man pages section 1: User Commands

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Updated: July 2014

xxd (1)


xxd - make a hexdump or do the reverse.


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


User Commands                                              XXD(1)

     xxd - make a hexdump or do the reverse.

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

     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 trans-
     mission of binary data in a  `mail-safe'  ASCII  representa-
     tion,  but has the advantage of decoding to standard output.
     Moreover, it can be used to perform binary file patching.

     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 hexadecimal 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

     -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 hexa-
          decimal representation. The option  is  meaningless  in
          combinations with -r, -p or -i.

Manual page for xxd  Last change: August 1996                   1

User Commands                                              XXD(1)

     -g bytes | -groupsize bytes
          separate  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 num-
          ber information and without a particular column layout.
          Additional Whitespace and line-breaks are allowed  any-

     -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).  With-
          out -s option, xxd starts at the current file position.

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

     -v | -version
          show version string.


Manual page for xxd  Last change: August 1996                   2

User Commands                                              XXD(1)

     xxd  -r  has some builtin magic while evaluating line number
     information.  If the  output  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

     When editing hexdumps, please note that xxd -r skips  every-
     thing  on  the  input  line  after reading enough columns of
     hexadecimal 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 hex-
     dump with xxd -r -p does not depend on the correct number of
     columns. Here anything that looks like a pair of  hex-digits
     is interpreted.

     Note the difference between
     % xxd -i file
     % 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.


Manual page for xxd  Last change: August 1996                   3

User Commands                                              XXD(1)

     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  20  octets  per
     % xxd -l 120 -ps -c 20 xxd.1

     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 2241  .TH XXD 1 "A
     000000c: 7567 7573 7420 3139 3936 2220  ugust 1996"
     0000018: 224d 616e 7561 6c20 7061 6765  "Manual page
     0000024: 2066 6f72 2078 7864 220a 2e5c   for xxd"..\
     0000030: 220a 2e5c 2220 3231 7374 204d  "..\" 21st M
     000003c: 6179 2031 3939 360a 2e5c 2220  ay 1996..\"
     0000048: 4d61 6e20 7061 6765 2061 7574  Man page aut
     0000054: 686f 723a 0a2e 5c22 2020 2020  hor:..\"
     0000060: 546f 6e79 204e 7567 656e 7420  Tony Nugent
     000006c: 3c74 6f6e 7940 7363 746e 7567  <tony@sctnug

     Display just the date from the file xxd.1
     % xxd -s 0x36 -l 13 -c 13 xxd.1
     0000036: 3231 7374 204d 6179 2031 3939 36  21st May 1996

     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 "0000037: 3574 68" | xxd -r - xxd.1
     % xxd -s 0x36 -l 13 -c 13 xxd.1
     0000036: 3235 7468 204d 6179 2031 3939 36  25th May 1996

     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  ............

Manual page for xxd  Last change: August 1996                   4

User Commands                                              XXD(1)

     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'.

     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

     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   attributes(5)   for   descriptions  of  the  following

     |Availability   | editor/vim       |
     |Stability      | Uncommitted      |

Manual page for xxd  Last change: August 1996                   5

User Commands                                              XXD(1)

     uuencode(1), uudecode(1), patch(1)

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

     This manual page documents xxd version 1.7

     (c) 1990-1997 by Juergen Weigert

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

     Manual page started by Tony Nugent
     <> <>
     Small changes by Bram Moolenaar.  Edited by Juergen Weigert.

     This   software   was   built   from   source  available  at   The   original
     community  source  was  downloaded from

     Further information about this software can be found on  the
     open source community website at

Manual page for xxd  Last change: August 1996                   6