dd: add 'oflag=seek_bytes'

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                                             1632    1693     +61
packed_usage                                       33130   33150     +20
static.oflag_words                                     -      12     +12
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/0 up/down: 93/0)               Total: 93 bytes

Signed-off-by: Rostislav Skudnov <rostislav@tuxera.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Rostislav Skudnov 2018-10-15 10:26:15 +00:00 committed by Denys Vlasenko
parent f3e2838fc4
commit 3f6a978a0d
2 changed files with 25 additions and 9 deletions

View File

@ -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;
}

View File

@ -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