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: src/usr.bin/hexdump/hexdump.1,v 1.9.2.9 2003/02/25 20:05:17 trhodes Exp $ 30.\" 31.Dd April 18, 1994 32.Dt HEXDUMP 1 33.Os 34.Sh NAME 35.Nm hexdump , 36.Nm hd 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.Bk -words 45.Op Fl s Ar skip 46.Ek 47.Ar 48.Nm hd 49.Op Fl bcdovx 50.Op Fl e Ar format_string 51.Op Fl f Ar format_file 52.Op Fl n Ar length 53.Bk -words 54.Op Fl s Ar skip 55.Ek 56.Ar 57.Sh DESCRIPTION 58The 59.Nm 60utility is a filter which displays the specified files, or 61the standard input, if no files are specified, in a user specified 62format. 63.Pp 64The options are as follows: 65.Bl -tag -width indent 66.It Fl b 67.Em One-byte octal display . 68Display the input offset in hexadecimal, followed by sixteen 69space-separated, three column, zero-filled, bytes of input data, 70in octal, per line. 71.It Fl c 72.Em One-byte character display . 73Display the input offset in hexadecimal, followed by sixteen 74space-separated, three column, space-filled, characters of input 75data per line. 76.It Fl C 77.Em Canonical hex+ASCII display . 78Display the input offset in hexadecimal, followed by sixteen 79space-separated, two column, hexadecimal bytes, followed by the 80same sixteen bytes in %_p format enclosed in ``|'' characters. 81.Pp 82Calling the command 83.Nm hd 84implies this option. 85.It Fl d 86.Em Two-byte decimal display . 87Display the input offset in hexadecimal, followed by eight 88space-separated, five column, zero-filled, two-byte units 89of input data, in unsigned decimal, per line. 90.It Fl e Ar format_string 91Specify a format string to be used for displaying data. 92.It Fl f Ar format_file 93Specify a file that contains one or more newline separated format strings. 94Empty lines and lines whose first non-blank character is a hash mark 95.Pf ( Cm \&# ) 96are ignored. 97.It Fl n Ar length 98Interpret only 99.Ar length 100bytes of input. 101.It Fl o 102.Em Two-byte octal display . 103Display the input offset in hexadecimal, followed by eight 104space-separated, six column, zero-filled, two byte quantities of 105input data, in octal, per line. 106.It Fl s Ar offset 107Skip 108.Ar offset 109bytes from the beginning of the input. 110By default, 111.Ar offset 112is interpreted as a decimal number. 113With a leading 114.Cm 0x 115or 116.Cm 0X , 117.Ar offset 118is interpreted as a hexadecimal number, 119otherwise, with a leading 120.Cm 0 , 121.Ar offset 122is interpreted as an octal number. 123Appending the character 124.Cm b , 125.Cm k , 126or 127.Cm m 128to 129.Ar offset 130causes it to be interpreted as a multiple of 131.Li 512 , 132.Li 1024 , 133or 134.Li 1048576 , 135respectively. 136.It Fl v 137Cause 138.Nm 139to display all input data. 140Without the 141.Fl v 142option, any number of groups of output lines, which would be 143identical to the immediately preceding group of output lines (except 144for the input offsets), are replaced with a line comprised of a 145single asterisk. 146.It Fl x 147.Em Two-byte hexadecimal display . 148Display the input offset in hexadecimal, followed by eight, space 149separated, four column, zero-filled, two-byte quantities of input 150data, in hexadecimal, per line. 151.El 152.Pp 153For each input file, 154.Nm 155sequentially copies the input to standard output, transforming the 156data according to the format strings specified by the 157.Fl e 158and 159.Fl f 160options, in the order that they were specified. 161.Ss Formats 162A format string contains any number of format units, separated by 163whitespace. 164A format unit contains up to three items: an iteration count, a byte 165count, and a format. 166.Pp 167The iteration count is an optional positive integer, which defaults to 168one. 169Each format is applied iteration count times. 170.Pp 171The byte count is an optional positive integer. 172If specified it defines the number of bytes to be interpreted by 173each iteration of the format. 174.Pp 175If an iteration count and/or a byte count is specified, a single slash 176must be placed after the iteration count and/or before the byte count 177to disambiguate them. 178Any whitespace before or after the slash is ignored. 179.Pp 180The format is required and must be surrounded by double quote 181(" ") marks. 182It is interpreted as a fprintf-style format string (see 183.Xr fprintf 3 ) , 184with the 185following exceptions: 186.Bl -bullet -offset indent 187.It 188An asterisk (*) may not be used as a field width or precision. 189.It 190A byte count or field precision 191.Em is 192required for each ``s'' conversion 193character (unlike the 194.Xr fprintf 3 195default which prints the entire string if the precision is unspecified). 196.It 197The conversion characters ``h'', ``l'', ``n'', ``p'' and ``q'' are 198not supported. 199.It 200The single character escape sequences 201described in the C standard are supported: 202.Bd -ragged -offset indent -compact 203.Bl -column <alert_character> 204.It "NUL" Ta "\e0" 205.It "<alert character>" Ta "\ea" 206.It "<backspace>" Ta "\eb" 207.It "<form-feed>" Ta "\ef" 208.It "<newline>" Ta "\en" 209.It "<carriage return>" Ta "\er" 210.It "<tab>" Ta "\et" 211.It "<vertical tab>" Ta "\ev" 212.El 213.Ed 214.El 215.Pp 216The 217.Nm 218utility also supports the following additional conversion strings: 219.Bl -tag -width Fl 220.It Cm \&_a Ns Op Cm dox 221Display the input offset, cumulative across input files, of the 222next byte to be displayed. 223The appended characters 224.Cm d , 225.Cm o , 226and 227.Cm x 228specify the display base 229as decimal, octal or hexadecimal respectively. 230.It Cm \&_A Ns Op Cm dox 231Identical to the 232.Cm \&_a 233conversion string except that it is only performed 234once, when all of the input data has been processed. 235.It Cm \&_c 236Output characters in the default character set. 237Nonprinting characters are displayed in three character, zero-padded 238octal, except for those representable by standard escape notation 239(see above), 240which are displayed as two character strings. 241.It Cm _p 242Output characters in the default character set. 243Nonprinting characters are displayed as a single 244.Dq Cm \&. . 245.It Cm _u 246Output US 247.Tn ASCII 248characters, with the exception that control characters are 249displayed using the following, lower-case, names. 250Characters greater than 0xFF, hexadecimal, are displayed as hexadecimal 251strings. 252.Bl -column "000 nulx" "001 sohx" "002 stxx" "003 etxx" "004 eotx" "005 enqx" 253.It "000 nul" Ta "001 soh" Ta "002 stx" Ta "003 etx" Ta "004 eot" Ta "005 enq" 254.It "006 ack" Ta "007 bel" Ta "008 bs" Ta "009 ht" Ta "00A nl" Ta "00B vt" 255.It "00C ff" Ta "00D cr" Ta "00E so" Ta "00F si" Ta "010 dle" Ta "011 dc1" 256.It "012 dc2" Ta "013 dc3" Ta "014 dc4" Ta "015 nak" Ta "016 syn" Ta "017 etb" 257.It "018 can" Ta "019 em" Ta "01a sub" Ta "01B esc" Ta "01C fs" Ta "01D gs" 258.It "01E rs" Ta "01F us" Ta "0FF del" Ta "" Ta "" Ta "" 259.El 260.El 261.Pp 262The default and supported byte counts for the conversion characters 263are as follows: 264.Bl -tag -width "Xc,_Xc,_Xc,_Xc,_Xc,_Xc" -offset indent 265.It Li \&%_c , \&%_p , \&%_u , \&%c 266One byte counts only. 267.It Xo 268.Li \&%d , \&%i , \&%o , 269.Li \&%u , \&%X , \&%x 270.Xc 271Four byte default, one, two and four byte counts supported. 272.It Xo 273.Li \&%E , \&%e , \&%f , 274.Li \&%G , \&%g 275.Xc 276Eight byte default, four and twelve byte counts supported. 277.El 278.Pp 279The amount of data interpreted by each format string is the sum of the 280data required by each format unit, which is the iteration count times the 281byte count, or the iteration count times the number of bytes required by 282the format if the byte count is not specified. 283.Pp 284The input is manipulated in ``blocks'', where a block is defined as the 285largest amount of data specified by any format string. 286Format strings interpreting less than an input block's worth of data, 287whose last format unit both interprets some number of bytes and does 288not have a specified iteration count, have the iteration count 289incremented until the entire input block has been processed or there 290is not enough data remaining in the block to satisfy the format string. 291.Pp 292If, either as a result of user specification or 293.Nm 294modifying 295the iteration count as described above, an iteration count is 296greater than one, no trailing whitespace characters are output 297during the last iteration. 298.Pp 299It is an error to specify a byte count as well as multiple conversion 300characters or strings unless all but one of the conversion characters 301or strings is 302.Cm \&_a 303or 304.Cm \&_A . 305.Pp 306If, as a result of the specification of the 307.Fl n 308option or end-of-file being reached, input data only partially 309satisfies a format string, the input block is zero-padded sufficiently 310to display all available data (i.e. any format units overlapping the 311end of data will display some number of the zero bytes). 312.Pp 313Further output by such format strings is replaced by an equivalent 314number of spaces. 315An equivalent number of spaces is defined as the number of spaces 316output by an 317.Cm s 318conversion character with the same field width 319and precision as the original conversion character or conversion 320string but with any 321.Dq Li \&+ , 322.Dq \&\ \& , 323.Dq Li \&# 324conversion flag characters 325removed, and referencing a NULL string. 326.Pp 327If no format strings are specified, the default display is equivalent 328to specifying the 329.Fl x 330option. 331.Sh EXIT STATUS 332.Ex -std hexdump hd 333.Sh EXAMPLES 334Display the input in perusal format: 335.Bd -literal -offset indent 336"%06.6_ao " 12/1 "%3_u " 337"\et\et" "%_p " 338"\en" 339.Ed 340.Pp 341Implement the \-x option: 342.Bd -literal -offset indent 343"%07.7_Ax\en" 344"%07.7_ax " 8/2 "%04x " "\en" 345.Ed 346.Sh SEE ALSO 347.Xr gdb 1 348