qemu-img: add the 'dd' subcommand
This patch adds a basic dd subcommand analogous to dd(1) to qemu-img.
For the start, this implements the bs, if, of and count options and requires
both if and of to be specified (no stdin/stdout if not specified) and doesn't
support tty, pipes, etc.
The image format must be specified with -O for the output if the raw format
is not the intended one.
Two tests are added to test qemu-img dd.
Signed-off-by: Reda Sallahi <fullmanet@gmail.com>
Message-id: 20160810024312.14544-1-fullmanet@gmail.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[mreitz: Moved test 158 to 170]
Signed-off-by: Max Reitz <mreitz@redhat.com>
diff --git a/qemu-img.texi b/qemu-img.texi
index 449a19c..880293a 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -139,6 +139,20 @@
Skip the creation of the target volume
@end table
+Parameters to dd subcommand:
+
+@table @option
+
+@item bs=@var{block_size}
+defines the block size
+@item count=@var{blocks}
+sets the number of input blocks to copy
+@item if=@var{input}
+sets the input file
+@item of=@var{output}
+sets the output file
+@end table
+
Command description:
@table @option
@@ -310,6 +324,17 @@
volume has already been created with site specific options that cannot
be supplied through qemu-img.
+@item dd [-f @var{fmt}] [-O @var{output_fmt}] [bs=@var{block_size}] [count=@var{blocks}] if=@var{input} of=@var{output}
+
+Dd copies from @var{input} file to @var{output} file converting it from
+@var{fmt} format to @var{output_fmt} format.
+
+The data is by default read and written using blocks of 512 bytes but can be
+modified by specifying @var{block_size}. If count=@var{blocks} is specified
+dd will stop reading input after reading @var{blocks} input blocks.
+
+The size syntax is similar to dd(1)'s size syntax.
+
@item info [-f @var{fmt}] [--output=@var{ofmt}] [--backing-chain] @var{filename}
Give information about the disk image @var{filename}. Use it in
