[PATCH] dd: add 'oflag=seek_bytes'
Denys Vlasenko
vda.linux at googlemail.com
Tue Oct 30 16:06:05 UTC 2018
Applied, thanks!
On Mon, Oct 15, 2018 at 12:35 PM Rostislav Skudnov <rostislav at tuxera.com> wrote:
>
> Allow specifying position in the output file in bytes instead of
> obs-sized blocks, improve compatibility with GNU dd.
>
> function old new delta
> dd_main 1448 1518 +70
> .rodata 26143 26167 +24
> static.oflag_words - 12 +12
> ------------------------------------------------------------------------------
> (add/remove: 1/0 grow/shrink: 2/0 up/down: 106/0) Total: 106 bytes
>
> Signed-off-by: Rostislav Skudnov <rostislav at tuxera.com>
> ---
> coreutils/dd.c | 33 ++++++++++++++++++++++++---------
> docs/posix_conformance.txt | 1 +
> 2 files changed, 25 insertions(+), 9 deletions(-)
>
> diff --git a/coreutils/dd.c b/coreutils/dd.c
> index 0f130bc..129637e 100644
> --- a/coreutils/dd.c
> +++ b/coreutils/dd.c
> @@ -37,7 +37,7 @@
> //config: elapsed time and speed.
> //config:
> //config:config FEATURE_DD_IBS_OBS
> -//config: bool "Enable ibs, obs, iflag and conv options"
> +//config: bool "Enable ibs, obs, iflag, oflag and conv options"
> //config: default y
> //config: depends on DD
> //config: help
> @@ -57,7 +57,7 @@
>
> //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|fullblock]")
> +//usage: " [seek=N]" IF_FEATURE_DD_IBS_OBS(" [conv=notrunc|noerror|sync|fsync] [iflag=skip_bytes|fullblock] [oflag=seek_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"
> @@ -80,6 +80,7 @@
> //usage: "\n conv=swab Swap every pair of bytes"
> //usage: "\n iflag=skip_bytes skip=N is in bytes"
> //usage: "\n iflag=fullblock Read full blocks"
> +//usage: "\n oflag=seek_bytes seek=N is in bytes"
> //usage: )
> //usage: IF_FEATURE_DD_STATUS(
> //usage: "\n status=noxfer Suppress rate output"
> @@ -133,10 +134,14 @@ enum {
> FLAG_SKIP_BYTES = (1 << 5) * ENABLE_FEATURE_DD_IBS_OBS,
> FLAG_FULLBLOCK = (1 << 6) * ENABLE_FEATURE_DD_IBS_OBS,
> /* end of input flags */
> - FLAG_TWOBUFS = (1 << 7) * ENABLE_FEATURE_DD_IBS_OBS,
> - FLAG_COUNT = 1 << 8,
> - FLAG_STATUS_NONE = 1 << 9,
> - FLAG_STATUS_NOXFER = 1 << 10,
> + /* start of output flags */
> + FLAG_OFLAG_SHIFT = 7,
> + FLAG_SEEK_BYTES = (1 << 7) * ENABLE_FEATURE_DD_IBS_OBS,
> + /* end of output flags */
> + FLAG_TWOBUFS = (1 << 8) * ENABLE_FEATURE_DD_IBS_OBS,
> + FLAG_COUNT = 1 << 9,
> + FLAG_STATUS_NONE = 1 << 10,
> + FLAG_STATUS_NOXFER = 1 << 11,
> };
>
> static void dd_output_status(int UNUSED_PARAM cur_signal)
> @@ -250,7 +255,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
> static const char keywords[] ALIGN1 =
> "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""iflag\0"
> + "ibs\0""obs\0""conv\0""iflag\0""oflag\0"
> #endif
> ;
> #if ENABLE_FEATURE_DD_IBS_OBS
> @@ -258,6 +263,8 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
> "notrunc\0""sync\0""noerror\0""fsync\0""swab\0";
> static const char iflag_words[] ALIGN1 =
> "skip_bytes\0""fullblock\0";
> + static const char oflag_words[] ALIGN1 =
> + "seek_bytes\0";
> #endif
> #if ENABLE_FEATURE_DD_STATUS
> static const char status_words[] ALIGN1 =
> @@ -276,6 +283,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
> OP_obs,
> OP_conv,
> OP_iflag,
> + OP_oflag,
> /* Must be in the same order as FLAG_XXX! */
> OP_conv_notrunc = 0,
> OP_conv_sync,
> @@ -297,6 +305,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
> //swab swap every pair of input bytes: will abort on non-even reads
> OP_iflag_skip_bytes,
> OP_iflag_fullblock,
> + OP_oflag_seek_bytes,
> #endif
> };
> smallint exitcode = EXIT_FAILURE;
> @@ -368,6 +377,10 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
> G.flags |= parse_comma_flags(val, iflag_words, "iflag") << FLAG_IFLAG_SHIFT;
> /*continue;*/
> }
> + if (what == OP_oflag) {
> + G.flags |= parse_comma_flags(val, oflag_words, "oflag") << FLAG_OFLAG_SHIFT;
> + /*continue;*/
> + }
> #endif
> if (what == OP_bs) {
> ibs = xatoul_range_sfx(val, 1, ((size_t)-1L)/2, cwbkMG_suffixes);
> @@ -439,7 +452,8 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
> xmove_fd(xopen(outfile, oflag), ofd);
>
> if (seek && !(G.flags & FLAG_NOTRUNC)) {
> - if (ftruncate(ofd, seek * obs) < 0) {
> + size_t blocksz = (G.flags & FLAG_SEEK_BYTES) ? 1 : obs;
> + if (ftruncate(ofd, seek * blocksz) < 0) {
> struct stat st;
>
> if (fstat(ofd, &st) < 0
> @@ -472,7 +486,8 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
> }
> }
> if (seek) {
> - if (lseek(ofd, seek * obs, SEEK_CUR) < 0)
> + size_t blocksz = (G.flags & FLAG_SEEK_BYTES) ? 1 : obs;
> + if (lseek(ofd, seek * blocksz, SEEK_CUR) < 0)
> goto die_outfile;
> }
>
> diff --git a/docs/posix_conformance.txt b/docs/posix_conformance.txt
> index cdf89b7..0e6f4a3 100644
> --- a/docs/posix_conformance.txt
> +++ b/docs/posix_conformance.txt
> @@ -182,6 +182,7 @@ dd compatibility options:
> conv=fsync | yes | |
> iflag=skip_bytes| yes | |
> iflag=fullblock | yes | |
> + oflag=seek_bytes| yes | |
>
> df POSIX options
> option | exists | compliant | remarks
> --
> 2.1.4
>
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