1.\" Copyright (c) 1989, 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.Dd June 29, 2020 29.Dt HEXDUMP 1 30.Os 31.Sh NAME 32.Nm hexdump , hd 33.Nd ASCII, decimal, hexadecimal, octal dump 34.Sh SYNOPSIS 35.Nm 36.Op Fl bcCdovx 37.Op Fl e Ar format_string 38.Op Fl f Ar format_file 39.Op Fl n Ar length 40.Bk -words 41.Op Fl s Ar offset 42.Ek 43.Ar 44.Nm hd 45.Op Fl bcdovx 46.Op Fl e Ar format_string 47.Op Fl f Ar format_file 48.Op Fl n Ar length 49.Bk -words 50.Op Fl s Ar offset 51.Ek 52.Ar 53.Sh DESCRIPTION 54The 55.Nm 56utility is a filter which displays the specified files, or 57the standard input, if no files are specified, in a user specified 58format. 59.Pp 60The options are as follows: 61.Bl -tag -width indent 62.It Fl b 63.Em One-byte octal display . 64Display the input offset in hexadecimal, followed by sixteen 65space-separated, three column, zero-filled, bytes of input data, 66in octal, per line. 67.It Fl c 68.Em One-byte character display . 69Display the input offset in hexadecimal, followed by sixteen 70space-separated, three column, space-filled, characters of input 71data per line. 72.It Fl C 73.Em Canonical hex+ASCII display . 74Display the input offset in hexadecimal, followed by sixteen 75space-separated, two column, hexadecimal bytes, followed by the 76same sixteen bytes in %_p format enclosed in ``|'' characters. 77.Pp 78Calling the command 79.Nm hd 80implies this option. 81.It Fl d 82.Em Two-byte decimal display . 83Display the input offset in hexadecimal, followed by eight 84space-separated, five column, zero-filled, two-byte units 85of input data, in unsigned decimal, per line. 86.It Fl e Ar format_string 87Specify a format string to be used for displaying data. 88.It Fl f Ar format_file 89Specify a file that contains one or more newline separated format strings. 90Empty lines and lines whose first non-blank character is a hash mark 91.Pf ( Cm \&# ) 92are ignored. 93.It Fl n Ar length 94Interpret only 95.Ar length 96bytes of input. 97.It Fl o 98.Em Two-byte octal display . 99Display the input offset in hexadecimal, followed by eight 100space-separated, six column, zero-filled, two byte quantities of 101input data, in octal, per line. 102.It Fl s Ar offset 103Skip 104.Ar offset 105bytes from the beginning of the input. 106By default, 107.Ar offset 108is interpreted as a decimal number. 109With a leading 110.Cm 0x 111or 112.Cm 0X , 113.Ar offset 114is interpreted as a hexadecimal number, 115otherwise, with a leading 116.Cm 0 , 117.Ar offset 118is interpreted as an octal number. 119Appending the character 120.Cm b , 121.Cm k , 122or 123.Cm m 124to 125.Ar offset 126causes it to be interpreted as a multiple of 127.Li 512 , 128.Li 1024 , 129or 130.Li 1048576 , 131respectively. 132.It Fl v 133Cause 134.Nm 135to display all input data. 136Without the 137.Fl v 138option, any number of groups of output lines, which would be 139identical to the immediately preceding group of output lines (except 140for the input offsets), are replaced with a line comprised of a 141single asterisk. 142.It Fl x 143.Em Two-byte hexadecimal display . 144Display the input offset in hexadecimal, followed by eight, space 145separated, four column, zero-filled, two-byte quantities of input 146data, in hexadecimal, per line. 147.El 148.Pp 149For each input file, 150.Nm 151sequentially copies the input to standard output, transforming the 152data according to the format strings specified by the 153.Fl e 154and 155.Fl f 156options, in the order that they were specified. 157.Ss Formats 158A format string contains any number of format units, separated by 159whitespace. 160A format unit contains up to three items: an iteration count, a byte 161count, and a format. 162.Pp 163The iteration count is an optional positive integer, which defaults to 164one. 165Each format is applied iteration count times. 166.Pp 167The byte count is an optional positive integer. 168If specified it defines the number of bytes to be interpreted by 169each iteration of the format. 170.Pp 171If an iteration count and/or a byte count is specified, a single slash 172must be placed after the iteration count and/or before the byte count 173to disambiguate them. 174Any whitespace before or after the slash is ignored. 175.Pp 176The format is required and must be surrounded by double quote 177(" ") marks. 178It is interpreted as a fprintf-style format string (see 179.Xr fprintf 3 ) , 180with the 181following exceptions: 182.Bl -bullet -offset indent 183.It 184An asterisk (*) may not be used as a field width or precision. 185.It 186A byte count or field precision 187.Em is 188required for each ``s'' conversion 189character (unlike the 190.Xr fprintf 3 191default which prints the entire string if the precision is unspecified). 192.It 193The conversion characters ``h'', ``l'', ``n'', ``p'' and ``q'' are 194not supported. 195.It 196The single character escape sequences 197described in the C standard are supported: 198.Bd -ragged -offset indent -compact 199.Bl -column <alert_character> 200.It "NUL \e0" 201.It "<alert character> \ea" 202.It "<backspace> \eb" 203.It "<form-feed> \ef" 204.It "<newline> \en" 205.It "<carriage return> \er" 206.It "<tab> \et" 207.It "<vertical tab> \ev" 208.El 209.Ed 210.El 211.Pp 212The 213.Nm 214utility also supports the following additional conversion strings: 215.Bl -tag -width Fl 216.It Cm \&_a Ns Op Cm dox 217Display the input offset, cumulative across input files, of the 218next byte to be displayed. 219The appended characters 220.Cm d , 221.Cm o , 222and 223.Cm x 224specify the display base 225as decimal, octal or hexadecimal respectively. 226.It Cm \&_A Ns Op Cm dox 227Identical to the 228.Cm \&_a 229conversion string except that it is only performed 230once, when all of the input data has been processed. 231.It Cm \&_c 232Output characters in the default character set. 233Nonprinting characters are displayed in three character, zero-padded 234octal, except for those representable by standard escape notation 235(see above), 236which are displayed as two character strings. 237.It Cm _p 238Output characters in the default character set. 239Nonprinting characters are displayed as a single 240.Dq Cm \&. . 241.It Cm _u 242Output US ASCII 243characters, with the exception that control characters are 244displayed using the following, lower-case, names. 245Characters greater than 0xff, hexadecimal, are displayed as hexadecimal 246strings. 247.Bl -column 000_nu 001_so 002_st 003_et 004_eo 248.It "000 NUL" Ta "001 SOH" Ta "002 STX" Ta "003 ETX" Ta "004 EOT" Ta "005 ENQ" 249.It "006 ACK" Ta "007 BEL" Ta "008 BS" Ta "009 HT" Ta "00A LF" Ta "00B VT" 250.It "00C FF" Ta "00D CR" Ta "00E\ SO" Ta "00F SI" Ta "010 DLE" Ta "011 DC1" 251.It "012 DC2" Ta "013 DC3" Ta "014 DC4" Ta "015\ NAK" Ta "016 SYN" Ta "017 ETB" 252.It "018 CAN" Ta "019 EM" Ta "01A SUB" Ta "01B ESC" Ta "01C FS" Ta "01D GS" 253.It "01E RS" Ta "01F US" Ta "07F DEL" Ta \& Ta \& Ta \& 254.El 255.El 256.Pp 257The default and supported byte counts for the conversion characters 258are as follows: 259.Bl -tag -width "Xc,_Xc,_Xc,_Xc,_Xc,_Xc" -offset indent 260.It Li \&%_c , \&%_p , \&%_u , \&%c 261One byte counts only. 262.It Xo 263.Li \&%d , \&%i , \&%o , 264.Li \&%u , \&%X , \&%x 265.Xc 266Four byte default, one, two and four byte counts supported. 267.It Xo 268.Li \&%E , \&%e , \&%f , 269.Li \&%G , \&%g 270.Xc 271Eight byte default, four and twelve byte counts supported. 272.El 273.Pp 274The amount of data interpreted by each format string is the sum of the 275data required by each format unit, which is the iteration count times the 276byte count, or the iteration count times the number of bytes required by 277the format if the byte count is not specified. 278.Pp 279The input is manipulated in ``blocks'', where a block is defined as the 280largest amount of data specified by any format string. 281Format strings interpreting less than an input block's worth of data, 282whose last format unit both interprets some number of bytes and does 283not have a specified iteration count, have the iteration count 284incremented until the entire input block has been processed or there 285is not enough data remaining in the block to satisfy the format string. 286.Pp 287If, either as a result of user specification or 288.Nm 289modifying 290the iteration count as described above, an iteration count is 291greater than one, no trailing whitespace characters are output 292during the last iteration. 293.Pp 294It is an error to specify a byte count as well as multiple conversion 295characters or strings unless all but one of the conversion characters 296or strings is 297.Cm \&_a 298or 299.Cm \&_A . 300.Pp 301If, as a result of the specification of the 302.Fl n 303option or end-of-file being reached, input data only partially 304satisfies a format string, the input block is zero-padded sufficiently 305to display all available data (i.e., any format units overlapping the 306end of data will display some number of the zero bytes). 307.Pp 308Further output by such format strings is replaced by an equivalent 309number of spaces. 310An equivalent number of spaces is defined as the number of spaces 311output by an 312.Cm s 313conversion character with the same field width 314and precision as the original conversion character or conversion 315string but with any 316.Dq Li \&+ , 317.Dq \&\ \& , 318.Dq Li \&# 319conversion flag characters 320removed, and referencing a NULL string. 321.Pp 322If no format strings are specified, the default display is equivalent 323to specifying the 324.Fl x 325option. 326.Sh EXIT STATUS 327.Ex -std hexdump hd 328.Sh EXAMPLES 329Dump input in canonical (hex+ASCII) form: 330.Bd -literal -offset indent 331$ echo "FreeBSD: The power to serve" | hexdump -C 33200000000 46 72 65 65 42 53 44 3a 20 54 68 65 20 70 6f 77 |FreeBSD: The pow| 33300000010 65 72 20 74 6f 20 73 65 72 76 65 0a |er to serve.| 3340000001c 335.Ed 336.Pp 337Same as above but skipping the first 4 bytes of stdin and interpreting only 3 338bytes of input: 339.Bd -literal -offset indent 340$ echo "FreeBSD: The power to serve" | hexdump -C -s 4 -n 3 34100000004 42 53 44 |BSD| 34200000007 343.Ed 344.Pp 345Assuming a format file named 346.Pa format.txt 347with the following contents that specify a perusal format: 348.Bd -literal -offset indent 349"%06.6_ao " 12/1 "%3_u " 350"\et\et" "%_p " 351"\en" 352.Ed 353.Pp 354Dump input in canonical form using the format in 355.Pa format.txt : 356.Bd -literal -offset indent 357$ echo "FreeBSD" | hexdump -f format.txt -C 358000000 F r e e B S D lf F r e e B S D . 35900000000 46 72 65 65 42 53 44 0a |FreeBSD.| 36000000008 361.Ed 362.Pp 363Assuming a format file named 364.Pa format.txt 365with the following contents that simulate the 366.Fl x 367option: 368.Bd -literal -offset indent 369"%07.7_Ax\en" 370"%07.7_ax " 8/2 "%04x " "\en" 371.Ed 372.Pp 373Dump input in canonical form using the format in 374.Pa format.txt : 375.Bd -literal -offset indent 376$ echo "FreeBSD: The power to serve" | hexdump -f format.txt -C 3770000000 7246 6565 5342 3a44 5420 6568 7020 776f 37800000000 46 72 65 65 42 53 44 3a 20 54 68 65 20 70 6f 77 |FreeBSD: The pow| 3790000010 7265 7420 206f 6573 7672 0a65 38000000010 65 72 20 74 6f 20 73 65 72 76 65 0a |er to serve.| 3810000001c 382.Ed 383.Sh SEE ALSO 384.Xr od 1 385