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 July 10, 2004 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 indent 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 140Cause 141.Nm 142to display all input data. 143Without the 144.Fl v 145option, any number of groups of output lines, which would be 146identical to the immediately preceding group of output lines (except 147for the input offsets), are replaced with a line comprised of a 148single asterisk. 149.It Fl x 150.Em Two-byte hexadecimal display . 151Display the input offset in hexadecimal, followed by eight, space 152separated, four column, zero-filled, two-byte quantities of input 153data, in hexadecimal, per line. 154.El 155.Pp 156For each input file, 157.Nm 158sequentially copies the input to standard output, transforming the 159data according to the format strings specified by the 160.Fl e 161and 162.Fl f 163options, in the order that they were specified. 164.Ss Formats 165A format string contains any number of format units, separated by 166whitespace. 167A format unit contains up to three items: an iteration count, a byte 168count, and a format. 169.Pp 170The iteration count is an optional positive integer, which defaults to 171one. 172Each format is applied iteration count times. 173.Pp 174The byte count is an optional positive integer. 175If specified it defines the number of bytes to be interpreted by 176each iteration of the format. 177.Pp 178If an iteration count and/or a byte count is specified, a single slash 179must be placed after the iteration count and/or before the byte count 180to disambiguate them. 181Any whitespace before or after the slash is ignored. 182.Pp 183The format is required and must be surrounded by double quote 184(" ") marks. 185It is interpreted as a fprintf-style format string (see 186.Xr fprintf 3 ) , 187with the 188following exceptions: 189.Bl -bullet -offset indent 190.It 191An asterisk (*) may not be used as a field width or precision. 192.It 193A byte count or field precision 194.Em is 195required for each ``s'' conversion 196character (unlike the 197.Xr fprintf 3 198default which prints the entire string if the precision is unspecified). 199.It 200The conversion characters ``h'', ``l'', ``n'', ``p'' and ``q'' are 201not supported. 202.It 203The single character escape sequences 204described in the C standard are supported: 205.Bd -ragged -offset indent -compact 206.Bl -column <alert_character> 207.It "NUL \e0 208.It "<alert character> \ea 209.It "<backspace> \eb 210.It "<form-feed> \ef 211.It "<newline> \en 212.It "<carriage return> \er 213.It "<tab> \et 214.It "<vertical tab> \ev 215.El 216.Ed 217.El 218.Pp 219The 220.Nm 221utility also supports the following additional conversion strings: 222.Bl -tag -width Fl 223.It Cm \&_a Ns Op Cm dox 224Display the input offset, cumulative across input files, of the 225next byte to be displayed. 226The appended characters 227.Cm d , 228.Cm o , 229and 230.Cm x 231specify the display base 232as decimal, octal or hexadecimal respectively. 233.It Cm \&_A Ns Op Cm dox 234Identical to the 235.Cm \&_a 236conversion string except that it is only performed 237once, when all of the input data has been processed. 238.It Cm \&_c 239Output characters in the default character set. 240Nonprinting characters are displayed in three character, zero-padded 241octal, except for those representable by standard escape notation 242(see above), 243which are displayed as two character strings. 244.It Cm _p 245Output characters in the default character set. 246Nonprinting characters are displayed as a single 247.Dq Cm \&. . 248.It Cm _u 249Output US 250.Tn ASCII 251characters, 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\t001\ SOH\t002\ STX\t003\ ETX\t004\ EOT\t005\ ENQ 257.It "\&006\ ACK\t007\ BEL\t008\ BS\t009\ HT\t00A\ LF\t00B\ VT 258.It "\&00C\ FF\t00D\ CR\t00E\ SO\t00F\ SI\t010\ DLE\t011\ DC1 259.It "\&012\ DC2\t013\ DC3\t014\ DC4\t015\ NAK\t016\ SYN\t017\ ETB 260.It "\&018\ CAN\t019\ EM\t01A\ SUB\t01B\ ESC\t01C\ FS\t01D\ GS 261.It "\&01E\ RS\t01F\ US\t0FF\ 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 Xo 271.Li \&%d , \&%i , \&%o , 272.Li \&%u , \&%X , \&%x 273.Xc 274Four byte default, one, two and four byte counts supported. 275.It Xo 276.Li \&%E , \&%e , \&%f , 277.Li \&%G , \&%g 278.Xc 279Eight byte default, four and twelve byte counts supported. 280.El 281.Pp 282The amount of data interpreted by each format string is the sum of the 283data required by each format unit, which is the iteration count times the 284byte count, or the iteration count times the number of bytes required by 285the format if the byte count is not specified. 286.Pp 287The input is manipulated in ``blocks'', where a block is defined as the 288largest amount of data specified by any format string. 289Format strings interpreting less than an input block's worth of data, 290whose last format unit both interprets some number of bytes and does 291not have a specified iteration count, have the iteration count 292incremented until the entire input block has been processed or there 293is not enough data remaining in the block to satisfy the format string. 294.Pp 295If, either as a result of user specification or 296.Nm 297modifying 298the iteration count as described above, an iteration count is 299greater than one, no trailing whitespace characters are output 300during the last iteration. 301.Pp 302It is an error to specify a byte count as well as multiple conversion 303characters or strings unless all but one of the conversion characters 304or strings is 305.Cm \&_a 306or 307.Cm \&_A . 308.Pp 309If, as a result of the specification of the 310.Fl n 311option or end-of-file being reached, input data only partially 312satisfies a format string, the input block is zero-padded sufficiently 313to display all available data (i.e., any format units overlapping the 314end of data will display some number of the zero bytes). 315.Pp 316Further output by such format strings is replaced by an equivalent 317number of spaces. 318An equivalent number of spaces is defined as the number of spaces 319output by an 320.Cm s 321conversion character with the same field width 322and precision as the original conversion character or conversion 323string but with any 324.Dq Li \&+ , 325.Dq \&\ \& , 326.Dq Li \&# 327conversion flag characters 328removed, and referencing a NULL string. 329.Pp 330If no format strings are specified, the default display is equivalent 331to specifying the 332.Fl x 333option. 334.Sh EXIT STATUS 335.Ex -std hexdump hd 336.Sh EXAMPLES 337Display the input in perusal format: 338.Bd -literal -offset indent 339"%06.6_ao " 12/1 "%3_u " 340"\et\et" "%_p " 341"\en" 342.Ed 343.Pp 344Implement the \-x option: 345.Bd -literal -offset indent 346"%07.7_Ax\en" 347"%07.7_ax " 8/2 "%04x " "\en" 348.Ed 349.Sh SEE ALSO 350.Xr gdb 1 , 351.Xr od 1 352