| XXD(1) XXD(1) |
| |
| |
| |
| 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 representation, but has the advantage of decoding to stan- |
| dard 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 preceded 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. |
| |
| -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. |
| |
| -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 sup- |
| press 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 defini- |
| tion is written (named after the input file), unless xxd reads |
| from stdin. |
| |
| -l len | -len len |
| stop after writing <len> octets. |
| |
| -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 hexadeci- |
| mal dumps without line number information and without a particu- |
| lar 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. + fRindi- |
| cates that the seek is relative to the current stdin file posi- |
| tion (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 over- |
| lapping. 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 everything 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 |
| hexdump with xxd -r -p does not depend on the correct number of col- |
| umns. Here anything that looks like a pair of hex-digits is inter- |
| preted. |
| |
| 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 |
| 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 <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 ............ |
| * |
| 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 hexdump 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. |
| |
| |
| |
| |
| Manual page for xxd August 1996 XXD(1) |