[ новости /+++ | форум | теги | ]

NAME
     xxd - make a hexdump or do the reverse.

SYNOPSIS
     xxd -h[elp]
     xxd [options] [infile [outfile]]
     xxd -r[evert] [options] [infile [outfile]]

DESCRIPTION
     xxd creates a hex dump of a given file  or  standard  input.
     It  can  also convert a hex dump back to its original binary
     form.   Like  uuencode(1)  and  uudecode(1)  it  allows  the
     transmission of binary data in a `mail-safe' ASCII represen-
     tation, but has the advantage of decoding to  standard  out-
     put.  Moreover, it can be used to perform binary file patch-
     ing.

OPTIONS
     If no infile is given, standard input is read.  If infile is
     specified as a `-' character, then input is taken from stan-
     dard input.  If no outfile is given (or a `-'  character  is
     in its place), results are sent to standard output.

     Note that a "lazy" parser is used which does not  check  for
     more than the first option letter, unless the option is fol-
     lowed by a parameter.  Spaces between a single option letter
     and  its  parameter are optional.  Parameters to options can
     be specified in  decimal,  hexadecimal  or  octal  notation.
     Thus-c8, -c 8, -c 010 and -cols 8 are all equivalent.

     -a | -autoskip
          toggle  autoskip:  A  single  '*'  replaces  nul-lines.
          Default off.

     -b | -bits
          Switch to bits (binary digits) dump, rather  than  hex-
          dump.   This  option writes octets as eight digits "1"s
          and "0"s instead of a  normal  hexacecimal  dump.  Each
          line  is  preceded  by a line number in hexadecimal and
          followed by an ascii (or  ebcdic)  representation.  The
          command  line switches -r, -p, -i do not work with this
          mode.

     -c cols | -cols cols
          -c cols | -cols cols format  <cols>  octets  per  line.
          Default 16 (-i: 12, -ps: 30, -b: 6). Max 256.

     -E | -EBCDIC
          Change the character encoding in the  righthand  column
          from ASCII to EBCDIC.  This does not change the hexade-
          cimal representation. The option is meaningless in com-
          binations with -r, -p or -i.

     -g bytes | -groupsize bytes
          seperate the output of every  <bytes>  bytes  (two  hex
          characters  or  eight bit-digits each) by a whitespace.
          Specify -g 0 to suppress grouping.  <Bytes> defaults to
          2 in normal mode and 1 in bits mode.  Grouping does not
          apply to postscript or include style.

     -h | -help
          print a summary of available commands and exit.  No hex
          dumping is performed.

     -i | -include
          output in C include file style. A complete static array
          definition  is  written  (named  after the input file),
          unless xxd reads from stdin.

     -l len | -len len
          stop after writing <len> octets.

     -p | -ps | -postscript |
          output in postscript  continuous  hexdump  style.  Also
          known as plain hexdump style.

     -r | -revert
          reverse operation:  convert  (or  patch)  hexdump  into
          binary.   If not writing to stdout, xxd writes into its
          output file without truncating it. Use the  combination
          -r  -p  to  read  plain  hexadecimal dumps without line
          number information and without a particular column lay-
          out.  Additional Whitespace and line-breaks are allowed
          anywhere.

     -seek offset
          When used after -r : revert with <offset> added to file
          positions found in hexdump.

     -s [+][-]seek
          start at <seek> bytes abs. (or rel.) infile offset.   +
          indicates  that  the  seek  is  relative to the current
          stdin file position (meaningless when not reading  from
          stdin).   - indicates that the seek should be that many
          characters from the end of the input  (or  if  combined
          with
           + : before the current stdin file position).   Without
          -s option, xxd starts at the current file position.

     -u   use upper case hex letters. Default is lower case.

     -v | -version
          show version string.


CAVEATS
     xxd -r has some builtin magic while evaluating  line  number
     information.   If  the  ouput  file  is  seekable,  then the
     linenumbers at the start of each hexdump line may be out  of
     order,  lines may be missing, or overlapping. In these cases
     xxd will lseek(2) to the next position. If the  output  file
     is not seekable, only gaps are allowed, which will be filled
     by null-bytes.

     xxd -r never generates parse  errors.  Garbage  is  silently
     skipped.

     When editing hexdumps, please note that xxd -r skips  every-
     thing on the input line after reading enough columns of hex-
     adecimal data (see option -c). This also means, that changes
     to  the  printable  ascii  (or  ebcdic)  columns  are always
     ignored. Reverting a plain  (or  postscript)  style  hexdump
     with  xxd  -r  -p  does  not depend on the correct number of
     columns. Here an thing that looks like a pair of  hex-digits
     is interpreted.

     Note the difference between
     % xxd -i file
     and
     % xxd -i < file

     xxd -s +seek may be different from xxd -s seek , as lseek(2)
     is  used to "rewind" input.  A '+' makes a difference if the
     input source is stdin, and if stdin's file position  is  not
     at  the  start  of  the  file by the time xxd is started and
     given its input.  The following examples may help to clarify
     (or further confuse!)...

     Rewind stdin before reading; needed because  the  `cat'  has
     already read to the end of stdin.
     % sh -c 'cat > plain_copy; xxd -s 0 > hex_copy' < file

     Hexdump from file position 0x480 (=1024+128)  onwards.   The
     `+'  sign means "relative to the current position", thus the
     `128' adds to the 1k where dd left off.
     % sh -c 'dd of=plain_snippet bs=1k count=1; xxd  -s  +128  >
     hex_snippet' < file

     Hexdump from file position 0x100 ( = 1024-768) on.
     % sh -c 'dd of=plain_snippet bs=1k count=1; xxd -s  +-768  >
     hex_snippet' < file

     However, this is a rare situation and  the  use  of  `+'  is
     rarely  needed.  the author prefers to monitor the effect of
     xxd with strace(1) or truss(1), whenever -s is used.


EXAMPLES
     Print everything but the first three lines (hex 0x30  bytes)
     of file
     % xxd -s 0x30 file

     Print 3 lines (hex 0x30 bytes) from the end of file
     % xxd -s -0x30 file

     Print 120 bytes as continuous hexdump  with  40  octets  per
     line.
     % xxd -l 120 -ps -c 20 xxd.1
     2e544820585844203120224d616e75616c207061
     676520666f7220787864220a2e5c220a2e5c2220
     32317374204d617920313939360a2e5c22204d61
     6e207061676520617574686f723a0a2e5c222020
     2020546f6e79204e7567656e74203c746f6e7940
     7363746e7567656e2e7070702e67752e6564752e

     Hexdump the first 120 bytes of this man page with 12  octets
     per line.
     % xxd -l 120 -c 12 xxd.1
     0000000: 2e54 4820 5858 4420 3120 224d  .TH XXD 1 "M
     000000c: 616e 7561 6c20 7061 6765 2066  anual page f
     0000018: 6f72 2078 7864 220a 2e5c 220a  or xxd"..\".
     0000024: 2e5c 2220 3231 7374 204d 6179  .\" 21st May
     0000030: 2031 3939 360a 2e5c 2220 4d61   1996..\" Ma
     000003c: 6e20 7061 6765 2061 7574 686f  n page autho
     0000048: 723a 0a2e 5c22 2020 2020 546f  r:..\"    To
     0000054: 6e79 204e 7567 656e 7420 3c74  ny Nugent <t
     0000060: 6f6e 7940 7363 746e 7567 656e  ony@sctnugen
     000006c: 2e70 7070 2e67 752e 6564 752e  .ppp.gu.edu.

     Display just the date from the file xxd.1
     % xxd -s 0x28 -l 12 -c 12 xxd.1
     0000028: 3231 7374 204d 6179 2031 3939  21st May 199

     Copy input_file to output_file  and  prepend  100  bytes  of
     value 0x00.
     % xxd input_file | xxd -r -s 100 > output_file

     Patch the date in the file xxd.1
     % echo '0000029: 3574 68' | xxd -r - xxd.1
     % xxd -s 0x28 -l 12 -c 12 xxd.1
     0000028: 3235 7468 204d 6179 2031 3939  25th May 199

     Create a 65537 byte file with all bytes 0x00, except for the
     last one which is 'A' (hex 0x41).
     % echo '010000: 41' | xxd -r > file

     Hexdump this file with autoskip.
     % xxd -a -c 12 file
     0000000: 0000 0000 0000 0000 0000 0000  ............
     *
     000fffc: 0000 0000 40                   ....A

     Create a 1 byte file containing a single 'A' character.  The
     number  after  '-r  -s' adds to the linenumbers found in the
     file; in effect, the leading bytes are suppressed.
     % echo '010000: 41' | xxd -r -s -0x10000 > file

     Use xxd as a filter within an editor such as vim(1) to  hex-
     dump a region marked between `a' and `z'.
     :'a,'z!xxd

     Use xxd as a filter within  an  editor  such  as  vim(1)  to
     recover a binary hexdump marked between `a' and `z'.
     :'a,'z!xxd -r

     Use xxd as a filter within  an  editor  such  as  vim(1)  to
     recover  one  line  of  a hexdump.  Move the cursor over the
     line and type:
     !!xxd -r

     Read single characters from a serial line
     % xxd -c1 < /dev/term/b &
     % stty < /dev/term/b -echo -opost -isig -icanon min 1
     % echo -n foo > /dev/term/b

RETURN VALUES
     The following error values are returned:

     0    no errors encountered.

     -1   operation not supported ( xxd -r -i still impossible).

     1    error while parsing options.

     2    problems with input file.

     3    problems with output file.

     4,5  desired seek position is unreachable.

SEE ALSO
     uuencode(1), uudecode(1), patch(1)

WARNINGS
     The  tools  weirdness  matches  its  creators  brain.    Use
     entirely  at  your  own risk. Copy files. Trace it. Become a
     wizard.

VERSION
     This manual page documents xxd version 1.7

AUTHOR
     (c) 1990-1997 by Juergen Weigert
     <jnweiger@informatik.uni-erlangen.de>

     Distribute freely and credit me,
     make money and share with me,
     lose money and don't ask me.

     Manual page started by Tony Nugent
     <tony@sctnugen.ppp.gu.edu.au> <T.Nugent@sct.gu.edu.au>
     Small changes by Bram Moolenaar.  Edited by Juergen Weigert.

Партнёры:

Хостинг: