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.\" $FreeBSD$ 34.\" 35.Dd April 18, 1994 36.Dt HEXDUMP 1 37.Os 38.Sh NAME 39.Nm hexdump , hd 40.Nd ASCII, decimal, hexadecimal, octal dump 41.Sh SYNOPSIS 42.Nm 43.Op Fl bcCdovx 44.Op Fl e Ar format_string 45.Op Fl f Ar format_file 46.Op Fl n Ar length 47.Bk -words 48.Op Fl s Ar skip 49.Ek 50.Ar 51.Nm hd 52.Op Fl bcdovx 53.Op Fl e Ar format_string 54.Op Fl f Ar format_file 55.Op Fl n Ar length 56.Bk -words 57.Op Fl s Ar skip 58.Ek 59.Ar 60.Sh DESCRIPTION 61The 62.Nm 63utility is a filter which displays the specified files, or 64the standard input, if no files are specified, in a user specified 65format. 66.Pp 67The options are as follows: 68.Bl -tag -width Fl 69.It Fl b 70.Em One-byte octal display . 71Display the input offset in hexadecimal, followed by sixteen 72space-separated, three column, zero-filled, bytes of input data, 73in octal, per line. 74.It Fl c 75.Em One-byte character display . 76Display the input offset in hexadecimal, followed by sixteen 77space-separated, three column, space-filled, characters of input 78data per line. 79.It Fl C 80.Em Canonical hex+ASCII display . 81Display the input offset in hexadecimal, followed by sixteen 82space-separated, two column, hexadecimal bytes, followed by the 83same sixteen bytes in %_p format enclosed in ``|'' characters. 84.Pp 85Calling the command 86.Nm hd 87implies this option. 88.It Fl d 89.Em Two-byte decimal display . 90Display the input offset in hexadecimal, followed by eight 91space-separated, five column, zero-filled, two-byte units 92of input data, in unsigned decimal, per line. 93.It Fl e Ar format_string 94Specify a format string to be used for displaying data. 95.It Fl f Ar format_file 96Specify a file that contains one or more newline separated format strings. 97Empty lines and lines whose first non-blank character is a hash mark 98.Pf ( Cm \&# ) 99are ignored. 100.It Fl n Ar length 101Interpret only 102.Ar length 103bytes of input. 104.It Fl o 105.Em Two-byte octal display . 106Display the input offset in hexadecimal, followed by eight 107space-separated, six column, zero-filled, two byte quantities of 108input data, in octal, per line. 109.It Fl s Ar offset 110Skip 111.Ar offset 112bytes from the beginning of the input. 113By default, 114.Ar offset 115is interpreted as a decimal number. 116With a leading 117.Cm 0x 118or 119.Cm 0X , 120.Ar offset 121is interpreted as a hexadecimal number, 122otherwise, with a leading 123.Cm 0 , 124.Ar offset 125is interpreted as an octal number. 126Appending the character 127.Cm b , 128.Cm k , 129or 130.Cm m 131to 132.Ar offset 133causes it to be interpreted as a multiple of 134.Li 512 , 135.Li 1024 , 136or 137.Li 1048576 , 138respectively. 139.It Fl v 140The 141.Fl v 142option causes 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 221.Nm Hexdump 222also supports the following additional conversion strings: 223.Bl -tag -width Fl 224.It Cm \&_a Ns Op Cm dox 225Display the input offset, cumulative across input files, of the 226next byte to be displayed. 227The appended characters 228.Cm d , 229.Cm o , 230and 231.Cm x 232specify the display base 233as decimal, octal or hexadecimal respectively. 234.It Cm \&_A Ns Op Cm dox 235Identical to the 236.Cm \&_a 237conversion string except that it is only performed 238once, when all of the input data has been processed. 239.It Cm \&_c 240Output characters in the default character set. 241Nonprinting characters are displayed in three character, zero-padded 242octal, except for those representable by standard escape notation 243(see above), 244which are displayed as two character strings. 245.It Cm _p 246Output characters in the default character set. 247Nonprinting characters are displayed as a single 248.Dq Cm \&. . 249.It Cm _u 250Output US ASCII characters, with the exception that control characters are 251displayed using the following, lower-case, names. 252Characters greater than 0xff, hexadecimal, are displayed as hexadecimal 253strings. 254.Bl -column \&000_nu \&001_so \&002_st \&003_et \&004_eo 255.It "\&000\ nul\t001\ soh\t002\ stx\t003\ etx\t004\ eot\t005\ enq 256.It "\&006\ ack\t007\ bel\t008\ bs\t009\ ht\t00A\ lf\t00B\ vt 257.It "\&00C\ ff\t00D\ cr\t00E\ so\t00F\ si\t010\ dle\t011\ dc1 258.It "\&012\ dc2\t013\ dc3\t014\ dc4\t015\ nak\t016\ syn\t017\ etb 259.It "\&018\ can\t019\ em\t01A\ sub\t01B\ esc\t01C\ fs\t01D\ gs 260.It "\&01E\ rs\t01F\ us\t0FF\ del 261.El 262.El 263.Pp 264The default and supported byte counts for the conversion characters 265are as follows: 266.Bl -tag -width "Xc,_Xc,_Xc,_Xc,_Xc,_Xc" -offset indent 267.It Li \&%_c , \&%_p , \&%_u , \&%c 268One byte counts only. 269.It Xo 270.Li \&%d , \&%i , \&%o , 271.Li \&%u , \&%X , \&%x 272.Xc 273Four byte default, one, two and four byte counts supported. 274.It Xo 275.Li \&%E , \&%e , \&%f , 276.Li \&%G , \&%g 277.Xc 278Eight byte default, four byte counts supported. 279.El 280.Pp 281The amount of data interpreted by each format string is the sum of the 282data required by each format unit, which is the iteration count times the 283byte count, or the iteration count times the number of bytes required by 284the format if the byte count is not specified. 285.Pp 286The input is manipulated in ``blocks'', where a block is defined as the 287largest amount of data specified by any format string. 288Format strings interpreting less than an input block's worth of data, 289whose last format unit both interprets some number of bytes and does 290not have a specified iteration count, have the iteration count 291incremented until the entire input block has been processed or there 292is not enough data remaining in the block to satisfy the format string. 293.Pp 294If, either as a result of user specification or 295.Nm 296modifying 297the iteration count as described above, an iteration count is 298greater than one, no trailing whitespace characters are output 299during the last iteration. 300.Pp 301It is an error to specify a byte count as well as multiple conversion 302characters or strings unless all but one of the conversion characters 303or strings is 304.Cm \&_a 305or 306.Cm \&_A . 307.Pp 308If, as a result of the specification of the 309.Fl n 310option or end-of-file being reached, input data only partially 311satisfies a format string, the input block is zero-padded sufficiently 312to display all available data (i.e. any format units overlapping the 313end of data will display some number of the zero bytes). 314.Pp 315Further output by such format strings is replaced by an equivalent 316number of spaces. 317An equivalent number of spaces is defined as the number of spaces 318output by an 319.Cm s 320conversion character with the same field width 321and precision as the original conversion character or conversion 322string but with any 323.Dq Li \&+ , 324.Dq \&\ \& , 325.Dq Li \&# 326conversion flag characters 327removed, and referencing a NULL string. 328.Pp 329If no format strings are specified, the default display is equivalent 330to specifying the 331.Fl x 332option. 333.Sh DIAGNOSTICS 334.Ex -std hexdump hd 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 \-x option: 344.Bd -literal -offset indent 345"%07.7_Ax\en" 346"%07.7_ax " 8/2 "%04x " "\en" 347.Ed 348.Sh SEE ALSO 349.Xr gdb 1 350