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diff --git a/runtime/doc/xxd.man b/runtime/doc/xxd.man new file mode 100644 index 0000000..607db8a --- /dev/null +++ b/runtime/doc/xxd.man @@ -0,0 +1,270 @@ +XXD(1) General Commands Manual 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. + + -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 option only applies to hex‐ + dump, 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 sup‐ + press grouping. <Bytes> defaults to 2 in normal mode, 4 in lit‐ + tle-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 defini‐ + tion 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 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. + 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 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 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 <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) |