Provided by: sg3-utils_1.46-3ubuntu4_amd64 
NAME
sg_opcodes - report supported SCSI commands or task management functions
SYNOPSIS
sg_opcodes [--alpha] [--compact] [--enumerate] [--help] [--hex] [--mask] [--mlu] [--no-inquiry]
[--opcode=OP[,SA]] [--pdt=DT] [--raw] [--rctd] [--repd] [--sa=SA] [--tmf] [--unsorted] [--verbose]
[--version] DEVICE
sg_opcodes [-a] [-c] [-e] [-H] [-m] [-M] [-n] [-o=OP] [-p=DT] [-q] [-R] [-s=SA] [-t] [-u] [-v] [-V] [-?]
DEVICE
DESCRIPTION
This utility sends a SCSI REPORT SUPPORTED OPERATION CODES or a REPORT SUPPORTED TASK MANAGEMENT
FUNCTIONS command to the DEVICE and then outputs the response. The default action is to report supported
operation codes. In this mode it will either list all supported commands or give detailed information on
a specific command identified by the --opcode=OP option (perhaps with additional information from the
--sa=SA option).
The name of a SCSI command depends on its peripheral device type (e.g. a disk). The REPORT SUPPORTED
OPERATION CODES and REPORT SUPPORTED TASK MANAGEMENT FUNCTIONS commands are not supported in the MMC
command set for CD and DVD devices. This utility does an INQUIRY to obtain the peripheral device type and
prints out the vendor, product and revision strings.
A similar facility to query supported operation codes previously was available via the CmdDt bit in the
SCSI INQUIRY command (see sg_inq(8)). However that facility was made obsolete and replaced by the REPORT
SUPPORTED OPERATION CODES command in SPC-3 (revision 4) during February 2002.
This utility supports two command line syntaxes, the preferred one is shown first in the synopsis and
explained in this section. A later section on the old command line syntax outlines the second group of
options.
OPTIONS
Arguments to long options are mandatory for short options as well.
-a, --alpha
when all supported commands are being listed there is no requirement for the device server (i.e.
the DEVICE) to sort the list of commands. When this option is given the list of supported commands
is sorted by name (alphabetically). When this option and the --unsorted option are both _not_
given then the list of supported commands is sorted numerically (first by operation code and then
by service action).
-c, --compact
some command names, especially those associated with some service actions, are getting longer.
This may cause line wrap in the one line per command mode on some terminals. When this option is
given the opcode and service action fields are combined into a single field with the service
action, prefixed by a comma shown directly after the opcode. If there is no service action
associated with the command, then the comma and the service action are not shown after the opcode.
The CDB size field is not shown when this option is given.
-e, --enumerate
this option prints the name of the SCSI command based on the given opcode, peripheral device type
and optionally the service action. If given, DEVICE is ignored. The opcode, peripheral device type
and service action default to zero if not given. Thus if this option is the only option given then
"Test Unit ready" is output since its opcode is 0, it has no service action and it is common to
all peripheral device types since it is defined in the SCSI Primary Commands (SPC) standard(s).
-h, --help
outputs the usage message summarizing command line options then exits. Ignores DEVICE if given.
-H, --hex
outputs the response in ASCII hexadecimal to stdout.
-m, --mask
additionally prints out the cdb mask in hex. So a 12 byte cdb will have a 12 byte hexadecimal
mask. If the hexadecimal is expanded (mentally) to binary then a "1" means the corresponding
position in the cdb may be set. And "0" means the corresponding position in the cdb must not be
set. For "0" mask positions that a user tries to set in a cdb, the device may either ignore it or
report an error, typically with a sense key of "illegal request".
-M, --mlu
additionally prints out an indication (0 or 1) whether the command effects all logical units in
the containing target. MLU (Multiple Logical Units) is a bit in the REPORT SUPPORTED OPERATION
CODES response introduced by proposal 18-045r1 (and possibly in spc5r20). Without the option, the
default output format which lists all opcodes, does not include a MLU indication.
-n, --no-inquiry
Prior to calling a SCSI REPORT SUPPORTED OPERATION CODES or a REPORT SUPPORTED TASK MANAGEMENT
FUNCTIONS command, a SCSI INQUIRY command is performed. The reason is to determine the peripheral
device type (pdt) of the DEVICE as this is helpful in translating operation codes to the command
names. By default this utility prints a summary of INQUIRY command response on stdout. If this
option (or the --raw option) is given then that summary is not printed on stdout.
-O, --old
Switch to older style options. Please use as first option.
-o, --opcode=OP[,SA]
the DEVICE will be queried for the given operation code (i.e. the OP value) which is the first
byte of a SCSI command. Optionally, if a SA value is given, it will be used as that SCSI command's
service action. Note that OP and OP,0 are not the same thing, as SCSI does allow the service
action to be 0 (but it is not comman). OP and SA are decimal unless prefixed by "0x" or they have
a trailing "h". OP should be in the range 0 to 255 (0xff) inclusive. SA should be in the range 0
to 65535 (0xffff) inclusive. When this option is not given then all available SCSI commands
supported by the DEVICE are listed.
-p, --pdt=DT
where DT is the peripheral device type. This is used together with the --enumerate to
differentiate when a command opcode (and perhaps service action) is shared by multiple device
types.
This option may also be used with the --no-inquiry option to suppress this utility doing an
INQUIRY command since the main reason for doing that is to find the peripheral device type of the
DEVICE.
-r, --raw
output the response in binary to stdout. Error messages and warnings, if any, are sent to stderr.
-R, --rctd
set report command timeout descriptor (RCTD) bit in the cdb. The response may or may not contain
command timeout descriptors. If available they are output. If supported there are two values: a
nominal command timeout and a recommended command timeout. Both have units of seconds. A value of
zero means that no timeout is indicated and this is shown in the corresponding decoded output as
"-".
-q, --repd
set read extended parameter data (REPD) bit in the report task management functions cdb. 16 bytes
rather than the default 4 bytes expected in the response. This was added in SPC-4 (revision 26).
-s, --sa=SA
the DEVICE will be queried for a command with the given service action (i.e. the SA value). Used
in conjunction with the --opcode=OP option. If this option is not given, --opcode=OP is given and
the command in question does have a service action then a value of 0 will be assumed. SA is
decimal and expected to be in the range 0 to 65535 (0xffff) inclusive.
-t, --tmf
list supported task management functions. This is done with the SCSI REPORT SUPPORTED TASK
MANAGEMENT FUNCTIONS command. When this option is chosen the --alpha, --opcode=OP, --rctd,
--sa=SA and --unsorted options are ignored.
-u, --unsorted
when all supported commands are being listed there is no requirement for the device server (i.e.
the DEVICE) to sort the list of commands. When this option is given the list of supported commands
is in the order given by the DEVICE. When this option is not given the supported commands are
sorted numerically (first by operation code and then by service action).
-v, --verbose
increase level of verbosity. Can be used multiple times.
-V, --version
print out version string then exit.
NOTES
As of SPC-5 revision 8 the recognized task management functions are: abort set, abort task set, clear
ACA, clear task set, logical unit reset, query task, query asynchronous event, query task set, and I_T
nexus reset. In SPC-4 revision 26 target reset and wakeup task management functions were made obsolete.
In the 2.4 series of Linux kernels the DEVICE must be a SCSI generic (sg) device. In the 2.6 series block
devices (e.g. SCSI disks and DVD drives) can also be specified. For example "sg_opcodes /dev/sda" will
work in the 2.6 series kernels.
EXIT STATUS
The exit status of sg_opcodes is 0 when it is successful. Otherwise see the sg3_utils(8) man page.
OLDER COMMAND LINE OPTIONS
The options in this section were the only ones available prior to sg3_utils version 1.23 . Since then
this utility defaults to the newer command line options which can be overridden by using --old (or -O) as
the first option. See the ENVIRONMENT VARIABLES section for another way to force the use of these older
command line options.
-a sort command alphabetically. Equivalent to --alpha in main description.
-c see the --compact option above.
-e see the --enumerate option above.
-H see the --hex option above.
-m see the --mask option above.
-n don't print a summary of the SCSI INQUIRY response on stdout.
-N, --new
Switch to the newer style options.
-o=OP the DEVICE will be queried for the given operation code (i.e. OP) which is the first byte of a
SCSI command. OP is hexadecimal and expected to be in the range 0 to ff inclusive. When this
option is not given then all available SCSI commands supported by the DEVICE are listed.
-p=DT see the --pdt=DT option above.
-q set the read extended parameter data (REPD) bit in report TMF cdb. Equivalent to --repd in main
description.
-R set the report command timeout descriptor (RCTD) bit in cdb. Equivalent to --rctd in main
description.
-s=SA the DEVICE will be queried for a command with the given service action (i.e. SA). Used in
conjunction with the -o=OP option. If this option is not given, -o=OP is given and the command in
question does have a service action then a value of 0 will be assumed. SA is hexadecimal and
expected to be in the range 0 to ffff inclusive.
-t list supported task management functions. Equivalent to --tmf in the main description.
-u output all supported commands in the order given by DEVICE. Equivalent to --unsorted in main
description.
-v increase level of verbosity. Can be used multiple times.
-V print out version string then exit.
-? output usage message. Ignore all other parameters.
EXAMPLES
The examples in this page use Linux device names. For suitable device names in other supported Operating
Systems see the sg3_utils(8) man page.
To see the information about a specific command give its operation code to the '--op=' option. A command
line invocation is shown first followed by a typical response:
# sg_opcodes --op=93h /dev/sdb
Opcode=0x93
Command_name: Write same(16)
Command supported [conforming to SCSI standard]
Usage data: 93 e2 00 00 00 00 ff ff ff ff 00 00 ff ff 00 00
The next example shows the supported task management functions:
# sg_opcodes --tmf -n /dev/sdb
Task Management Functions supported by device:
Abort task
Abort task set
Clear ACA
Clear task set
Logical unit reset
Query task
Enumerate can be used to look up a SCSI command name in the absence of a device that supports that
command. The opcode and service action (if required) should be supplied:
# sg_opcodes --enumerate --op=0x9b,0xa
SCSI command:
Read buffer(16), read data from echo buffer
ENVIRONMENT VARIABLES
Since sg3_utils version 1.23 the environment variable SG3_UTILS_OLD_OPTS can be given. When it is present
this utility will expect the older command line options. So the presence of this environment variable is
equivalent to using --old (or -O) as the first command line option.
AUTHOR
Written by Douglas Gilbert
REPORTING BUGS
Report bugs to <dgilbert at interlog dot com>.
COPYRIGHT
Copyright © 2004-2021 Douglas Gilbert
This software is distributed under the GPL version 2. There is NO warranty; not even for MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.
SEE ALSO
sg_inq(sg3_utils)
sg3_utils-1.46 March 2020 SG_OPCODES(8)