bionic (8) sg_read_buffer.8.gz
NAME
sg_read_buffer - send SCSI READ BUFFER command
SYNOPSIS
sg_read_buffer [--help] [--hex] [--id=ID] [--length=LEN] [--mode=MO] [--offset=OFF] [--raw] [--readonly]
[--verbose] [--version] DEVICE
DESCRIPTION
Sends a SCSI READ BUFFER command to the DEVICE, and if there is a response either decodes it, prints it
in hexadecimal or sends it in binary to stdout. If a response is received for a "descriptor" mode then,
in the absence of --hex and --raw, it is decoded. Response for non-descriptor modes are output in
hexadecimal unless the --raw option is given.
OPTIONS
Arguments to long options are mandatory for short options as well.
-h, --help
output the usage message then exit. If used multiple times also prints the mode names and their
acronyms.
-H, --hex
output the response in hexadecimal. When given twice the response is output in hex with the
corresponding representation in ASCII to the right of each line.
-i, --id=ID
this option sets the buffer id field in the cdb. ID is a value between 0 (default) and 255
inclusive.
-l, --length=LEN
where LEN is the length, in bytes, that is placed in the "allocation length" field in the cdb. The
default value is 4 (bytes). The device may respond with less bytes.
-m, --mode=MO
this option sets the mode field in the cdb. MO is a value between 0 (default) and 31 inclusive.
Alternatively an abbreviation can be given. See the MODES section below. To list the available
mode abbreviations use an invalid one (e.g. '--mode=xxx'). As an example, to fetch the read buffer
descriptor give '--mode=desc' .
-o, --offset=OFF
this option sets the buffer offset field in the cdb. OFF is a value between 0 (default) and
2**24-1 . It is a byte offset.
-r, --raw
if a response is received then it is sent in binary to stdout.
-R, --readonly
open the DEVICE read-only (e.g. in Unix with the O_RDONLY flag). The default is to open it
read-write.
-v, --verbose
increase the level of verbosity, (i.e. debug output).
-V, --version
print the version string and then exit.
MODES
Following is a list of READ BUFFER command settings for the MODE field. First is an acronym accepted by
the MO argument of this utility. Following the acronym in square brackets are the corresponding decimal
and hex values that may also be given for MO. The following are listed in numerical order.
hd [0, 0x0]
Combined header and data (obsolete in SPC-4).
vendor [1, 0x1]
Vendor specific.
data [2, 0x2]
Data.
desc [3, 0x3]
Descriptor: yields 4 bytes that contain an offset boundary field (1 byte) and buffer capacity (3
bytes).
echo [10, 0xa]
Read data from echo buffer (was called "Echo buffer" in SPC-3).
echo_desc [11, 0xb]
Echo buffer descriptor: yields 4 bytes of which the last (lowest) 13 bits represent the echo
buffer capacity. The maximum echo buffer size is 4096 bytes.
en_ex [26, 0x1a]
Enable expander communications protocol and Echo buffer. Made obsolete in SPC-4.
err_hist [28, 0x1c]
Error history. Introduced in SPC-4.
NOTES
All numbers given with options are assumed to be decimal. Alternatively numerical values can be given in
hexadecimal preceded by either "0x" or "0X" (or has a trailing "h" or "H").
EXIT STATUS
The exit status of sg_read_buffer is 0 when it is successful. Otherwise see the sg3_utils(8) man page.
AUTHORS
Written by Luben Tuikov and Douglas Gilbert.
REPORTING BUGS
Report bugs to <dgilbert at interlog dot com>.
COPYRIGHT
Copyright © 2006-2014 Luben Tuikov and Douglas Gilbert
This software is distributed under a FreeBSD license. There is NO warranty; not even for MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.
SEE ALSO
sg_write_buffer(sg3_utils)