From 4eb46e1be6d88eaf077252ce93127ebf00aa8ef2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= Date: Wed, 24 Mar 2021 16:01:42 +0100 Subject: [PATCH] dd: support iflag=count_bytes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It allows passing amount of bytes in the count= function old new delta packed_usage 33599 33617 +18 static.iflag_words 29 41 +12 dd_main 1601 1607 +6 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 3/0 up/down: 36/0) Total: 36 bytes Signed-off-by: Rafał Miłecki Signed-off-by: Denys Vlasenko --- coreutils/dd.c | 50 ++++++++++++++++++++++++------------- testsuite/dd/dd-count-bytes | 1 + 2 files changed, 33 insertions(+), 18 deletions(-) create mode 100644 testsuite/dd/dd-count-bytes diff --git a/coreutils/dd.c b/coreutils/dd.c index 24d7f0b84..a243f718b 100644 --- a/coreutils/dd.c +++ b/coreutils/dd.c @@ -59,7 +59,7 @@ //usage: "[if=FILE] [of=FILE] [" IF_FEATURE_DD_IBS_OBS("ibs=N obs=N/") "bs=N] [count=N] [skip=N] [seek=N]\n" //usage: IF_FEATURE_DD_IBS_OBS( //usage: " [conv=notrunc|noerror|sync|fsync]\n" -//usage: " [iflag=skip_bytes|fullblock|direct] [oflag=seek_bytes|append|direct]" +//usage: " [iflag=skip_bytes|count_bytes|fullblock|direct] [oflag=seek_bytes|append|direct]" //usage: ) //usage:#define dd_full_usage "\n\n" //usage: "Copy a file with converting and formatting\n" @@ -82,6 +82,7 @@ //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: "\n iflag=count_bytes count=N is in bytes" //usage: "\n oflag=seek_bytes seek=N is in bytes" //usage: "\n iflag=direct O_DIRECT input" //usage: "\n oflag=direct O_DIRECT output" @@ -136,21 +137,22 @@ enum { 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, - FLAG_FULLBLOCK = (1 << 6) * ENABLE_FEATURE_DD_IBS_OBS, - FLAG_IDIRECT = (1 << 7) * ENABLE_FEATURE_DD_IBS_OBS, + FLAG_IFLAG_SHIFT = 5, + FLAG_SKIP_BYTES = (1 << 5) * ENABLE_FEATURE_DD_IBS_OBS, + FLAG_COUNT_BYTES = (1 << 6) * ENABLE_FEATURE_DD_IBS_OBS, + FLAG_FULLBLOCK = (1 << 7) * ENABLE_FEATURE_DD_IBS_OBS, + FLAG_IDIRECT = (1 << 8) * ENABLE_FEATURE_DD_IBS_OBS, /* end of input flags */ /* start of output flags */ - FLAG_OFLAG_SHIFT = 8, - FLAG_SEEK_BYTES = (1 << 8) * ENABLE_FEATURE_DD_IBS_OBS, - FLAG_APPEND = (1 << 9) * ENABLE_FEATURE_DD_IBS_OBS, - FLAG_ODIRECT = (1 << 10) * ENABLE_FEATURE_DD_IBS_OBS, + FLAG_OFLAG_SHIFT = 9, + FLAG_SEEK_BYTES = (1 << 9) * ENABLE_FEATURE_DD_IBS_OBS, + FLAG_APPEND = (1 << 10) * ENABLE_FEATURE_DD_IBS_OBS, + FLAG_ODIRECT = (1 << 11) * ENABLE_FEATURE_DD_IBS_OBS, /* end of output flags */ - FLAG_TWOBUFS = (1 << 11) * ENABLE_FEATURE_DD_IBS_OBS, - FLAG_COUNT = 1 << 12, - FLAG_STATUS_NONE = 1 << 13, - FLAG_STATUS_NOXFER = 1 << 14, + FLAG_TWOBUFS = (1 << 12) * ENABLE_FEATURE_DD_IBS_OBS, + FLAG_COUNT = 1 << 13, + FLAG_STATUS_NONE = 1 << 14, + FLAG_STATUS_NOXFER = 1 << 15, }; static void dd_output_status(int UNUSED_PARAM cur_signal) @@ -175,8 +177,9 @@ static void dd_output_status(int UNUSED_PARAM cur_signal) //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, + fprintf(stderr, /*G.total_bytes < 1024 + ? "%llu bytes copied, " : */ "%llu bytes (%sB) copied, " + , G.total_bytes, /* show fractional digit, use suffixes */ make_human_readable_str(G.total_bytes, 1, 0) ); @@ -317,7 +320,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv) static const char conv_words[] ALIGN1 = "notrunc\0""sync\0""noerror\0""fsync\0""swab\0"; static const char iflag_words[] ALIGN1 = - "skip_bytes\0""fullblock\0""direct\0"; + "skip_bytes\0""count_bytes\0""fullblock\0""direct\0"; static const char oflag_words[] ALIGN1 = "seek_bytes\0append\0""direct\0"; #endif @@ -359,6 +362,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv) /* Partially implemented: */ //swab swap every pair of input bytes: will abort on non-even reads OP_iflag_skip_bytes, + OP_iflag_count_bytes, OP_iflag_fullblock, OP_iflag_direct, OP_oflag_seek_bytes, @@ -551,8 +555,17 @@ int dd_main(int argc UNUSED_PARAM, char **argv) goto die_outfile; } - while (!(G.flags & FLAG_COUNT) || (G.in_full + G.in_part != count)) { - ssize_t n = dd_read(ibuf, ibs); + while (1) { + ssize_t n = ibs; + + if (G.flags & FLAG_COUNT) { + if (count == 0) + break; + if ((G.flags & FLAG_COUNT_BYTES) && count < ibs) + n = count; + } + + n = dd_read(ibuf, n); if (n == 0) break; if (n < 0) { @@ -587,6 +600,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv) p16++; } } + count -= (G.flags & FLAG_COUNT_BYTES) ? n : 1; if ((size_t)n == ibs) G.in_full++; else { diff --git a/testsuite/dd/dd-count-bytes b/testsuite/dd/dd-count-bytes new file mode 100644 index 000000000..0730cba5e --- /dev/null +++ b/testsuite/dd/dd-count-bytes @@ -0,0 +1 @@ +test "$(echo I WANT | busybox dd count=3 iflag=count_bytes 2>/dev/null)" = "I W"