# phpman > man > XXD(1) > **TLDR:** Create a hexadecimal representation (hexdump) from a binary file, or vice-versa. > - Generate a hexdump from a binary file and display the output: `xxd {{input_file}}` - Generate a hexdump from a binary file and save it as a text file: `xxd {{input_file}} {{output_file}}` - Display a more compact output, replacing consecutive zeros (if any) with a star: `xxd {{-a|-autoskip}} {{input_file}}` - Display the output with 10 columns of one octet (byte) each: `xxd {{-c|-cols}} {{10}} {{input_file}}` - Display output only up to a length of 32 bytes: `xxd {{-l|-len}} {{32}} {{input_file}}` - Display the output in plain mode, without any gaps between the columns: `xxd {{-p|-postscript}} {{input_file}}` - Revert a plaintext hexdump back into binary, and save it as a binary file: `xxd {{-r|-revert}} {{-p|-postscript}} {{input_file}} {{output_file}}` *Source: tldr-pages* --- [XXD(1)](https://www.chedong.com/phpMan.php/man/XXD/1/markdown) General Commands Manual [XXD(1)](https://www.chedong.com/phpMan.php/man/XXD/1/markdown) ## 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)](https://www.chedong.com/phpMan.php/man/uuencode/1/markdown) and [**uudecode**(1)](https://www.chedong.com/phpMan.php/man/uudecode/1/markdown) it allows the transmis‐ sion of binary data in a `mail-safe' ASCII representation, but has the advantage of decoding to standard output. Moreover, it can be used to perform binary file patching. ## OPTIONS If no _infile_ is given, standard input is read. If _infile_ is specified as a `**-**' character, then input is taken from standard 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 followed 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 hexdump. This option writes octets as eight digits "1"s and "0"s instead of a normal hexadecimal dump. Each line is pre‐ ceded by a line number in hexadecimal and followed by an ascii (or ebcdic) representa‐ tion. The command line switches -r, -p, -i do not work with this mode. _-c_ _cols_ | _-cols_ _cols_ Format <_cols_> octets per line. Default 16 (-i: 12, -ps: 30, -b: 6). Max 256. _-C_ | _-capitalize_ Capitalize variable names in C include file style, when using -i. _-E_ | _-EBCDIC_ Change the character encoding in the righthand column from ASCII to EBCDIC. This does not change the hexadecimal representation. The option is meaningless in combinations with -r, -p or -i. _-e_ Switch to little-endian hexdump. This option treats byte groups as words in little- endian byte order. The default grouping of 4 bytes may be changed using _-g_. This op‐ tion only applies to hexdump, leaving the ASCII (or EBCDIC) representation unchanged. The command line switches -r, -p, -i do not work with this mode. _-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, _4_ in little-endian 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. _-o_ _offset_ Add <_offset_> to the displayed file position. _-p_ | _-ps_ | _-postscript_ | _-plain_ 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 layout. 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 rel‐ ative 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 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)](https://www.chedong.com/phpMan.php/man/lseek/2/markdown) 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 everything on the input line after read‐ ing 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 hexdump 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_ and _%_ _xxd_ _-i_ _<_ _file_ _xxd_ _-s_ _+seek_ may be different from _xxd_ _-s_ _seek_, as [lseek(2)](https://www.chedong.com/phpMan.php/man/lseek/2/markdown) 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)](https://www.chedong.com/phpMan.php/man/strace/1/markdown) or [truss(1)](https://www.chedong.com/phpMan.php/man/truss/1/markdown), 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 20 octets per line. _%_ _xxd_ _-l_ _120_ _-ps_ _-c_ _20_ _xxd.1_ 2e54482058584420312022417567757374203139 39362220224d616e75616c207061676520666f72 20787864220a2e5c220a2e5c222032317374204d 617920313939360a2e5c22204d616e2070616765 20617574686f723a0a2e5c2220202020546f6e79 204e7567656e74203c746f6e79407363746e7567 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 _ _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 ............ * 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)](https://www.chedong.com/phpMan.php/man/vim/1/markdown)** to hexdump a region marked between `a' and `z'. _:'a,'z!xxd_ Use xxd as a filter within an editor such as [**vim(1)](https://www.chedong.com/phpMan.php/man/vim/1/markdown)** to recover a binary hexdump marked be‐ tween `a' and `z'. _:'a,'z!xxd_ _-r_ Use xxd as a filter within an editor such as [**vim(1)](https://www.chedong.com/phpMan.php/man/vim/1/markdown)** 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)](https://www.chedong.com/phpMan.php/man/uuencode/1/markdown), [uudecode(1)](https://www.chedong.com/phpMan.php/man/uudecode/1/markdown), [patch(1)](https://www.chedong.com/phpMan.php/man/patch/1/markdown) ## 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 <> 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. Manual page for xxd August 1996 [XXD(1)](https://www.chedong.com/phpMan.php/man/XXD/1/markdown)