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. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)hexdump.1 8.2 (Berkeley) 4/18/94 33.\" $FreeBSD: src/usr.bin/hexdump/hexdump.1,v 1.9.2.9 2003/02/25 20:05:17 trhodes Exp $ 34.\" $DragonFly: src/usr.bin/hexdump/hexdump.1,v 1.4 2006/02/17 19:39:07 swildner Exp $ 35.\" 36.Dd April 18, 1994 37.Dt HEXDUMP 1 38.Os 39.Sh NAME 40.Nm hexdump , 41.Nm hd 42.Nd ASCII, decimal, hexadecimal, octal dump 43.Sh SYNOPSIS 44.Nm 45.Op Fl bcCdovx 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 skip 51.Ek 52.Ar 53.Nm hd 54.Op Fl bcdovx 55.Op Fl e Ar format_string 56.Op Fl f Ar format_file 57.Op Fl n Ar length 58.Bk -words 59.Op Fl s Ar skip 60.Ek 61.Ar 62.Sh DESCRIPTION 63The 64.Nm 65utility is a filter which displays the specified files, or 66the standard input, if no files are specified, in a user specified 67format. 68.Pp 69The options are as follows: 70.Bl -tag -width indent 71.It Fl b 72.Em One-byte octal display . 73Display the input offset in hexadecimal, followed by sixteen 74space-separated, three column, zero-filled, bytes of input data, 75in octal, per line. 76.It Fl c 77.Em One-byte character display . 78Display the input offset in hexadecimal, followed by sixteen 79space-separated, three column, space-filled, characters of input 80data per line. 81.It Fl C 82.Em Canonical hex+ASCII display . 83Display the input offset in hexadecimal, followed by sixteen 84space-separated, two column, hexadecimal bytes, followed by the 85same sixteen bytes in %_p format enclosed in ``|'' characters. 86.Pp 87Calling the command 88.Nm hd 89implies this option. 90.It Fl d 91.Em Two-byte decimal display . 92Display the input offset in hexadecimal, followed by eight 93space-separated, five column, zero-filled, two-byte units 94of input data, in unsigned decimal, per line. 95.It Fl e Ar format_string 96Specify a format string to be used for displaying data. 97.It Fl f Ar format_file 98Specify a file that contains one or more newline separated format strings. 99Empty lines and lines whose first non-blank character is a hash mark 100.Pf ( Cm \&# ) 101are ignored. 102.It Fl n Ar length 103Interpret only 104.Ar length 105bytes of input. 106.It Fl o 107.Em Two-byte octal display . 108Display the input offset in hexadecimal, followed by eight 109space-separated, six column, zero-filled, two byte quantities of 110input data, in octal, per line. 111.It Fl s Ar offset 112Skip 113.Ar offset 114bytes from the beginning of the input. 115By default, 116.Ar offset 117is interpreted as a decimal number. 118With a leading 119.Cm 0x 120or 121.Cm 0X , 122.Ar offset 123is interpreted as a hexadecimal number, 124otherwise, with a leading 125.Cm 0 , 126.Ar offset 127is interpreted as an octal number. 128Appending the character 129.Cm b , 130.Cm k , 131or 132.Cm m 133to 134.Ar offset 135causes it to be interpreted as a multiple of 136.Li 512 , 137.Li 1024 , 138or 139.Li 1048576 , 140respectively. 141.It Fl v 142Cause 143.Nm 144to display all input data. 145Without the 146.Fl v 147option, any number of groups of output lines, which would be 148identical to the immediately preceding group of output lines (except 149for the input offsets), are replaced with a line comprised of a 150single asterisk. 151.It Fl x 152.Em Two-byte hexadecimal display . 153Display the input offset in hexadecimal, followed by eight, space 154separated, four column, zero-filled, two-byte quantities of input 155data, in hexadecimal, per line. 156.El 157.Pp 158For each input file, 159.Nm 160sequentially copies the input to standard output, transforming the 161data according to the format strings specified by the 162.Fl e 163and 164.Fl f 165options, in the order that they were specified. 166.Ss Formats 167A format string contains any number of format units, separated by 168whitespace. 169A format unit contains up to three items: an iteration count, a byte 170count, and a format. 171.Pp 172The iteration count is an optional positive integer, which defaults to 173one. 174Each format is applied iteration count times. 175.Pp 176The byte count is an optional positive integer. 177If specified it defines the number of bytes to be interpreted by 178each iteration of the format. 179.Pp 180If an iteration count and/or a byte count is specified, a single slash 181must be placed after the iteration count and/or before the byte count 182to disambiguate them. 183Any whitespace before or after the slash is ignored. 184.Pp 185The format is required and must be surrounded by double quote 186(" ") marks. 187It is interpreted as a fprintf-style format string (see 188.Xr fprintf 3 ) , 189with the 190following exceptions: 191.Bl -bullet -offset indent 192.It 193An asterisk (*) may not be used as a field width or precision. 194.It 195A byte count or field precision 196.Em is 197required for each ``s'' conversion 198character (unlike the 199.Xr fprintf 3 200default which prints the entire string if the precision is unspecified). 201.It 202The conversion characters ``h'', ``l'', ``n'', ``p'' and ``q'' are 203not supported. 204.It 205The single character escape sequences 206described in the C standard are supported: 207.Bd -ragged -offset indent -compact 208.Bl -column <alert_character> 209.It "NUL \e0" 210.It "<alert character> \ea" 211.It "<backspace> \eb" 212.It "<form-feed> \ef" 213.It "<newline> \en" 214.It "<carriage return> \er" 215.It "<tab> \et" 216.It "<vertical tab> \ev" 217.El 218.Ed 219.El 220.Pp 221The 222.Nm 223utility also 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. 242Nonprinting 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. 248Nonprinting characters are displayed as a single 249.Dq Cm \&. . 250.It Cm _u 251Output US 252.Tn ASCII 253characters, with the exception that control characters are 254displayed using the following, lower-case, names. 255Characters greater than 0xff, hexadecimal, are displayed as hexadecimal 256strings. 257.Bl -column \&000_nu \&001_so \&002_st \&003_et \&004_eo 258.It "\&000\ NUL\t001\ SOH\t002\ STX\t003\ ETX\t004\ EOT\t005\ ENQ 259.It "\&006\ ACK\t007\ BEL\t008\ BS\t009\ HT\t00A\ LF\t00B\ VT 260.It "\&00C\ FF\t00D\ CR\t00E\ SO\t00F\ SI\t010\ DLE\t011\ DC1 261.It "\&012\ DC2\t013\ DC3\t014\ DC4\t015\ NAK\t016\ SYN\t017\ ETB 262.It "\&018\ CAN\t019\ EM\t01A\ SUB\t01B\ ESC\t01C\ FS\t01D\ GS 263.It "\&01E\ RS\t01F\ US\t0FF\ DEL 264.El 265.El 266.Pp 267The default and supported byte counts for the conversion characters 268are as follows: 269.Bl -tag -width "Xc,_Xc,_Xc,_Xc,_Xc,_Xc" -offset indent 270.It Li \&%_c , \&%_p , \&%_u , \&%c 271One byte counts only. 272.It Xo 273.Li \&%d , \&%i , \&%o , 274.Li \&%u , \&%X , \&%x 275.Xc 276Four byte default, one, two and four byte counts supported. 277.It Xo 278.Li \&%E , \&%e , \&%f , 279.Li \&%G , \&%g 280.Xc 281Eight byte default, four and twelve byte counts supported. 282.El 283.Pp 284The amount of data interpreted by each format string is the sum of the 285data required by each format unit, which is the iteration count times the 286byte count, or the iteration count times the number of bytes required by 287the format if the byte count is not specified. 288.Pp 289The input is manipulated in ``blocks'', where a block is defined as the 290largest amount of data specified by any format string. 291Format strings interpreting less than an input block's worth of data, 292whose last format unit both interprets some number of bytes and does 293not have a specified iteration count, have the iteration count 294incremented until the entire input block has been processed or there 295is not enough data remaining in the block to satisfy the format string. 296.Pp 297If, either as a result of user specification or 298.Nm 299modifying 300the iteration count as described above, an iteration count is 301greater than one, no trailing whitespace characters are output 302during the last iteration. 303.Pp 304It is an error to specify a byte count as well as multiple conversion 305characters or strings unless all but one of the conversion characters 306or strings is 307.Cm \&_a 308or 309.Cm \&_A . 310.Pp 311If, as a result of the specification of the 312.Fl n 313option or end-of-file being reached, input data only partially 314satisfies a format string, the input block is zero-padded sufficiently 315to display all available data (i.e. any format units overlapping the 316end of data will display some number of the zero bytes). 317.Pp 318Further output by such format strings is replaced by an equivalent 319number of spaces. 320An equivalent number of spaces is defined as the number of spaces 321output by an 322.Cm s 323conversion character with the same field width 324and precision as the original conversion character or conversion 325string but with any 326.Dq Li \&+ , 327.Dq \&\ \& , 328.Dq Li \&# 329conversion flag characters 330removed, and referencing a NULL string. 331.Pp 332If no format strings are specified, the default display is equivalent 333to specifying the 334.Fl x 335option. 336.Sh EXIT STATUS 337.Ex -std hexdump hd 338.Sh EXAMPLES 339Display the input in perusal format: 340.Bd -literal -offset indent 341"%06.6_ao " 12/1 "%3_u " 342"\et\et" "%_p " 343"\en" 344.Ed 345.Pp 346Implement the \-x option: 347.Bd -literal -offset indent 348"%07.7_Ax\en" 349"%07.7_ax " 8/2 "%04x " "\en" 350.Ed 351.Sh SEE ALSO 352.Xr gdb 1 353