sg_opcodes.8

.TH SG_OPCODES "8" "April 2005" "sg3_utils-1.14" SG3_UTILS
.SH NAME
sg_opcodes \- reports information supported SCSI commands or
task management functions supported by the given device
.SH SYNOPSIS
.B sg_opcodes
[\fI-a\fR] [\fI-o=<opcode>\fR [\fI-s=<service_action>\fR ] ] [\fI-u\fR]
[\fI-u\fR] [\fI-v\fR] [\fI-V\fR] [\fI-?\fR] \fI<scsi_device>\fR
.SH DESCRIPTION
.\" Add any additional description here
.PP
This utility sends a REPORT SUPPORTED OPERATION CODES or a
REPORT SUPPORTED TASK MANAGEMENT FUNCTIONS SCSI command to the
given 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 "-o" option (perhaps with additional
information from the "-s" option).
.PP
The name of a SCSI command depends on its peripheral device type (e.g.
a disk) which is obtained from a standard SCSI INQUIRY command. Further
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.
.PP
A similar facility to query supported operation codes used to be 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 SCSI command in SPC-3 (revision 4) in February 2002.
.TP
-a
when all supported commands are being listed there is no requirement for
the device server (i.e. the target) 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 '-u' option are
both _not_ given then the list of supported commands is sorted
numerically (first by operation code and then by service action).
.TP
-o=<opcode>
the given device will be queried for the given operation code ("opcode")
which is the first byte of a SCSI command. Argument
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 target are listed.
.TP
-s=<service_action>
the given device will be queried for a command with the given service 
action ("service_action"). Used in conjunction with the '-o=<opcode>'
option. If '-s' is not given, '-o' is given and the command in question
does have a service action then a value of 0 will be assumed.
The "<service_action>" argument is hexadecimal and expected to be in the
range 0 to ffff inclusive.
.TP
-t
list supported task management functions. When this option is chosen
the '-a', '-o' and '-u' options are ignored.
.TP
-u
when all supported commands are being listed there is no requirement for
the device server (i.e. the target) to sort the list of commands. When
this option is given the list of supported commands is in the order
given by the target. When this option is not given the supported commands
are sorted numerically (first by operation code and then by service action). 
.TP
-v
verbose: print out cdb of issued commands prior to execution. '-vv'
and '-vvv' are also accepted yielding greater verbosity.
.TP
-V
print out version string
.TP
-?
output usage message. Ignore all other parameters.
.PP
In the 2.4 series of Linux kernels the given device must be
a SCSI generic (sg) device. In the 2.6 series block devices (e.g. disks
and SCSI DVDs) can also be specified. For example "sg_opcodes /dev/sda"
will work in the 2.6 series kernels.
.SH AUTHOR
Written by Doug Gilbert
.SH "REPORTING BUGS"
Report bugs to <dgilbert at interlog dot com>.
.SH COPYRIGHT
Copyright \(co 2004 Douglas Gilbert
.br
This software is distributed under the GPL version 2. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
.SH "SEE ALSO"
.B sg_inq(sg3_utils)