1.\" $NetBSD: hexdump.1,v 1.24 2012/07/06 14:10:06 wiz Exp $ 2.\" 3.\" Copyright (c) 1989, 1990, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" from: @(#)hexdump.1 8.2 (Berkeley) 4/18/94 31.\" 32.Dd June 24, 2012 33.Dt HEXDUMP 1 34.Os 35.Sh NAME 36.Nm hexdump 37.Nd ascii, decimal, hexadecimal, octal dump 38.Sh SYNOPSIS 39.Nm 40.Op Fl bCcdovx 41.Op Fl e Ar format_string 42.Op Fl f Ar format_file 43.Op Fl n Ar length 44.Op Fl s Ar skip 45.Op Ar 46.Sh DESCRIPTION 47The 48.Nm 49utility is a filter which displays each specified 50.Ar file , 51or the standard input if no 52.Ar file 53arguments are specified, in a user specified 54format. 55.Pp 56The options are as follows: 57.Bl -tag -width Fl 58.It Fl b 59.Em One-byte octal display . 60Display the input offset in hexadecimal, followed by sixteen 61space-separated, three column, zero-filled, bytes of input data, 62in octal, per line. 63.It Fl C 64.Em Canonical hex+ASCII display . 65Display the input offset in hexadecimal, followed by sixteen 66space-separated, two column, hexadecimal bytes, followed by the 67same sixteen bytes in %_p format enclosed in 68.Sq | 69characters. 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 d 76.Em Two-byte decimal display . 77Display the input offset in hexadecimal, followed by eight 78space-separated, five column, zero-filled, two-byte units 79of input data, in unsigned decimal, per line. 80.It Fl e Ar format_string 81Specify a format string to be used for displaying data. 82.It Fl f Ar format_file 83Specify a file that contains one or more newline separated format strings. 84Empty lines and lines whose first non-blank character is a hash mark 85.Pq Sq # 86are ignored. 87.It Fl n Ar length 88Interpret only 89.Ar length 90bytes of input. 91.It Fl o 92.Em Two-byte octal display . 93Display the input offset in hexadecimal, followed by eight 94space-separated, six column, zero-filled, two byte quantities of 95input data, in octal, per line. 96.It Fl s Ar skip 97Skip 98.Ar skip 99bytes from the beginning of the input. 100By default, 101.Ar skip 102is interpreted as a decimal number. 103With a leading 104.Cm 0x 105or 106.Cm 0X , 107.Ar skip 108is interpreted as a hexadecimal number; 109otherwise, with a leading 110.Cm 0 , 111.Ar skip 112is interpreted as an octal number. 113Appending the character 114.Cm b , 115.Cm k , 116or 117.Cm m 118to 119.Ar skip 120causes it to be interpreted as a multiple of 121.Li 512 , 122.Li 1024 , 123or 124.Li 1048576 , 125respectively. 126.It Fl v 127The 128.Fl v 129option causes 130.Nm 131to display all input data. 132Without the 133.Fl v 134option, any number of groups of output lines, which would be 135identical to the immediately preceding group of output lines (except 136for the input offsets), are replaced with a line containing a 137single asterisk 138.Pq Sq \&* . 139.It Fl x 140.Em Two-byte hexadecimal display . 141Display the input offset in hexadecimal, followed by eight, space 142separated, four column, zero-filled, two-byte quantities of input 143data, in hexadecimal, per line. 144.El 145.Pp 146For each input file, 147.Nm 148sequentially copies the input to standard output, transforming the 149data according to the format strings specified by the 150.Fl e 151and 152.Fl f 153options, in the order that they were specified. 154.Ss Formats 155A format string contains any number of format units, separated by 156whitespace. 157A format unit contains up to three items: an iteration count, a byte 158count, and a format. 159.Pp 160The iteration count is an optional positive integer, which defaults to 161one. 162Each format is applied iteration count times. 163.Pp 164The byte count is an optional positive integer. 165If specified it defines the number of bytes to be interpreted by 166each iteration of the format. 167.Pp 168If an iteration count and/or a byte count is specified, a single slash 169.Pq Sq / 170must be placed after the iteration count and/or before the byte count 171to disambiguate them. 172Any whitespace before or after the slash is ignored. 173.Pp 174The format is required and must be surrounded by double quote 175.Pq Sq \&" 176marks. 177It is interpreted as a fprintf-style format string (see 178.Xr fprintf 3 ) , 179with the 180following exceptions: 181.Bl -bullet -offset indent 182.It 183An asterisk 184.Pq Sq \&* 185may not be used as a field width or precision. 186.It 187A byte count or field precision 188.Em is 189required for each 190.Sq s 191conversion 192character (unlike the 193.Xr fprintf 3 194default which prints the entire string if the precision is unspecified). 195.It 196The conversion characters 197.Sq h , 198.Sq l , 199.Sq n , 200.Sq p , 201and 202.Sq q 203are 204not supported. 205.It 206The single character escape sequences 207described in the C standard are supported: 208.Bd -ragged -offset indent -compact 209.Bl -column Xalert_characterX 210.It NUL \e0 211.It Aq alert character \ea 212.It Aq backspace \eb 213.It Aq form-feed \ef 214.It Aq newline \en 215.It Aq carriage return \er 216.It Aq tab \et 217.It Aq vertical tab \ev 218.El 219.Ed 220.El 221.Pp 222.Nm 223also supports the following additional conversion strings: 224.Bl -tag -width Fl 225.It Cm \&_a Ns Op Cm dox 226Display the input offset, cumulative across input files, of the 227next byte to be displayed. 228The appended characters 229.Cm d , 230.Cm o , 231and 232.Cm x 233specify the display base 234as decimal, octal or hexadecimal respectively. 235.It Cm \&_A Ns Op Cm dox 236Identical to the 237.Cm \&_a 238conversion string except that it is only performed 239once, when all of the input data has been processed. 240.It Cm \&_c 241Output characters in the default character set. 242Non-printing characters are displayed in three character, zero-padded 243octal, except for those representable by standard escape notation 244(see above), 245which are displayed as two character strings. 246.It Cm _p 247Output characters in the default character set. 248Non-printing characters are displayed as a single 249.Sq Cm \&. . 250.It Cm _u 251Output US ASCII characters, with the exception that control characters are 252displayed using the following, lower-case, names. 253Characters greater than 0xff, hexadecimal, are displayed as hexadecimal 254strings. 255.Bl -column \&000_nu \&001_so \&002_st \&003_et \&004_eo 256.It \&000\ nul Ta 001\ soh Ta 002\ stx Ta 003\ etx Ta 004\ eot Ta 005\ enq 257.It \&006\ ack Ta 007\ bel Ta 008\ bs Ta 009\ ht Ta 00A\ lf Ta 00B\ vt 258.It \&00C\ ff Ta 00D\ cr Ta 00E\ so Ta 00F\ si Ta 010\ dle Ta 011\ dc1 259.It \&012\ dc2 Ta 013\ dc3 Ta 014\ dc4 Ta 015\ nak Ta 016\ syn Ta 017\ etb 260.It \&018\ can Ta 019\ em Ta 01A\ sub Ta 01B\ esc Ta 01C\ fs Ta 01D\ gs 261.It \&01E\ rs Ta 01F\ us Ta 07F\ del 262.El 263.El 264.Pp 265The default and supported byte counts for the conversion characters 266are as follows: 267.Bl -tag -width "Xc,_Xc,_Xc,_Xc,_Xc,_Xc" -offset indent 268.It Li \&%_c , \&%_p , \&%_u , \&%c 269One byte counts only. 270.It Li \&%d , \&%i , \&%o , \&%u , \&%X , \&%x 271Four byte default, one, two, four and eight byte counts supported. 272.It Li \&%E , \&%e , \&%f , \&%G , \&%g 273Eight byte default, four byte counts supported. 274.El 275.Pp 276The amount of data interpreted by each format string is the sum of the 277data required by each format unit, which is the iteration count times the 278byte count, or the iteration count times the number of bytes required by 279the format if the byte count is not specified. 280.Pp 281The input is manipulated in 282.Dq blocks , 283where 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.Sq Li \&+ , 321.Sq \&\ \& , 322and 323.Sq Li \&# 324conversion flag characters 325removed, and referencing a 326.Dv NULL 327string. 328.Pp 329If no format strings are specified, the default display is equivalent 330to specifying the 331.Fl x 332option. 333.Sh EXIT STATUS 334.Ex -std 335.Sh EXAMPLES 336Display the input in perusal format: 337.Bd -literal -offset indent 338"%06.6_ao " 12/1 "%3_u " 339"\et\et" "%_p " 340"\en" 341.Ed 342.Pp 343Implement the 344.Fl x 345option: 346.Bd -literal -offset indent 347"%07.7_Ax\en" 348"%07.7_ax " 8/2 "%04x " "\en" 349.Ed 350.Sh SEE ALSO 351.Xr od 1 352