man > sg_read_buffer(8)

SG_READ_BUFFER(8)                             SG3_UTILS                            SG_READ_BUFFER(8)

NAME
       sg_read_buffer - send SCSI READ BUFFER command

SYNOPSIS
       sg_read_buffer  [--help]  [--hex]  [--id=ID]  [--inhex=FN] [--length=LEN] [--mode=MO] [--off‐
       set=OFF] [--raw] [--readonly] [--specific=MS] [--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.

       This utility may be called without a DEVICE but with a --inhex=FN option instead. FN  is  ex‐
       pected  to  be  a file name (or '-' for stdin). The contents of the file (or stdin stream) is
       assumed to be hexadecimal (or binary) data that represents a SCSI  READ  BUFFER  command  re‐
       sponse and is decoded as such.

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.

       -I, --inhex=FN
              FN  is  expected to be a file name (or '-' for stdin) which contains ASCII hexadecimal
              or binary representing a READ BUFFER response. If known this utility will then  decode
              that  response.  It  is  preferable to also supply the --mode=MO and --specific=MS op‐
              tions, since these are not present in the response. The hexadecimal should be arranged
              as 1 or 2 digits representing a byte each of which is whitespace or  comma  separated.
              Anything  from  and  including a hash mark to the end of line is ignored. If the --raw
              option is also given then FN is treated as binary.

       -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 (de‐
              fault) 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.

       -S, --specific=MS
              this  option sets the mode specific field in the cdb. MS is a value between 0 and 7 as
              this is a 3 bit field.

       -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.

       rd_microc_st  [15, 0xf]
              Read microcode status. Added in spc5r20 .

       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 © 2006-2019 Luben Tuikov and Douglas Gilbert
       This software is distributed under a FreeBSD license. There is NO warranty; not even for MER‐
       CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO
       sg_write_buffer(sg3_utils)

sg3_utils-1.45                                May 2019                             SG_READ_BUFFER(8)