sg_get_config - send SCSI GET CONFIGURATION command (MMC-4 +)
] [ --inner-hex
] [ --rt=RT
] [ --version
Sends a SCSI GET CONFIGURATION command to DEVICE
and decodes the
response. The response includes the features and profiles of the device.
Typically these devices are CD, DVD, HD-DVD and BD players that may (but not
necessarily) have media in them. These devices may well be connected via
ATAPI, USB or IEEE 1394 transports. In such cases they are "SCSI"
devices only in the sense that they use the "Multi-Media command"
set (MMC). MMC is a specialized SCSI command set whose definition can be found
at http://www.t10.org .
This utility is based on the MMC-4 and later draft standards. See section 5 on
"Features and Profile for Multi_Media devices" for more information
on specific feature parameters and profiles. The manufacturer's product manual
may also be useful.
Since modern DVD and BD writers support many features and profiles, the decoded
output from this utility can be large. There are various ways to cut down the
output. If the --brief
option is used only the feature names are shown
and the feature parameters are not decoded. Alternatively if only one feature
is of interest then this combination of options is appropriate: "--rt=2
". Another possibility is to show only the features
that are relevant to the media in the drive (i.e. "current") with
the "--rt=1" option.
Arguments to long options are mandatory for short options as well.
- -b, --brief
- show the feature names but don't decode the parameters of
those features. When used with --list outputs known feature names
but not known profile names.
- -c, --current
- output features marked as current. This option is
equivalent to '--rt=1'.
- -h, --help
- output the usage message then exit.
- -H, --hex
- output the response in hex (don't decode response).
- -i, --inner-hex
- decode to the feature name level then output each feature's
data in hex.
- -l, --list
- list all known feature and profile names. Ignore the device
name (if given). Simply lists the feature names and profiles (followed by
their hex values) that this utility knows about. If --brief is also
given then only feature names are listed.
- -q, --readonly
- opens the DEVICE read-only rather than read-write which is
the default. The Linux sg driver needs read-write access for the SCSI GET
CONFIGURATION command but other access methods may require read-only
- -r, --rt=RT
- where RT is the field of that name in the GET
CONFIGURATION cdb. Allowable values are 0, 1, 2, or 3 . The command's
action also depends on the value given to the --starting=FC option.
The default value is 0. When RT is 0 then all features, regardless
of currency, are returned (whose feature code is greater than or equal to
FC given to --starting=). When RT is 1 then all
current features are returned (whose feature code is greater than or equal
to FC). When RT is 2 then the feature whose feature code is
equal to FC, if any, is returned. When RT is 3 the response
is reserved (probably yields an "illegal field in cdb" error).
To simplify the meanings of the RT values are:
0 : all features, current on not
1 : only current features
2 : only feature whose code is FC
3 : reserved
- -R, --raw
- output response in binary (to stdout). Note that the short
form is -R unlike most other utilities in this package that use
-r for this action.
- -s, --starting=FC
- where FC is the feature code value. This option
works closely with the --rt=RT option. The FC value is in
the range 0 to 65535 (0xffff) inclusive. Its default value is 0. A value
prefixed with "0x" (or a trailing 'h') is interpreted as
- -v, --verbose
- increase the level of verbosity, (i.e. debug output).
- -V, --version
- print the version string and then exit.
There are multiple versions of the MMC (draft) standards: MMC , MMC-2
, MMC-3 , MMC-4 and MMC-5. The first three are now ANSI INCITS
standards with the year they became standards shown in brackets. The draft
immediately prior to standardization can be found at http://www.t10.org . In
the initial MMC standard there was no GET CONFIGURATION command and the
relevant information was obtained from the "CD capabilities and
mechanical status mode page" (mode page 0x2a). It was later renamed the
"MM capabilities and mechanical status mode page" and has been made
obsolete in MMC-4 and MMC-5. The GET CONFIGURATION command was introduced in
MMC-2 and has become a replacement for that mode page. New features such as
support for "BD" (blue ray) media type can only be found by using
the GET CONFIGURATION command. Hence older CD players may not support the GET
CONFIGURATION command in which case the "MM capabilities ..." mode
page can be checked with sdparm(8), sginfo(8) or sg_modes(8).
In the 2.4 series of Linux kernels the DEVICE
must be a SCSI generic (sg)
device. In the 2.6 series block devices can also be specified. For example
"sg_get_config /dev/hdc" will work in the 2.6 series kernels as long
as /dev/hdc is an ATAPI device. In the 2.6 series external DVD writers
attached via USB could be queried with "sg_get_config /dev/scd1" for
The exit status of sg_get_config is 0 when it is successful. Otherwise see the
sg3_utils(8) man page.
Written by Douglas Gilbert.
Report bugs to <dgilbert at interlog dot com>.
Copyright © 2004-2012 Douglas Gilbert
This software is distributed under a FreeBSD license. There is NO warranty; not
even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
sginfo(8), sg_modes(8), sg_inq(8), sg_prevent(8), sg_start(8) [all in