sulogin: use bb_error_msg instead of bb_info_msg; better message
[oweals/busybox.git] / coreutils / dd.c
index 9973a145b4e0e7a97337b74c682ba39fbbbd59d6..0c0ea07b95bc5bcc0c943c1a1962cc80a5fbc1d0 100644 (file)
@@ -8,6 +8,88 @@
  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
+//config:config DD
+//config:      bool "dd"
+//config:      default y
+//config:      help
+//config:        dd copies a file (from standard input to standard output,
+//config:        by default) using specific input and output blocksizes,
+//config:        while optionally performing conversions on it.
+//config:
+//config:config FEATURE_DD_SIGNAL_HANDLING
+//config:      bool "Enable signal handling for status reporting"
+//config:      default y
+//config:      depends on DD
+//config:      help
+//config:        Sending a SIGUSR1 signal to a running `dd' process makes it
+//config:        print to standard error the number of records read and written
+//config:        so far, then to resume copying.
+//config:
+//config:        $ dd if=/dev/zero of=/dev/null &
+//config:        $ pid=$!; kill -USR1 $pid; sleep 1; kill $pid
+//config:        10899206+0 records in
+//config:        10899206+0 records out
+//config:
+//config:config FEATURE_DD_THIRD_STATUS_LINE
+//config:      bool "Enable the third status line upon signal"
+//config:      default y
+//config:      depends on DD && FEATURE_DD_SIGNAL_HANDLING
+//config:      help
+//config:        Displays a coreutils-like third status line with transferred bytes,
+//config:        elapsed time and speed.
+//config:
+//config:config FEATURE_DD_IBS_OBS
+//config:      bool "Enable ibs, obs and conv options"
+//config:      default y
+//config:      depends on DD
+//config:      help
+//config:        Enables support for writing a certain number of bytes in and out,
+//config:        at a time, and performing conversions on the data stream.
+//config:
+//config:config FEATURE_DD_STATUS
+//config:      bool "Enable status display options"
+//config:      default y
+//config:      depends on DD
+//config:      help
+//config:        Enables support for status=noxfer/none option.
+
+//usage:#define dd_trivial_usage
+//usage:       "[if=FILE] [of=FILE] " IF_FEATURE_DD_IBS_OBS("[ibs=N] [obs=N] ") "[bs=N] [count=N] [skip=N]\n"
+//usage:       "       [seek=N]" IF_FEATURE_DD_IBS_OBS(" [conv=notrunc|noerror|sync|fsync] [iflag=skip_bytes]")
+//usage:#define dd_full_usage "\n\n"
+//usage:       "Copy a file with converting and formatting\n"
+//usage:     "\n       if=FILE         Read from FILE instead of stdin"
+//usage:     "\n       of=FILE         Write to FILE instead of stdout"
+//usage:     "\n       bs=N            Read and write N bytes at a time"
+//usage:       IF_FEATURE_DD_IBS_OBS(
+//usage:     "\n       ibs=N           Read N bytes at a time"
+//usage:       )
+//usage:       IF_FEATURE_DD_IBS_OBS(
+//usage:     "\n       obs=N           Write N bytes at a time"
+//usage:       )
+//usage:     "\n       count=N         Copy only N input blocks"
+//usage:     "\n       skip=N          Skip N input blocks"
+//usage:     "\n       seek=N          Skip N output blocks"
+//usage:       IF_FEATURE_DD_IBS_OBS(
+//usage:     "\n       conv=notrunc    Don't truncate output file"
+//usage:     "\n       conv=noerror    Continue after read errors"
+//usage:     "\n       conv=sync       Pad blocks with zeros"
+//usage:     "\n       conv=fsync      Physically write data out before finishing"
+//usage:     "\n       conv=swab       Swap every pair of bytes"
+//usage:     "\n       iflag=skip_bytes        skip=N is in bytes"
+//usage:       )
+//usage:       IF_FEATURE_DD_STATUS(
+//usage:     "\n       status=noxfer   Suppress rate output"
+//usage:     "\n       status=none     Suppress all output"
+//usage:       )
+//usage:     "\n"
+//usage:     "\nN may be suffixed by c (1), w (2), b (512), kB (1000), k (1024), MB, M, GB, G"
+//usage:
+//usage:#define dd_example_usage
+//usage:       "$ dd if=/dev/zero of=/dev/ram1 bs=1M count=4\n"
+//usage:       "4+0 records in\n"
+//usage:       "4+0 records out\n"
+
 #include "libbb.h"
 
 /* This is a NOEXEC applet. Be very careful! */
@@ -18,26 +100,13 @@ enum {
        ofd = STDOUT_FILENO,
 };
 
-static const struct suffix_mult dd_suffixes[] = {
-       { "c", 1 },
-       { "w", 2 },
-       { "b", 512 },
-       { "kD", 1000 },
-       { "k", 1024 },
-       { "K", 1024 },  /* compat with coreutils dd */
-       { "MD", 1000000 },
-       { "M", 1048576 },
-       { "GD", 1000000000 },
-       { "G", 1073741824 },
-       { "", 0 }
-};
-
 struct globals {
        off_t out_full, out_part, in_full, in_part;
 #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
        unsigned long long total_bytes;
        unsigned long long begin_time_us;
 #endif
+       int flags;
 } FIX_ALIASING;
 #define G (*(struct globals*)&bb_common_bufsiz1)
 #define INIT_G() do { \
@@ -45,6 +114,25 @@ struct globals {
        memset(&G, 0, sizeof(G)); \
 } while (0)
 
+enum {
+       /* Must be in the same order as OP_conv_XXX! */
+       /* (see "flags |= (1 << what)" below) */
+       FLAG_NOTRUNC = (1 << 0) * ENABLE_FEATURE_DD_IBS_OBS,
+       FLAG_SYNC    = (1 << 1) * ENABLE_FEATURE_DD_IBS_OBS,
+       FLAG_NOERROR = (1 << 2) * ENABLE_FEATURE_DD_IBS_OBS,
+       FLAG_FSYNC   = (1 << 3) * ENABLE_FEATURE_DD_IBS_OBS,
+       FLAG_SWAB    = (1 << 4) * ENABLE_FEATURE_DD_IBS_OBS,
+       /* end of conv flags */
+       /* start of input flags */
+       FLAG_IFLAG_SHIFT = 5,
+       FLAG_SKIP_BYTES = (1 << 5) * ENABLE_FEATURE_DD_IBS_OBS,
+       /* end of input flags */
+       FLAG_TWOBUFS = (1 << 6) * ENABLE_FEATURE_DD_IBS_OBS,
+       FLAG_COUNT   = 1 << 7,
+       FLAG_STATUS  = 1 << 8,
+       FLAG_STATUS_NONE = 1 << 9,
+       FLAG_STATUS_NOXFER = 1 << 10,
+};
 
 static void dd_output_status(int UNUSED_PARAM cur_signal)
 {
@@ -61,6 +149,13 @@ static void dd_output_status(int UNUSED_PARAM cur_signal)
                        G.out_full, G.out_part);
 
 #if ENABLE_FEATURE_DD_THIRD_STATUS_LINE
+# if ENABLE_FEATURE_DD_STATUS
+       if (G.flags & FLAG_STATUS_NOXFER) /* status=noxfer active? */
+               return;
+       //TODO: should status=none make dd stop reacting to USR1 entirely?
+       //So far we react to it (we print the stats),
+       //status=none only suppresses final, non-USR1 generated status message.
+# endif
        fprintf(stderr, "%llu bytes (%sB) copied, ",
                        G.total_bytes,
                        /* show fractional digit, use suffixes */
@@ -113,29 +208,51 @@ static bool write_and_stats(const void *buf, size_t len, size_t obs,
 # define XATOU_SFX xatoul_sfx
 #endif
 
+#if ENABLE_FEATURE_DD_IBS_OBS
+static int parse_comma_flags(char *val, const char *words, const char *error_in)
+{
+       int flags = 0;
+       while (1) {
+               int n;
+               char *arg;
+               /* find ',', replace them with NUL so we can use val for
+                * index_in_strings() without copying.
+                * We rely on val being non-null, else strchr would fault.
+                */
+               arg = strchr(val, ',');
+               if (arg)
+                       *arg = '\0';
+               n = index_in_strings(words, val);
+               if (n < 0)
+                       bb_error_msg_and_die(bb_msg_invalid_arg_to, val, error_in);
+               flags |= (1 << n);
+               if (!arg) /* no ',' left, so this was the last specifier */
+                       break;
+               *arg = ','; /* to preserve ps listing */
+               val = arg + 1; /* skip this keyword and ',' */
+       }
+       return flags;
+}
+#endif
+
 int dd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int dd_main(int argc UNUSED_PARAM, char **argv)
 {
-       enum {
-               /* Must be in the same order as OP_conv_XXX! */
-               /* (see "flags |= (1 << what)" below) */
-               FLAG_NOTRUNC = 1 << 0,
-               FLAG_SYNC    = 1 << 1,
-               FLAG_NOERROR = 1 << 2,
-               FLAG_FSYNC   = 1 << 3,
-               /* end of conv flags */
-               FLAG_TWOBUFS = 1 << 4,
-               FLAG_COUNT   = 1 << 5,
-       };
        static const char keywords[] ALIGN1 =
-               "bs\0""count\0""seek\0""skip\0""if\0""of\0"
+               "bs\0""count\0""seek\0""skip\0""if\0""of\0"IF_FEATURE_DD_STATUS("status\0")
 #if ENABLE_FEATURE_DD_IBS_OBS
-               "ibs\0""obs\0""conv\0"
+               "ibs\0""obs\0""conv\0""iflag\0"
 #endif
                ;
 #if ENABLE_FEATURE_DD_IBS_OBS
        static const char conv_words[] ALIGN1 =
-               "notrunc\0""sync\0""noerror\0""fsync\0";
+               "notrunc\0""sync\0""noerror\0""fsync\0""swab\0";
+       static const char iflag_words[] ALIGN1 =
+               "skip_bytes\0";
+#endif
+#if ENABLE_FEATURE_DD_STATUS
+       static const char status_words[] ALIGN1 =
+               "none\0""noxfer\0";
 #endif
        enum {
                OP_bs = 0,
@@ -144,20 +261,22 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
                OP_skip,
                OP_if,
                OP_of,
+               IF_FEATURE_DD_STATUS(OP_status,)
 #if ENABLE_FEATURE_DD_IBS_OBS
                OP_ibs,
                OP_obs,
                OP_conv,
+               OP_iflag,
                /* Must be in the same order as FLAG_XXX! */
                OP_conv_notrunc = 0,
                OP_conv_sync,
                OP_conv_noerror,
                OP_conv_fsync,
+               OP_conv_swab,
        /* Unimplemented conv=XXX: */
        //nocreat       do not create the output file
        //excl          fail if the output file already exists
        //fdatasync     physically write output file data before finishing
-       //swab          swap every pair of input bytes
        //lcase         change upper case to lower case
        //ucase         change lower case to upper case
        //block         pad newline-terminated records with spaces to cbs-size
@@ -165,22 +284,32 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
        //ascii         from EBCDIC to ASCII
        //ebcdic        from ASCII to EBCDIC
        //ibm           from ASCII to alternate EBCDIC
+       /* Partially implemented: */
+       //swab          swap every pair of input bytes: will abort on non-even reads
+               OP_iflag_skip_bytes,
 #endif
        };
-       int exitcode = EXIT_FAILURE;
-       size_t ibs = 512, obs = 512;
-       ssize_t n, w;
-       char *ibuf, *obuf;
-       /* And these are all zeroed at once! */
+       smallint exitcode = EXIT_FAILURE;
+       int i;
+       size_t ibs = 512;
+       char *ibuf;
+#if ENABLE_FEATURE_DD_IBS_OBS
+       size_t obs = 512;
+       char *obuf;
+#else
+# define obs  ibs
+# define obuf ibuf
+#endif
+       /* These are all zeroed at once! */
        struct {
-               int flags;
                size_t oc;
+               ssize_t prev_read_size; /* for detecting swab failure */
                off_t count;
                off_t seek, skip;
                const char *infile, *outfile;
        } Z;
-#define flags   (Z.flags  )
 #define oc      (Z.oc     )
+#define prev_read_size (Z.prev_read_size)
 #define count   (Z.count  )
 #define seek    (Z.seek   )
 #define skip    (Z.skip   )
@@ -191,10 +320,10 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
        INIT_G();
        //fflush_all(); - is this needed because of NOEXEC?
 
-       for (n = 1; argv[n]; n++) {
+       for (i = 1; argv[i]; i++) {
                int what;
                char *val;
-               char *arg = argv[n];
+               char *arg = argv[i];
 
 #if ENABLE_DESKTOP
                /* "dd --". NB: coreutils 6.9 will complain if they see
@@ -214,50 +343,39 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
 #if ENABLE_FEATURE_DD_IBS_OBS
                if (what == OP_ibs) {
                        /* Must fit into positive ssize_t */
-                       ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
+                       ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
                        /*continue;*/
                }
                if (what == OP_obs) {
-                       obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
+                       obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
                        /*continue;*/
                }
                if (what == OP_conv) {
-                       while (1) {
-                               /* find ',', replace them with NUL so we can use val for
-                                * index_in_strings() without copying.
-                                * We rely on val being non-null, else strchr would fault.
-                                */
-                               arg = strchr(val, ',');
-                               if (arg)
-                                       *arg = '\0';
-                               what = index_in_strings(conv_words, val);
-                               if (what < 0)
-                                       bb_error_msg_and_die(bb_msg_invalid_arg, val, "conv");
-                               flags |= (1 << what);
-                               if (!arg) /* no ',' left, so this was the last specifier */
-                                       break;
-                               /* *arg = ','; - to preserve ps listing? */
-                               val = arg + 1; /* skip this keyword and ',' */
-                       }
-                       continue; /* we trashed 'what', can't fall through */
+                       G.flags |= parse_comma_flags(val, conv_words, "conv");
+                       /*continue;*/
+               }
+               if (what == OP_iflag) {
+                       G.flags |= parse_comma_flags(val, iflag_words, "iflag") << FLAG_IFLAG_SHIFT;
+                       /*continue;*/
                }
 #endif
                if (what == OP_bs) {
-                       ibs = obs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, dd_suffixes);
+                       ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
+                       obs = ibs;
                        /*continue;*/
                }
                /* These can be large: */
                if (what == OP_count) {
-                       flags |= FLAG_COUNT;
-                       count = XATOU_SFX(val, dd_suffixes);
+                       G.flags |= FLAG_COUNT;
+                       count = XATOU_SFX(val, cwbkMG_suffixes);
                        /*continue;*/
                }
                if (what == OP_seek) {
-                       seek = XATOU_SFX(val, dd_suffixes);
+                       seek = XATOU_SFX(val, cwbkMG_suffixes);
                        /*continue;*/
                }
                if (what == OP_skip) {
-                       skip = XATOU_SFX(val, dd_suffixes);
+                       skip = XATOU_SFX(val, cwbkMG_suffixes);
                        /*continue;*/
                }
                if (what == OP_if) {
@@ -268,14 +386,27 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
                        outfile = val;
                        /*continue;*/
                }
-       } /* end of "for (argv[n])" */
+#if ENABLE_FEATURE_DD_STATUS
+               if (what == OP_status) {
+                       int n;
+                       n = index_in_strings(status_words, val);
+                       if (n < 0)
+                               bb_error_msg_and_die(bb_msg_invalid_arg_to, val, "status");
+                       G.flags |= FLAG_STATUS << n;
+                       /*continue;*/
+               }
+#endif
+       } /* end of "for (argv[i])" */
 
 //XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever
-       ibuf = obuf = xmalloc(ibs);
+       ibuf = xmalloc(ibs);
+       obuf = ibuf;
+#if ENABLE_FEATURE_DD_IBS_OBS
        if (ibs != obs) {
-               flags |= FLAG_TWOBUFS;
+               G.flags |= FLAG_TWOBUFS;
                obuf = xmalloc(obs);
        }
+#endif
 
 #if ENABLE_FEATURE_DD_SIGNAL_HANDLING
        signal_SA_RESTART_empty_mask(SIGUSR1, dd_output_status);
@@ -284,20 +415,20 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
        G.begin_time_us = monotonic_us();
 #endif
 
-       if (infile != NULL)
+       if (infile) {
                xmove_fd(xopen(infile, O_RDONLY), ifd);
-       else {
+       else {
                infile = bb_msg_standard_input;
        }
-       if (outfile != NULL) {
+       if (outfile) {
                int oflag = O_WRONLY | O_CREAT;
 
-               if (!seek && !(flags & FLAG_NOTRUNC))
+               if (!seek && !(G.flags & FLAG_NOTRUNC))
                        oflag |= O_TRUNC;
 
                xmove_fd(xopen(outfile, oflag), ofd);
 
-               if (seek && !(flags & FLAG_NOTRUNC)) {
+               if (seek && !(G.flags & FLAG_NOTRUNC)) {
                        if (ftruncate(ofd, seek * obs) < 0) {
                                struct stat st;
 
@@ -313,14 +444,15 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
                outfile = bb_msg_standard_output;
        }
        if (skip) {
-               if (lseek(ifd, skip * ibs, SEEK_CUR) < 0) {
-                       while (skip-- > 0) {
-                               n = safe_read(ifd, ibuf, ibs);
+               size_t blocksz = (G.flags & FLAG_SKIP_BYTES) ? 1 : ibs;
+               if (lseek(ifd, skip * blocksz, SEEK_CUR) < 0) {
+                       do {
+                               ssize_t n = safe_read(ifd, ibuf, blocksz);
                                if (n < 0)
                                        goto die_infile;
                                if (n == 0)
                                        break;
-                       }
+                       } while (--skip != 0);
                }
        }
        if (seek) {
@@ -328,13 +460,15 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
                        goto die_outfile;
        }
 
-       while (!(flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
+       while (!(G.flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) {
+               ssize_t n;
+
                n = safe_read(ifd, ibuf, ibs);
                if (n == 0)
                        break;
                if (n < 0) {
                        /* "Bad block" */
-                       if (!(flags & FLAG_NOERROR))
+                       if (!(G.flags & FLAG_NOERROR))
                                goto die_infile;
                        bb_simple_perror_msg(infile);
                        /* GNU dd with conv=noerror skips over bad blocks */
@@ -343,16 +477,37 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
                         * conv=noerror just ignores input bad blocks */
                        n = 0;
                }
+               if (G.flags & FLAG_SWAB) {
+                       uint16_t *p16;
+                       ssize_t n2;
+
+                       /* Our code allows only last read to be odd-sized */
+                       if (prev_read_size & 1)
+                               bb_error_msg_and_die("can't swab %lu byte buffer",
+                                               (unsigned long)prev_read_size);
+                       prev_read_size = n;
+
+                       /* If n is odd, last byte is not swapped:
+                        *  echo -n "qwe" | dd conv=swab
+                        * prints "wqe".
+                        */
+                       p16 = (void*) ibuf;
+                       n2 = (n >> 1);
+                       while (--n2 >= 0) {
+                               *p16 = bswap_16(*p16);
+                               p16++;
+                       }
+               }
                if ((size_t)n == ibs)
                        G.in_full++;
                else {
                        G.in_part++;
-                       if (flags & FLAG_SYNC) {
+                       if (G.flags & FLAG_SYNC) {
                                memset(ibuf + n, 0, ibs - n);
                                n = ibs;
                        }
                }
-               if (flags & FLAG_TWOBUFS) {
+               if (G.flags & FLAG_TWOBUFS) {
                        char *tmp = ibuf;
                        while (n) {
                                size_t d = obs - oc;
@@ -369,19 +524,20 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
                                        oc = 0;
                                }
                        }
-               } else if (write_and_stats(ibuf, n, obs, outfile))
-                       goto out_status;
+               } else {
+                       if (write_and_stats(ibuf, n, obs, outfile))
+                               goto out_status;
+               }
 
-               if (flags & FLAG_FSYNC) {
+               if (G.flags & FLAG_FSYNC) {
                        if (fsync(ofd) < 0)
                                goto die_outfile;
                }
        }
 
        if (ENABLE_FEATURE_DD_IBS_OBS && oc) {
-               w = full_write_or_warn(obuf, oc, outfile);
-               if (w < 0) goto out_status;
-               if (w > 0) G.out_part++;
+               if (write_and_stats(obuf, oc, obs, outfile))
+                       goto out_status;
        }
        if (close(ifd) < 0) {
  die_infile:
@@ -395,11 +551,12 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
 
        exitcode = EXIT_SUCCESS;
  out_status:
-       dd_output_status(0);
+       if (!ENABLE_FEATURE_DD_STATUS || !(G.flags & FLAG_STATUS_NONE))
+               dd_output_status(0);
 
        if (ENABLE_FEATURE_CLEAN_UP) {
                free(obuf);
-               if (flags & FLAG_TWOBUFS)
+               if (G.flags & FLAG_TWOBUFS)
                        free(ibuf);
        }