = argv[n];
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| 198 |
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| 199 | #if ENABLE_DESKTOP
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| 200 | /* "dd --". NB: coreutils 6.9 will complain if they see
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| 201 | * more than one of them. We wouldn't. */
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| 202 | if (arg[0] == '-' && arg[1] == '-' && arg[2] == '\0')
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| 203 | continue;
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| 204 | #endif
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| 205 | val = strchr(arg, '=');
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| 206 | if (val == NULL)
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| 207 | bb_show_usage();
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| 208 | *val = '\0';
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| 209 | what = index_in_strings(keywords, arg);
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| 210 | if (what < 0)
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| 211 | bb_show_usage();
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| 212 | /* *val = '='; - to preserve ps listing? */
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| 213 | val++;
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| 214 | #if ENABLE_FEATURE_DD_IBS_OBS
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| 215 | if (what == OP_ibs) {
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| 216 | /* Must fit into positive ssize_t */
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| 217 | ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
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| 218 | /*continue;*/
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| 219 | }
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| 220 | if (what == OP_obs) {
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| 221 | obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
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| 222 | /*continue;*/
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| 223 | }
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| 224 | if (what == OP_conv) {
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| 225 | while (1) {
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| 226 | /* find ',', replace them with NUL so we can use val for
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| 227 | * index_in_strings() without copying.
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| 228 | * We rely on val being non-null, else strchr would fault.
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| 229 | */
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| 230 | arg = strchr(val, ',');
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| 231 | if (arg)
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| 232 | *arg = '\0';
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| 233 | what = index_in_strings(conv_words, val);
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| 234 | if (what < 0)
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| 235 | bb_error_msg_and_die(bb_msg_invalid_arg, val, "conv");
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| 236 | flags |= (1 << what);
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| 237 | if (!arg) /* no ',' left, so this was the last specifier */
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| 238 | break;
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| 239 | /* *arg = ','; - to preserve ps listing? */
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| 240 | val = arg + 1; /* skip this keyword and ',' */
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| 241 | }
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| 242 | continue; /* we trashed 'what', can't fall through */
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| 243 | }
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| 244 | #endif
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| 245 | if (what == OP_bs) {
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| 246 | ibs = obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
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| 247 | /*continue;*/
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| 248 | }
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| 249 | /* These can be large: */
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| 250 | if (what == OP_count) {
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| 251 | flags |= FLAG_COUNT;
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| 252 | count = XATOU_SFX(val, dd_suffixes);
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| 253 | /*continue;*/
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| 254 | }
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| 255 | if (what == OP_seek) {
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| 256 | seek = XATOU_SFX(val, dd_suffixes);
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| 257 | /*continue;*/
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| 258 | }
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| 259 | if (what == OP_skip) {
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| 260 | skip = XATOU_SFX(val, dd_suffixes);
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| 261 | /*continue;*/
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| 262 | }
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| 263 | if (what == OP_if) {
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| 264 | infile = val;
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| 265 | /*continue;*/
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| 266 | }
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| 267 | if (what == OP_of) {
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| 268 | outfile = val;
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| 269 | /*continue;*/
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| 270 | }
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| 271 | } /* end of "for (argv[n])" */
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| 272 |
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| 273 | //XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
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| 274 | ibuf = obuf = xmalloc(ibs);
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| 275 | if (ibs != obs) {
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| 276 | flags |= FLAG_TWOBUFS;
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| 277 | obuf = xmalloc(obs);
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| 278 | }
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| 279 |
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| 280 | #if ENABLE_FEATURE_DD_SIGNAL_HANDLING
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| 281 | signal_SA_RESTART_empty_mask(SIGUSR1, dd_output_status);
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| 282 | #endif
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| 283 | #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
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| 284 | G.begin_time_us = monotonic_us();
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| 285 | #endif
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| 286 |
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| 287 | if (infile != NULL)
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| 288 | xmove_fd(xopen(infile, O_RDONLY), ifd);
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| 289 | else {
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| 290 | infile = bb_msg_standard_input;
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| 291 | }
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| 292 | if (outfile != NULL) {
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| 293 | int oflag = O_WRONLY | O_CREAT;
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| 294 |
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| 295 | if (!seek && !(flags & FLAG_NOTRUNC))
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| 296 | oflag |= O_TRUNC;
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| 297 |
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| 298 | xmove_fd(xopen(outfile, oflag), ofd);
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| 299 |
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| 300 | if (seek && !(flags & FLAG_NOTRUNC)) {
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| 301 | if (ftruncate(ofd, seek * obs) < 0) {
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| 302 | struct stat st;
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| 303 |
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| 304 | if (fstat(ofd, &st) < 0
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| 305 | || S_ISREG(st.st_mode)
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| 306 | || S_ISDIR(st.st_mode)
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| 307 | ) {
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| 308 | goto die_outfile;
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| 309 | }
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| 310 | }
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| 311 | }
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| 312 | } else {
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| 313 | outfile = bb_msg_standard_output;
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| 314 | }
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| 315 | if (skip) {
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| 316 | if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
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| 317 | while (skip-- > 0) {
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| 318 | n = safe_read(ifd, ibuf, ibs);
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| 319 | if (n < 0)
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| 320 | goto die_infile;
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| 321 | if (n == 0)
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| 322 | break;
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| 323 | }
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| 324 | }
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| 325 | }
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| 326 | if (seek) {
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| 327 | if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
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| 328 | goto die_outfile;
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| 329 | }
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| 330 |
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| 331 | while (!(flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
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| 332 | n = safe_read(ifd, ibuf, ibs);
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| 333 | if (n == 0)
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| 334 | break;
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| 335 | if (n < 0) {
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| 336 | /* "Bad block" */
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| 337 | if (!(flags & FLAG_NOERROR))
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| 338 | goto die_infile;
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| 339 | bb_simple_perror_msg(infile);
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| 340 | /* GNU dd with conv=noerror skips over bad blocks */
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| 341 | xlseek(ifd, ibs, SEEK_CUR);
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| 342 | /* conv=noerror,sync writes NULs,
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| 343 | * conv=noerror just ignores input bad blocks */
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| 344 | n = 0;
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| 345 | }
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| 346 | if ((size_t)n == ibs)
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| 347 | G.in_full++;
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| 348 | else {
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| 349 | G.in_part++;
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| 350 | if (flags & FLAG_SYNC) {
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| 351 | memset(ibuf + n, 0, ibs - n);
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| 352 | n = ibs;
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| 353 | }
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| 354 | }
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| 355 | if (flags & FLAG_TWOBUFS) {
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| 356 | char *tmp = ibuf;
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| 357 | while (n) {
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| 358 | size_t d = obs - oc;
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| 359 |
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| 360 | if (d > (size_t)n)
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| 361 | d = n;
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| 362 | memcpy(obuf + oc, tmp, d);
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| 363 | n -= d;
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| 364 | tmp += d;
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| 365 | oc += d;
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| 366 | if (oc == obs) {
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| 367 | if (write_and_stats(obuf, obs, obs, outfile))
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| 368 | goto out_status;
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| 369 | oc = 0;
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| 370 | }
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| 371 | }
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| 372 | } else if (write_and_stats(ibuf, n, obs, outfile))
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| 373 | goto out_status;
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| 374 |
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| 375 | if (flags & FLAG_FSYNC) {
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| 376 | if (fsync(ofd) < 0)
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| 377 | goto die_outfile;
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| 378 | }
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| 379 | }
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| 380 |
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| 381 | if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
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| 382 | w = full_write_or_warn(obuf, oc, outfile);
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| 383 | if (w < 0) goto out_status;
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| 384 | if (w > 0) G.out_part++;
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| 385 | }
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| 386 | if (close(ifd) < 0) {
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| 387 | die_infile:
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| 388 | bb_simple_perror_msg_and_die(infile);
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| 389 | }
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| 390 |
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| 391 | if (close(ofd) < 0) {
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| 392 | die_outfile:
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| 393 | bb_simple_perror_msg_and_die(outfile);
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| 394 | }
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| 395 |
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| 396 | exitcode = EXIT_SUCCESS;
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| 397 | out_status:
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| 398 | dd_output_status(0);
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| 399 |
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| 400 | return exitcode;
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| 401 | }
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