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diff --git a/text-utils/hexdump.1 b/text-utils/hexdump.1 new file mode 100644 index 0000000..84ecaf4 --- /dev/null +++ b/text-utils/hexdump.1 @@ -0,0 +1,324 @@ +.\" Copyright (c) 1989, 1990, 1993 +.\" The Regents of the University of California. All rights reserved. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" from: @(#)hexdump.1 8.2 (Berkeley) 4/18/94 +.\" +.TH HEXDUMP "1" "September 2011" "util-linux" "User Commands" +.SH NAME +hexdump \- display file contents in ascii, decimal, hexadecimal, or octal +.SH SYNOPSIS +.B hexdump +[options] file [...] +.SH DESCRIPTION +The +.B hexdump +utility is a filter which displays the specified files, or +standard input if no files are specified, in a user-specified +format. +.SH OPTIONS +The \fIlength\fR and \fIoffset\fR arguments may be followed by the multiplicative +suffixes KiB=1024, MiB=1024*1024, and so on for GiB, TiB, PiB, EiB, ZiB and YiB +(the "iB" is optional, e.g. "K" has the same meaning as "KiB") or the suffixes +KB=1000, MB=1000*1000, and so on for GB, PB, EB, ZB and YB. +.TP +.B \-b +\fIOne-byte octal display\fR. Display the input offset in hexadecimal, +followed by sixteen space-separated, three-column, zero-filled bytes of input +data, in octal, per line. +.TP +.B \-c +\fIOne-byte character display\fR. Display the input offset in hexadecimal, +followed by sixteen space-separated, three-column, space-filled characters of +input data per line. +.TP +.B \-C +\fICanonical hex+ASCII display\fR. Display the input offset in hexadecimal, +followed by sixteen space-separated, two-column, hexadecimal bytes, followed +by the same sixteen bytes in +.B %_p +format enclosed in +.RB ' | ' +characters. +.TP +.B \-d +\fITwo-byte decimal display\fR. Display the input offset in hexadecimal, +followed by eight space-separated, five-column, zero-filled, two-byte units +of input data, in unsigned decimal, per line. +.TP +.BI \-e \ format_string +Specify a format string to be used for displaying data. +.TP +.BI \-f \ format_file +Specify a file that contains one or more newline separated format strings. +Empty lines and lines whose first non-blank character is a hash mark (\&#) +are ignored. +.TP +.BI \-n \ length +Interpret only +.I length +bytes of input. +.TP +.B \-o +\fITwo-byte octal display\fR. Display the input offset in hexadecimal, +followed by eight space-separated, six-column, zero-filled, two-byte +quantities of input data, in octal, per line. +.TP +.BI \-s \ offset +Skip +.I offset +bytes from the beginning of the input. +.TP +.B \-v +The +.B \-v +option causes +.B hexdump +to display all input data. Without the +.B \-v +option, any number of groups of output lines which would be identical to the +immediately preceding group of output lines (except for the input offsets), +are replaced with a line comprised of a single asterisk. +.TP +.B \-x +\fITwo-byte hexadecimal display\fR. Display the input offset in hexadecimal, +followed by eight space-separated, four-column, zero-filled, two-byte +quantities of input data, in hexadecimal, per line. +.PP +For each input file, +.B hexdump +sequentially copies the input to standard output, transforming the data +according to the format strings specified by the +.B \-e +and +.B \-f +options, in the order that they were specified. +.SH FORMATS +A format string contains any number of format units, separated by whitespace. +A format unit contains up to three items: an iteration count, a byte count, +and a format. +.PP +The iteration count is an optional positive integer, which defaults to one. +Each format is applied iteration count times. +.PP +The byte count is an optional positive integer. If specified it defines the +number of bytes to be interpreted by each iteration of the format. +.PP +If an iteration count and/or a byte count is specified, a single slash must +be placed after the iteration count and/or before the byte count to +disambiguate them. Any whitespace before or after the slash is ignored. +.PP +The format is required and must be surrounded by double quote (" ") marks. +It is interpreted as a fprintf-style format string (see +.BR fprintf (3), +with the following exceptions: +.TP +1. +An asterisk (*) may not be used as a field width or precision. +.TP +2. +A byte count or field precision +.I is +required for each +.B s +conversion character (unlike the +.BR fprintf (3) +default which prints the entire string if the precision is unspecified). +.TP +3. +The conversion characters +.BR h , \ l , \ n , \ p , +.RB and \ q +are not supported. +.TP +4. +The single character escape sequences described in the C standard are +supported: +.PP +.RS 13 +.PD 0 +.TP 21 +NULL +\e0 +.TP +<alert character> +\ea +.TP +<backspace> +\eb +.TP +<form-feed> +\ef +.TP +<newline> +\en +.TP +<carriage return> +\er +.TP +<tab> +\et +.TP +<vertical tab> +\ev +.PD +.RE +.PP +.SS Conversion strings +The +.B hexdump +utility also supports the following additional conversion strings. +.TP +.B \&_a[dox] +Display the input offset, cumulative across input files, of the next byte to +be displayed. The appended characters +.BR d , +.BR o , +and +.B x +specify the display base as decimal, octal or hexadecimal respectively. +.TP +.B \&_A[dox] +Identical to the +.B \&_a +conversion string except that it is only performed once, when all of the +input data has been processed. +.TP +.B \&_c +Output characters in the default character set. Nonprinting characters are +displayed in three-character, zero-padded octal, except for those +representable by standard escape notation (see above), which are displayed as +two-character strings. +.TP +.B \&_p +Output characters in the default character set. Nonprinting characters are +displayed as a single +.RB ' \&. '. +.TP +.B \&_u +Output US ASCII characters, with the exception that control characters are +displayed using the following, lower-case, names. Characters greater than +0xff, hexadecimal, are displayed as hexadecimal strings. +.PP +.nf + 000 nul 001 soh 002 stx 003 etx 004 eot 005 enq + 006 ack 007 bel 008 bs 009 ht 00A lf 00B vt + 00C ff 00D cr 00E so 00F si 010 dle 011 dc1 + 012 dc2 013 dc3 014 dc4 015 nak 016 syn 017 etb + 018 can 019 em 01A sub 01B esc 01C fs 01D gs + 01E rs 01F us 0FF del +.nf +.SS Counters +The default and supported byte counts for the conversion characters +are as follows: +.TP +.BR \&%_c , \ \&%_p , \ \&%_u , \ \&%c +One byte counts only. +.TP +.BR \&%d , \ \&%i , \ \&%o , \ \&%u , \ \&%X , \ \&%x +Four byte default, one, two and four byte counts supported. +.TP +.BR \&%E , \ \&%e , \ \&%f , \ \&%G , \ \&%g +Eight byte default, four byte counts supported. +.PP +The amount of data interpreted by each format string is the sum of the data +required by each format unit, which is the iteration count times the byte +count, or the iteration count times the number of bytes required by the +format if the byte count is not specified. +.PP +The input is manipulated in +.IR blocks , +where a block is defined as the largest amount of data specified by any +format string. Format strings interpreting less than an input block's worth +of data, whose last format unit both interprets some number of bytes and does +not have a specified iteration count, have the iteration count incremented +until the entire input block has been processed or there is not enough data +remaining in the block to satisfy the format string. +.PP +If, either as a result of user specification or +.B hexdump +modifying the iteration count as described above, an iteration count is +greater than one, no trailing whitespace characters are output during the +last iteration. +.PP +It is an error to specify a byte count as well as multiple conversion +characters or strings unless all but one of the conversion characters or +strings is +.B \&_a +or +.BR \&_A . +.PP +If, as a result of the specification of the +.B \-n +option or end-of-file being reached, input data only partially satisfies a +format string, the input block is zero-padded sufficiently to display all +available data (i.e. any format units overlapping the end of data will +display some number of the zero bytes). +.PP +Further output by such format strings is replaced by an equivalent number of +spaces. An equivalent number of spaces is defined as the number of spaces +output by an +.B s +conversion character with the same field width and precision as the original +conversion character or conversion string but with any +.RB ' \&+ ', +\' \', +.RB ' \&# ' +conversion flag characters removed, and referencing a NULL string. +.PP +If no format strings are specified, the default display is equivalent +to specifying the +.B \-x +option. +.SH "EXIT STATUS" +.B hexdump +exits 0 on success and >0 if an error occurred. +.SH EXAMPLES +Display the input in perusal format: +.nf + "%06.6_ao " 12/1 "%3_u " + "\et\et" "%_p " + "\en" +.nf +.PP +Implement the \-x option: +.nf + "%07.7_Ax\en" + "%07.7_ax " 8/2 "%04x " "\en" +.nf +.SH STANDARDS +The +.B hexdump +utility is expected to be IEEE Std 1003.2 ("POSIX.2") compatible. +.SH AVAILABILITY +The hexdump command is part of the util-linux package and is available from +.UR ftp://\:ftp.kernel.org\:/pub\:/linux\:/utils\:/util-linux/ +Linux Kernel Archive +.UE . |