[821] | 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 tarball for details.
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| 9 | */
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| 10 |
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[1765] | 11 | #include <signal.h> /* For FEATURE_DD_SIGNAL_HANDLING */
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| 12 | #include "libbb.h"
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[821] | 13 |
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[1765] | 14 | /* This is a NOEXEC applet. Be very careful! */
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| 15 |
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| 16 |
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[821] | 17 | static const struct suffix_mult dd_suffixes[] = {
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| 18 | { "c", 1 },
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| 19 | { "w", 2 },
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| 20 | { "b", 512 },
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| 21 | { "kD", 1000 },
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| 22 | { "k", 1024 },
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[1765] | 23 | { "K", 1024 }, /* compat with coreutils dd */
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[821] | 24 | { "MD", 1000000 },
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| 25 | { "M", 1048576 },
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| 26 | { "GD", 1000000000 },
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| 27 | { "G", 1073741824 },
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[1765] | 28 | { }
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[821] | 29 | };
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| 30 |
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[1765] | 31 | struct globals {
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| 32 | off_t out_full, out_part, in_full, in_part;
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| 33 | };
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| 34 | #define G (*(struct globals*)&bb_common_bufsiz1)
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| 35 | /* We have to zero it out because of NOEXEC */
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| 36 | #define INIT_G() memset(&G, 0, sizeof(G))
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[821] | 37 |
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[1765] | 38 |
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| 39 | static void dd_output_status(int ATTRIBUTE_UNUSED cur_signal)
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[821] | 40 | {
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[1765] | 41 | /* Deliberately using %u, not %d */
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| 42 | fprintf(stderr, "%"OFF_FMT"u+%"OFF_FMT"u records in\n"
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| 43 | "%"OFF_FMT"u+%"OFF_FMT"u records out\n",
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| 44 | G.in_full, G.in_part,
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| 45 | G.out_full, G.out_part);
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[821] | 46 | }
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| 47 |
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[1765] | 48 | static ssize_t full_write_or_warn(int fd, const void *buf, size_t len,
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| 49 | const char *const filename)
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| 50 | {
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| 51 | ssize_t n = full_write(fd, buf, len);
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| 52 | if (n < 0)
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| 53 | bb_perror_msg("writing '%s'", filename);
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| 54 | return n;
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| 55 | }
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| 56 |
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| 57 | static bool write_and_stats(int fd, const void *buf, size_t len, size_t obs,
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| 58 | const char *filename)
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| 59 | {
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| 60 | ssize_t n = full_write_or_warn(fd, buf, len, filename);
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| 61 | if (n < 0)
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| 62 | return 1;
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| 63 | if (n == obs)
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| 64 | G.out_full++;
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| 65 | else if (n) /* > 0 */
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| 66 | G.out_part++;
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| 67 | return 0;
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| 68 | }
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| 69 |
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| 70 | #if ENABLE_LFS
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| 71 | #define XATOU_SFX xatoull_sfx
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| 72 | #else
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| 73 | #define XATOU_SFX xatoul_sfx
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| 74 | #endif
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| 75 |
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| 76 | int dd_main(int argc, char **argv);
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[821] | 77 | int dd_main(int argc, char **argv)
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| 78 | {
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[1765] | 79 | enum {
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| 80 | FLAG_SYNC = 1 << 0,
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| 81 | FLAG_NOERROR = 1 << 1,
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| 82 | FLAG_NOTRUNC = 1 << 2,
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| 83 | FLAG_TWOBUFS = 1 << 3,
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| 84 | FLAG_COUNT = 1 << 4,
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| 85 | };
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| 86 | static const char keywords[] ALIGN1 =
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| 87 | "bs=\0""count=\0""seek=\0""skip=\0""if=\0""of=\0"
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| 88 | #if ENABLE_FEATURE_DD_IBS_OBS
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| 89 | "ibs=\0""obs=\0""conv=\0""notrunc\0""sync\0""noerror\0"
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| 90 | #endif
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| 91 | ;
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| 92 | enum {
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| 93 | OP_bs = 1,
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| 94 | OP_count,
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| 95 | OP_seek,
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| 96 | OP_skip,
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| 97 | OP_if,
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| 98 | OP_of,
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| 99 | #if ENABLE_FEATURE_DD_IBS_OBS
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| 100 | OP_ibs,
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| 101 | OP_obs,
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| 102 | OP_conv,
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| 103 | OP_conv_notrunc,
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| 104 | OP_conv_sync,
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| 105 | OP_conv_noerror,
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| 106 | #endif
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| 107 | };
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| 108 | size_t ibs = 512, obs = 512;
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| 109 | ssize_t n, w;
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[821] | 110 | char *ibuf, *obuf;
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[1765] | 111 | /* And these are all zeroed at once! */
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| 112 | struct {
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| 113 | int flags;
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| 114 | int ifd, ofd;
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| 115 | size_t oc;
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| 116 | off_t count;
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| 117 | off_t seek, skip;
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| 118 | const char *infile, *outfile;
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| 119 | #if ENABLE_FEATURE_DD_SIGNAL_HANDLING
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| 120 | struct sigaction sigact;
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| 121 | #endif
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| 122 | } Z;
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| 123 | #define flags (Z.flags )
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| 124 | #define ifd (Z.ifd )
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| 125 | #define ofd (Z.ofd )
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| 126 | #define oc (Z.oc )
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| 127 | #define count (Z.count )
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| 128 | #define seek (Z.seek )
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| 129 | #define skip (Z.skip )
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| 130 | #define infile (Z.infile )
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| 131 | #define outfile (Z.outfile)
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| 132 | #define sigact (Z.sigact )
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[821] | 133 |
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[1765] | 134 | memset(&Z, 0, sizeof(Z));
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| 135 | INIT_G();
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[821] | 136 |
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[1765] | 137 | #if ENABLE_FEATURE_DD_SIGNAL_HANDLING
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| 138 | sigact.sa_handler = dd_output_status;
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| 139 | sigact.sa_flags = SA_RESTART;
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| 140 | sigemptyset(&sigact.sa_mask);
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| 141 | sigaction(SIGUSR1, &sigact, NULL);
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| 142 | #endif
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[821] | 143 |
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[1765] | 144 | for (n = 1; n < argc; n++) {
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| 145 | smalluint key_len;
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| 146 | smalluint what;
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| 147 | char *key;
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| 148 | char *arg = argv[n];
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| 149 |
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| 150 | //XXX:FIXME: we reject plain "dd --" This would cost ~20 bytes, so..
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| 151 | //if (*arg == '-' && *++arg == '-' && !*++arg) continue;
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| 152 | key = strstr(arg, "=");
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| 153 | if (key == NULL)
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| 154 | bb_show_usage();
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| 155 | key_len = key - arg + 1;
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| 156 | key = xstrndup(arg, key_len);
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| 157 | what = index_in_strings(keywords, key) + 1;
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| 158 | if (ENABLE_FEATURE_CLEAN_UP)
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| 159 | free(key);
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| 160 | if (what == 0)
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| 161 | bb_show_usage();
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| 162 | arg += key_len;
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| 163 | /* Must fit into positive ssize_t */
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| 164 | #if ENABLE_FEATURE_DD_IBS_OBS
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| 165 | if (what == OP_ibs) {
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| 166 | ibs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
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| 167 | continue;
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| 168 | }
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| 169 | if (what == OP_obs) {
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| 170 | obs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
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| 171 | continue;
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| 172 | }
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| 173 | if (what == OP_conv) {
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| 174 | while (1) {
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| 175 | /* find ',', replace them with nil so we can use arg for
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| 176 | * index_in_strings() without copying.
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| 177 | * We rely on arg being non-null, else strchr would fault.
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| 178 | */
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| 179 | key = strchr(arg, ',');
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| 180 | if (key)
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| 181 | *key = '\0';
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| 182 | what = index_in_strings(keywords, arg) + 1;
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| 183 | if (what < OP_conv_notrunc)
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| 184 | bb_error_msg_and_die(bb_msg_invalid_arg, arg, "conv");
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| 185 | if (what == OP_conv_notrunc)
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| 186 | flags |= FLAG_NOTRUNC;
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| 187 | if (what == OP_conv_sync)
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| 188 | flags |= FLAG_SYNC;
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| 189 | if (what == OP_conv_noerror)
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| 190 | flags |= FLAG_NOERROR;
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| 191 | if (!key) /* no ',' left, so this was the last specifier */
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| 192 | break;
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| 193 | arg = key + 1; /* skip this keyword and ',' */
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[821] | 194 | }
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[1765] | 195 | continue;
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[821] | 196 | }
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[1765] | 197 | #endif
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| 198 | if (what == OP_bs) {
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| 199 | ibs = obs = xatoul_range_sfx(arg, 1, ((size_t)-1L)/2, dd_suffixes);
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| 200 | continue;
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| 201 | }
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| 202 | /* These can be large: */
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| 203 | if (what == OP_count) {
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| 204 | flags |= FLAG_COUNT;
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| 205 | count = XATOU_SFX(arg, dd_suffixes);
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| 206 | continue;
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| 207 | }
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| 208 | if (what == OP_seek) {
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| 209 | seek = XATOU_SFX(arg, dd_suffixes);
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| 210 | continue;
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| 211 | }
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| 212 | if (what == OP_skip) {
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| 213 | skip = XATOU_SFX(arg, dd_suffixes);
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| 214 | continue;
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| 215 | }
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| 216 | if (what == OP_if) {
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| 217 | infile = arg;
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| 218 | continue;
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| 219 | }
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| 220 | if (what == OP_of)
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| 221 | outfile = arg;
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[821] | 222 | }
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[1765] | 223 | //XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
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| 224 | ibuf = obuf = xmalloc(ibs);
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| 225 | if (ibs != obs) {
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| 226 | flags |= FLAG_TWOBUFS;
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| 227 | obuf = xmalloc(obs);
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| 228 | }
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| 229 | if (infile != NULL)
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| 230 | ifd = xopen(infile, O_RDONLY);
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| 231 | else {
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| 232 | /* ifd = STDIN_FILENO; - it's zero and it's already there */
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[821] | 233 | infile = bb_msg_standard_input;
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| 234 | }
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| 235 | if (outfile != NULL) {
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[1765] | 236 | int oflag = O_WRONLY | O_CREAT;
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[821] | 237 |
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[1765] | 238 | if (!seek && !(flags & FLAG_NOTRUNC))
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[821] | 239 | oflag |= O_TRUNC;
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| 240 |
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[1765] | 241 | ofd = xopen(outfile, oflag);
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[821] | 242 |
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[1765] | 243 | if (seek && !(flags & FLAG_NOTRUNC)) {
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[821] | 244 | if (ftruncate(ofd, seek * obs) < 0) {
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| 245 | struct stat st;
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| 246 |
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[1765] | 247 | if (fstat(ofd, &st) < 0 || S_ISREG(st.st_mode) ||
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| 248 | S_ISDIR(st.st_mode))
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| 249 | goto die_outfile;
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[821] | 250 | }
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| 251 | }
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| 252 | } else {
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| 253 | ofd = STDOUT_FILENO;
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| 254 | outfile = bb_msg_standard_output;
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| 255 | }
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| 256 | if (skip) {
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| 257 | if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
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| 258 | while (skip-- > 0) {
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| 259 | n = safe_read(ifd, ibuf, ibs);
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| 260 | if (n < 0)
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[1765] | 261 | goto die_infile;
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[821] | 262 | if (n == 0)
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| 263 | break;
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| 264 | }
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| 265 | }
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| 266 | }
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| 267 | if (seek) {
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[1765] | 268 | if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
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| 269 | goto die_outfile;
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[821] | 270 | }
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| 271 |
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[1765] | 272 | while (!(flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
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| 273 | if (flags & FLAG_NOERROR) /* Pre-zero the buffer if conv=noerror */
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| 274 | memset(ibuf, 0, ibs);
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[821] | 275 | n = safe_read(ifd, ibuf, ibs);
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[1765] | 276 | if (n == 0)
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[821] | 277 | break;
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| 278 | if (n < 0) {
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[1765] | 279 | if (flags & FLAG_NOERROR) {
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[821] | 280 | n = ibs;
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| 281 | bb_perror_msg("%s", infile);
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[1765] | 282 | } else
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| 283 | goto die_infile;
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[821] | 284 | }
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[1765] | 285 | if ((size_t)n == ibs)
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| 286 | G.in_full++;
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| 287 | else {
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| 288 | G.in_part++;
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| 289 | if (flags & FLAG_SYNC) {
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[821] | 290 | memset(ibuf + n, '\0', ibs - n);
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| 291 | n = ibs;
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| 292 | }
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| 293 | }
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[1765] | 294 | if (flags & FLAG_TWOBUFS) {
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[821] | 295 | char *tmp = ibuf;
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| 296 | while (n) {
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| 297 | size_t d = obs - oc;
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| 298 |
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[1765] | 299 | if (d > n)
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| 300 | d = n;
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[821] | 301 | memcpy(obuf + oc, tmp, d);
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| 302 | n -= d;
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| 303 | tmp += d;
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| 304 | oc += d;
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| 305 | if (oc == obs) {
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[1765] | 306 | if (write_and_stats(ofd, obuf, obs, obs, outfile))
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| 307 | goto out_status;
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[821] | 308 | oc = 0;
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| 309 | }
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| 310 | }
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[1765] | 311 | } else if (write_and_stats(ofd, ibuf, n, obs, outfile))
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| 312 | goto out_status;
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[821] | 313 | }
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[1765] | 314 |
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[821] | 315 | if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
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[1765] | 316 | w = full_write_or_warn(ofd, obuf, oc, outfile);
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| 317 | if (w < 0) goto out_status;
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| 318 | if (w > 0)
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| 319 | G.out_part++;
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[821] | 320 | }
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[1765] | 321 | if (close(ifd) < 0) {
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| 322 | die_infile:
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[821] | 323 | bb_perror_msg_and_die("%s", infile);
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| 324 | }
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| 325 |
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[1765] | 326 | if (close(ofd) < 0) {
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| 327 | die_outfile:
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[821] | 328 | bb_perror_msg_and_die("%s", outfile);
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| 329 | }
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[1765] | 330 | out_status:
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[821] | 331 | dd_output_status(0);
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| 332 |
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| 333 | return EXIT_SUCCESS;
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| 334 | }
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