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)