1SG_READ_BUFFER(8) SG3_UTILS SG_READ_BUFFER(8)
2
6 sg_read_buffer - send SCSI READ BUFFER command
7
9 sg_read_buffer [--help] [--hex] [--id=ID] [--inhex=FN] [--length=LEN]
10 [--mode=MO] [--offset=OFF] [--raw] [--readonly] [--specific=MS] [--ver‐
11 bose] [--version] DEVICE
12
14 Sends a SCSI READ BUFFER command to the DEVICE, and if there is a
15 response either decodes it, prints it in hexadecimal or sends it in
16 binary to stdout. If a response is received for a "descriptor" mode
17 then, in the absence of --hex and --raw, it is decoded. Response for
18 non-descriptor modes are output in hexadecimal unless the --raw option
19 is given.
20 This utility may be called without a DEVICE but with a --inhex=FN
22 option instead. FN is expected to be a file name (or '-' for stdin).
23 The contents of the file (or stdin stream) is assumed to be hexadecimal
24 (or binary) data that represents a SCSI READ BUFFER command response
25 and is decoded as such.
26
28 Arguments to long options are mandatory for short options as well.
29 -h, --help
31 output the usage message then exit. If used multiple times also
32 prints the mode names and their acronyms.
33 -H, --hex
35 output the response in hexadecimal. When given twice the
36 response is output in hex with the corresponding representation
37 in ASCII to the right of each line.
38 -i, --id=ID
40 this option sets the buffer id field in the cdb. ID is a value
41 between 0 (default) and 255 inclusive.
42 -I, --inhex=FN
44 FN is expected to be a file name (or '-' for stdin) which con‐
45 tains ASCII hexadecimal or binary representing a READ BUFFER
46 response. If known this utility will then decode that response.
47 It is preferable to also supply the --mode=MO and --specific=MS
48 options, since these are not present in the response. The hexa‐
49 decimal should be arranged as 1 or 2 digits representing a byte
50 each of which is whitespace or comma separated. Anything from
51 and including a hash mark to the end of line is ignored. If the
52 --raw option is also given then FN is treated as binary.
53 -l, --length=LEN
55 where LEN is the length, in bytes, that is placed in the "allo‐
56 cation length" field in the cdb. The default value is 4 (bytes).
57 The device may respond with less bytes.
58 -m, --mode=MO
60 this option sets the mode field in the cdb. MO is a value
61 between 0 (default) and 31 inclusive. Alternatively an abbrevia‐
62 tion can be given. See the MODES section below. To list the
63 available mode abbreviations use an invalid one (e.g.
64 '--mode=xxx'). As an example, to fetch the read buffer descrip‐
65 tor give '--mode=desc' .
66 -o, --offset=OFF
68 this option sets the buffer offset field in the cdb. OFF is a
69 value between 0 (default) and 2**24-1 . It is a byte offset.
70 -r, --raw
72 if a response is received then it is sent in binary to stdout.
73 -R, --readonly
75 open the DEVICE read-only (e.g. in Unix with the O_RDONLY flag).
76 The default is to open it read-write.
77 -S, --specific=MS
79 this option sets the mode specific field in the cdb. MS is a
80 value between 0 and 7 as this is a 3 bit field.
81 -v, --verbose
83 increase the level of verbosity, (i.e. debug output).
84 -V, --version
86 print the version string and then exit.
87
89 Following is a list of READ BUFFER command settings for the MODE field.
90 First is an acronym accepted by the MO argument of this utility. Fol‐
91 lowing the acronym in square brackets are the corresponding decimal and
92 hex values that may also be given for MO. The following are listed in
93 numerical order.
94 hd [0, 0x0]
96 Combined header and data (obsolete in SPC-4).
97 vendor [1, 0x1]
99 Vendor specific.
100 data [2, 0x2]
102 Data.
103 desc [3, 0x3]
105 Descriptor: yields 4 bytes that contain an offset boundary field
106 (1 byte) and buffer capacity (3 bytes).
107 echo [10, 0xa]
109 Read data from echo buffer (was called "Echo buffer" in SPC-3).
110 echo_desc [11, 0xb]
112 Echo buffer descriptor: yields 4 bytes of which the last (low‐
113 est) 13 bits represent the echo buffer capacity. The maximum
114 echo buffer size is 4096 bytes.
115 rd_microc_st [15, 0xf]
117 Read microcode status. Added in spc5r20 .
118 en_ex [26, 0x1a]
120 Enable expander communications protocol and Echo buffer. Made
121 obsolete in SPC-4.
122 err_hist [28, 0x1c]
124 Error history. Introduced in SPC-4.
125
127 All numbers given with options are assumed to be decimal. Alterna‐
128 tively numerical values can be given in hexadecimal preceded by either
129 "0x" or "0X" (or has a trailing "h" or "H").
130
132 The exit status of sg_read_buffer is 0 when it is successful. Otherwise
133 see the sg3_utils(8) man page.
134
136 Written by Luben Tuikov and Douglas Gilbert.
137
139 Report bugs to <dgilbert at interlog dot com>.
140
142 Copyright © 2006-2019 Luben Tuikov and Douglas Gilbert
143 This software is distributed under a FreeBSD license. There is NO war‐
144 ranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PUR‐
145 POSE.
146
148 sg_write_buffer(sg3_utils)
149sg3_utils-1.45 May 2019 SG_READ_BUFFER(8)