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.\" @(#)hexdump.1 8.2 (Berkeley) 4/18/94 29.\" $FreeBSD$ 30.\" 31.Dd October 29, 2014 32.Dt HEXDUMP 1 33.Os 34.Sh NAME 35.Nm hexdump , hd 36.Nd ASCII, decimal, hexadecimal, octal dump 37.Sh SYNOPSIS 38.Nm 39.Op Fl bcCdovx 40.Op Fl e Ar format_string 41.Op Fl f Ar format_file 42.Op Fl n Ar length 43.Bk -words 44.Op Fl s Ar offset 45.Ek 46.Ar 47.Nm hd 48.Op Fl bcdovx 49.Op Fl e Ar format_string 50.Op Fl f Ar format_file 51.Op Fl n Ar length 52.Bk -words 53.Op Fl s Ar offset 54.Ek 55.Ar 56.Sh DESCRIPTION 57The 58.Nm 59utility is a filter which displays the specified files, or 60the standard input, if no files are specified, in a user specified 61format. 62.Pp 63The options are as follows: 64.Bl -tag -width indent 65.It Fl b 66.Em One-byte octal display . 67Display the input offset in hexadecimal, followed by sixteen 68space-separated, three column, zero-filled, bytes of input data, 69in octal, per line. 70.It Fl c 71.Em One-byte character display . 72Display the input offset in hexadecimal, followed by sixteen 73space-separated, three column, space-filled, characters of input 74data per line. 75.It Fl C 76.Em Canonical hex+ASCII display . 77Display the input offset in hexadecimal, followed by sixteen 78space-separated, two column, hexadecimal bytes, followed by the 79same sixteen bytes in %_p format enclosed in ``|'' characters. 80.Pp 81Calling the command 82.Nm hd 83implies this option. 84.It Fl d 85.Em Two-byte decimal display . 86Display the input offset in hexadecimal, followed by eight 87space-separated, five column, zero-filled, two-byte units 88of input data, in unsigned decimal, per line. 89.It Fl e Ar format_string 90Specify a format string to be used for displaying data. 91.It Fl f Ar format_file 92Specify a file that contains one or more newline separated format strings. 93Empty lines and lines whose first non-blank character is a hash mark 94.Pf ( Cm \&# ) 95are ignored. 96.It Fl n Ar length 97Interpret only 98.Ar length 99bytes of input. 100.It Fl o 101.Em Two-byte octal display . 102Display the input offset in hexadecimal, followed by eight 103space-separated, six column, zero-filled, two byte quantities of 104input data, in octal, per line. 105.It Fl s Ar offset 106Skip 107.Ar offset 108bytes from the beginning of the input. 109By default, 110.Ar offset 111is interpreted as a decimal number. 112With a leading 113.Cm 0x 114or 115.Cm 0X , 116.Ar offset 117is interpreted as a hexadecimal number, 118otherwise, with a leading 119.Cm 0 , 120.Ar offset 121is interpreted as an octal number. 122Appending the character 123.Cm b , 124.Cm k , 125or 126.Cm m 127to 128.Ar offset 129causes it to be interpreted as a multiple of 130.Li 512 , 131.Li 1024 , 132or 133.Li 1048576 , 134respectively. 135.It Fl v 136Cause 137.Nm 138to display all input data. 139Without the 140.Fl v 141option, any number of groups of output lines, which would be 142identical to the immediately preceding group of output lines (except 143for the input offsets), are replaced with a line comprised of a 144single asterisk. 145.It Fl x 146.Em Two-byte hexadecimal display . 147Display the input offset in hexadecimal, followed by eight, space 148separated, four column, zero-filled, two-byte quantities of input 149data, in hexadecimal, per line. 150.El 151.Pp 152For each input file, 153.Nm 154sequentially copies the input to standard output, transforming the 155data according to the format strings specified by the 156.Fl e 157and 158.Fl f 159options, in the order that they were specified. 160.Ss Formats 161A format string contains any number of format units, separated by 162whitespace. 163A format unit contains up to three items: an iteration count, a byte 164count, and a format. 165.Pp 166The iteration count is an optional positive integer, which defaults to 167one. 168Each format is applied iteration count times. 169.Pp 170The byte count is an optional positive integer. 171If specified it defines the number of bytes to be interpreted by 172each iteration of the format. 173.Pp 174If an iteration count and/or a byte count is specified, a single slash 175must be placed after the iteration count and/or before the byte count 176to disambiguate them. 177Any whitespace before or after the slash is ignored. 178.Pp 179The format is required and must be surrounded by double quote 180(" ") marks. 181It is interpreted as a fprintf-style format string (see 182.Xr fprintf 3 ) , 183with the 184following exceptions: 185.Bl -bullet -offset indent 186.It 187An asterisk (*) may not be used as a field width or precision. 188.It 189A byte count or field precision 190.Em is 191required for each ``s'' conversion 192character (unlike the 193.Xr fprintf 3 194default which prints the entire string if the precision is unspecified). 195.It 196The conversion characters ``h'', ``l'', ``n'', ``p'' and ``q'' are 197not supported. 198.It 199The single character escape sequences 200described in the C standard are supported: 201.Bd -ragged -offset indent -compact 202.Bl -column <alert_character> 203.It "NUL \e0" 204.It "<alert character> \ea" 205.It "<backspace> \eb" 206.It "<form-feed> \ef" 207.It "<newline> \en" 208.It "<carriage return> \er" 209.It "<tab> \et" 210.It "<vertical tab> \ev" 211.El 212.Ed 213.El 214.Pp 215The 216.Nm 217utility also supports the following additional conversion strings: 218.Bl -tag -width Fl 219.It Cm \&_a Ns Op Cm dox 220Display the input offset, cumulative across input files, of the 221next byte to be displayed. 222The appended characters 223.Cm d , 224.Cm o , 225and 226.Cm x 227specify the display base 228as decimal, octal or hexadecimal respectively. 229.It Cm \&_A Ns Op Cm dox 230Identical to the 231.Cm \&_a 232conversion string except that it is only performed 233once, when all of the input data has been processed. 234.It Cm \&_c 235Output characters in the default character set. 236Nonprinting characters are displayed in three character, zero-padded 237octal, except for those representable by standard escape notation 238(see above), 239which are displayed as two character strings. 240.It Cm _p 241Output characters in the default character set. 242Nonprinting characters are displayed as a single 243.Dq Cm \&. . 244.It Cm _u 245Output US 246.Tn ASCII 247characters, with the exception that control characters are 248displayed using the following, lower-case, names. 249Characters greater than 0xff, hexadecimal, are displayed as hexadecimal 250strings. 251.Bl -column 000_nu 001_so 002_st 003_et 004_eo 252.It "000 NUL" Ta "001 SOH" Ta "002 STX" Ta "003 ETX" Ta "004 EOT" Ta "005 ENQ" 253.It "006 ACK" Ta "007 BEL" Ta "008 BS" Ta "009 HT" Ta "00A LF" Ta "00B VT" 254.It "00C FF" Ta "00D CR" Ta "00E\ SO" Ta "00F SI" Ta "010 DLE" Ta "011 DC1" 255.It "012 DC2" Ta "013 DC3" Ta "014 DC4" Ta "015\ NAK" Ta "016 SYN" Ta "017 ETB" 256.It "018 CAN" Ta "019 EM" Ta "01A SUB" Ta "01B ESC" Ta "01C FS" Ta "01D GS" 257.It "01E RS" Ta "01F US" Ta "07F DEL" Ta \& Ta \& Ta \& 258.El 259.El 260.Pp 261The default and supported byte counts for the conversion characters 262are as follows: 263.Bl -tag -width "Xc,_Xc,_Xc,_Xc,_Xc,_Xc" -offset indent 264.It Li \&%_c , \&%_p , \&%_u , \&%c 265One byte counts only. 266.It Xo 267.Li \&%d , \&%i , \&%o , 268.Li \&%u , \&%X , \&%x 269.Xc 270Four byte default, one, two and four byte counts supported. 271.It Xo 272.Li \&%E , \&%e , \&%f , 273.Li \&%G , \&%g 274.Xc 275Eight byte default, four and twelve byte counts supported. 276.El 277.Pp 278The amount of data interpreted by each format string is the sum of the 279data required by each format unit, which is the iteration count times the 280byte count, or the iteration count times the number of bytes required by 281the format if the byte count is not specified. 282.Pp 283The input is manipulated in ``blocks'', where a block is defined as the 284largest amount of data specified by any format string. 285Format strings interpreting less than an input block's worth of data, 286whose last format unit both interprets some number of bytes and does 287not have a specified iteration count, have the iteration count 288incremented until the entire input block has been processed or there 289is not enough data remaining in the block to satisfy the format string. 290.Pp 291If, either as a result of user specification or 292.Nm 293modifying 294the iteration count as described above, an iteration count is 295greater than one, no trailing whitespace characters are output 296during the last iteration. 297.Pp 298It is an error to specify a byte count as well as multiple conversion 299characters or strings unless all but one of the conversion characters 300or strings is 301.Cm \&_a 302or 303.Cm \&_A . 304.Pp 305If, as a result of the specification of the 306.Fl n 307option or end-of-file being reached, input data only partially 308satisfies a format string, the input block is zero-padded sufficiently 309to display all available data (i.e., any format units overlapping the 310end of data will display some number of the zero bytes). 311.Pp 312Further output by such format strings is replaced by an equivalent 313number of spaces. 314An equivalent number of spaces is defined as the number of spaces 315output by an 316.Cm s 317conversion character with the same field width 318and precision as the original conversion character or conversion 319string but with any 320.Dq Li \&+ , 321.Dq \&\ \& , 322.Dq Li \&# 323conversion flag characters 324removed, and referencing a NULL string. 325.Pp 326If no format strings are specified, the default display is equivalent 327to specifying the 328.Fl x 329option. 330.Sh EXIT STATUS 331.Ex -std hexdump hd 332.Sh EXAMPLES 333Display the input in perusal format: 334.Bd -literal -offset indent 335"%06.6_ao " 12/1 "%3_u " 336"\et\et" "%_p " 337"\en" 338.Ed 339.Pp 340Implement the \-x option: 341.Bd -literal -offset indent 342"%07.7_Ax\en" 343"%07.7_ax " 8/2 "%04x " "\en" 344.Ed 345.Sh SEE ALSO 346.Xr gdb 1 , 347.Xr od 1 348