From 3f6a978a0dabe08e9df15b3f9ee2bd3cf8e3c441 Mon Sep 17 00:00:00 2001 From: Rostislav Skudnov Date: Mon, 15 Oct 2018 10:26:15 +0000 Subject: [PATCH] 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 Signed-off-by: Denys Vlasenko --- 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 0f130bcad..129637e24 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 cdf89b744..0e6f4a317 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 -- 2.25.1