Package: coreutils;
Reported by: Roman Rybalko <devel <at> romanr.info>
Date: Sat, 23 Jul 2011 22:42:04 UTC
Severity: normal
Tags: patch
Done: Pádraig Brady <P <at> draigBrady.com>
Bug is archived. No further changes may be made.
Message #8 received at 9157 <at> debbugs.gnu.org (full text, mbox):
From: Roman Rybalko <devel <at> romanr.info> To: undisclosed-recipients:; Subject: [PATCH] dd: sparse conv flag Date: Sat, 23 Jul 2011 20:08:01 +0400
---
doc/coreutils.texi | 4 +++
src/dd.c | 22 +++++++++++++++-
tests/Makefile.am | 1 +
tests/dd/sparse | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 96 insertions(+), 1 deletions(-)
create mode 100755 tests/dd/sparse
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 424446c..761c698 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -8127,6 +8127,10 @@ Pad every input block to size of @samp{ibs} with trailing zero bytes.
When used with @samp{block} or @samp{unblock}, pad with spaces instead of
zero bytes.
+@item sparse
+@opindex sparse
+Make sparse output file.
+
@end table
The following ``conversions'' are really file flags
diff --git a/src/dd.c b/src/dd.c
index 0824f6c..0393740 100644
--- a/src/dd.c
+++ b/src/dd.c
@@ -126,7 +126,8 @@ enum
C_NOCREAT = 010000,
C_EXCL = 020000,
C_FDATASYNC = 040000,
- C_FSYNC = 0100000
+ C_FSYNC = 0100000,
+ C_SPARSE = 0200000
};
/* Status bit masks. */
@@ -268,6 +269,7 @@ static struct symbol_value const conversions[] =
{"sync", C_SYNC}, /* Pad input records to ibs with NULs. */
{"fdatasync", C_FDATASYNC}, /* Synchronize output data before finishing. */
{"fsync", C_FSYNC}, /* Also synchronize output metadata. */
+ {"sparse", C_SPARSE}, /* Make sparse output file. */
{"", 0}
};
@@ -533,6 +535,9 @@ Each CONV symbol may be:\n\
fsync likewise, but also write metadata\n\
"), stdout);
fputs (_("\
+ sparse make sparse output file\n\
+"), stdout);
+ fputs (_("\
\n\
Each FLAG symbol may be:\n\
\n\
@@ -985,6 +990,21 @@ iwrite (int fd, char const *buf, size_t size)
{
ssize_t nwritten;
process_signals ();
+ if (conversions_mask & C_SPARSE)
+ {
+ off_t seek_size = 0;
+ while (total_written + seek_size < size && buf[total_written + seek_size] == 0)
+ ++seek_size;
+ if (seek_size)
+ {
+ off_t cur_off = 0;
+ cur_off = lseek(fd, seek_size, SEEK_CUR);
+ if (cur_off < 0)
+ break;
+ total_written += seek_size;
+ continue;
+ }
+ }
nwritten = write (fd, buf + total_written, size - total_written);
if (nwritten < 0)
{
diff --git a/tests/Makefile.am b/tests/Makefile.am
index ebd1b11..0f1376a 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -364,6 +364,7 @@ TESTS = \
dd/skip-seek \
dd/skip-seek2 \
dd/skip-seek-past-file \
+ dd/sparse \
dd/stderr \
dd/unblock \
dd/unblock-sync \
diff --git a/tests/dd/sparse b/tests/dd/sparse
new file mode 100755
index 0000000..f0e0806
--- /dev/null
+++ b/tests/dd/sparse
@@ -0,0 +1,70 @@
+#!/bin/sh
+# Ensure that dd conv=sparse works.
+
+# Copyright (C) 2003, 2005-2011 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+print_ver_ dd
+
+# sometimes we may read less than 1M
+dd if=/dev/zero of=sample0 count=1 bs=1M 2> /dev/null || fail=1
+[ "`stat -c %s sample0`" = "1048576" ] || fail=1
+dd if=/dev/urandom of=sample1 count=1 bs=1M 2> /dev/null || fail=1
+[ "`stat -c %s sample1`" = "1048576" ] || fail=1
+
+# test 1
+dd if=sample1 of=test1 seek=0 bs=1M 2> /dev/null || fail=1
+dd if=sample0 of=test1 seek=1 bs=1M 2> /dev/null || fail=1
+dd if=sample1 of=test1 seek=2 bs=1M 2> /dev/null || fail=1
+
+# test 1-1
+dd if=test1 of=out1-1 conv=sparse bs=1M 2> /dev/null || fail=1
+dd if=sample1 of=out1-1-check bs=1M 2> /dev/null || fail=1
+dd if=sample1 of=out1-1-check seek=2 bs=1M 2> /dev/null || fail=1
+[ "`stat -c '%s %b %B' out1-1`" = "`stat -c '%s %b %B' out1-1-check`" ] || fail=1
+
+# test 1-2
+dd if=test1 of=out1-2 seek=1 conv=sparse bs=1M 2> /dev/null || fail=1
+dd if=sample1 of=out1-2-check seek=1 bs=1M 2> /dev/null || fail=1
+dd if=sample1 of=out1-2-check seek=3 bs=1M 2> /dev/null || fail=1
+[ "`stat -c '%s %b %B' out1-2`" = "`stat -c '%s %b %B' out1-2-check`" ] || fail=1
+
+# test 1-3
+dd if=test1 of=out1-3 seek=1 skip=1 conv=sparse bs=1M 2> /dev/null || fail=1
+dd if=sample1 of=out1-3-check seek=2 bs=1M 2> /dev/null || fail=1
+[ "`stat -c '%s %b %B' out1-3`" = "`stat -c '%s %b %B' out1-3-check`" ] || fail=1
+
+# test 2
+dd if=sample0 of=test2 seek=0 bs=1M 2> /dev/null || fail=1
+dd if=sample1 of=test2 seek=1 bs=1M 2> /dev/null || fail=1
+dd if=sample0 of=test2 seek=2 bs=1M 2> /dev/null || fail=1
+
+# test 2-1
+dd if=test2 of=out2-1 conv=sparse bs=1M 2> /dev/null || fail=1
+dd if=sample1 of=out2-1-check seek=1 bs=1M 2> /dev/null || fail=1
+[ "`stat -c '%s %b %B' out2-1`" = "`stat -c '%s %b %B' out2-1-check`" ] || fail=1
+
+# test 2-2
+dd if=test2 of=out2-2 seek=1 conv=sparse bs=1M 2> /dev/null || fail=1
+dd if=sample1 of=out2-2-check seek=2 bs=1M 2> /dev/null || fail=1
+[ "`stat -c '%s %b %B' out2-2`" = "`stat -c '%s %b %B' out2-2-check`" ] || fail=1
+
+# test 2-3
+dd if=test2 of=out2-3 seek=1 skip=1 conv=sparse bs=1M 2> /dev/null || fail=1
+dd if=sample1 of=out2-3-check seek=1 bs=1M 2> /dev/null || fail=1
+[ "`stat -c '%s %b %B' out2-3`" = "`stat -c '%s %b %B' out2-3-check`" ] || fail=1
+
+Exit $fail
--
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