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1 perry 1 ----
2 __NAME__
3
4
5 hexdump, hd - ASCII, decimal, hexadecimal, octal
6 dump
7 __SYNOPSIS__
8
9
10 hexdump [[-bcCdovx] [[-e format_string] [[-f format_file] [[-n
11 length] [[-s skip] file ...
12
13
14 hd [[-bcdovx] [[-e format_string] [[-f format_file] [[-n length]
15 [[-s skip] file ...
16 __DESCRIPTION__
17
18
19 The hexdump utility is a filter which displays the specified
20 files, or the standard input, if no files are specified, in
21 a user specified format.
22
23
24 The options are as follows:
25 -b '' One-byte octal display''. Display the input offsetin hexadecimal, followed by sixteen space-sepa-rated, three column, zero-filled, bytes of inputdata, in octal, per line.
26
27
28 -c''One-byte character display''. Display the inputoffset in hexadecimal, followed by sixteenspace-separated, three column, space-filled,characters of input data per line.-C''Canonical hex+ASCII display''. Display the inputoffset in hexadecimal, followed by sixteenspace-separated, two column, hexadecimal bytes,followed by the same sixteen bytes in %_p formatenclosed in ``|'' characters.Calling the command hd implies this option.-d''Two-byte decimal display''. Display the input off-set in hexadecimal, followed by eight space-sepa-rated, five column, zero-filled, two-byte unitsof input data, in unsigned decimal, per line.-e format_stringSpecify a format string to be used for displayingdata.-f format_fileSpecify a file that contains one or more newlineseparated format strings. Empty lines and lineswhose first non-blank character is a hash mark(#) are ignored.-n lengthInterpret only length bytes of input.-o''Two-byte octal display''. Display the input offsetin hexadecimal, followed by eight space-sepa-rated, six column, zero-filled, two byte quanti-ties of input data, in octal, per line.-s offsetSkip offset bytes from the beginning of theinput. By default, offset is interpreted as adecimal number. With a leading 0x or 0X, offsetis interpreted as a hexadecimal number, other-wise, with a leading 0, offset is interpreted asan octal number. Appending the character b, k,or m to offset causes it to be interpreted as amultiple of 512, 1024, or 1048576, respectively.
29
30
31 -v
32 The -v option causes hexdump to display all input data.
33 Without the -v option, any number of groups of output lines,
34 which would be identical to the immediately preceding group
35 of output lines (except for the input offsets), are replaced
36 with a line comprised of a single aster- isk.
37
38
39 -x''
40 Two-byte hexadecimal display''. Display the input offset
41 in hexadecimal, followed by eight, space separated, four
42 column, zero-filled, two-byte quantities of input data, in
43 hexadecimal, per line.
44
45
46 For each input file, hexdump sequentially copies the input
47 to standard output, transforming the data according to the
48 format strings specified by the -e and -f options, in the
49 order that they were specified.
50
51
52 __Formats__
53 A format string contains any number of format units, sepa-
54 rated by whitespace. A format unit contains up to three
55 items: an iteration count, a byte count, and a
56 format.
57
58
59 The iteration count is an optional positive integer, which
60 defaults to one. Each format is applied iteration count
61 times.
62
63
64 The byte count is an optional positive integer. If speci-
65 fied it defines the number of bytes to be interpreted by
66 each iteration of the format.
67
68
69 If an iteration count and/or a byte count is specified, a
70 single slash must be placed after the iteration count and/or
71 before the byte count to disambiguate them. Any whitespace
72 before or after the slash is ignored.
73
74
75 The format is required and must be surrounded by double
76 quote (
77 fprintf(3)), with
78 the following excep- tions:
79
80
81 An asterisk () may not be used as a field width or
82 precision.
83
84
85 A byte count or field precision ''is'' required for each
86 ``s'' conversion character (unlike the fprintf(3)
87 default which prints the entire string if the precision is
88 unspecified).
89
90
91 The conversion characters ``h'', ``l'', ``n'', ``p'' and
92 ``q'' are not supported.
93
94
95 The single character escape sequences described in the C
96 standard are supported:
97
98
99 NUL 0
100
101
102 Hexdump also supports the following additional conversion
103 strings:
104 _a[[dox] Display the input offset, cumulative across inputfiles, of the next byte to be displayed. Theappended characters d, o, and x specify the dis-play base as decimal, octal or hexadecimalrespectively.
105
106
107 _A[[dox]Identical to the _a conversion string except thatit is only performed once, when all of the inputdata has been processed._cOutput characters in the default character set.Nonprinting characters are displayed in threecharacter, zero-padded octal, except for thoserepresentable by standard escape notation (seeabove), which are displayed as two characterstrings._pOutput characters in the default character set.Nonprinting characters are displayed as a single``.''._uOutput US ASCII characters, with the exceptionthat control characters are displayed using thefollowing, lower-case, names. Characters greaterthan 0xff, hexadecimal, are displayed as hexadec-imal strings.000 nul 001 soh 002 stx 003 etx 004 eot 005 enq
108 006 ack 007 bel 008 bs 009 ht 00A lf 00B vt
109 00C ff 00D cr 00E so 00F si 010 dle 011 dc1
110 012 dc2 013 dc3 014 dc4 015 nak 016 syn 017 etb
111 018 can 019 em 01A sub 01B esc 01C fs 01D gs
112 01E rs 01F us 0FF del
113
114
115 The default and supported byte counts for the conversion
116 characters are as follows:
117 %_c
118 , %_p, %_u, %c One byte
119 counts only.
120
121
122 %d, %i, %o,
123 %u, %X, %x
124 Four byte default, one, two and four byte counts supported.
125
126
127 %E, %e, %f,
128 %G, %g
129 Eight byte default, four byte counts supported.
130
131
132 The amount of data interpreted by each format string is the
133 sum of the data required by each format unit, which is the
134 iteration count times the byte count, or the iteration count
135 times the number of bytes required by the format if the byte
136 count is not specified.
137
138
139 The input is manipulated in ``blocks'', where a block is
140 defined as the largest amount of data specified by any for-
141 mat string. Format strings interpreting less than an input
142 block's worth of data, whose last format unit both inter-
143 prets some number of bytes and does not have a specified
144 iteration count, have the iteration count incremented until
145 the entire input block has been processed or there is not
146 enough data remaining in the block to satisfy the format
147 string.
148
149
150 If, either as a result of user specification or hexdump mod-
151 ifying the iteration count as described above, an iteration
152 count is greater than one, no trailing whitespace characters
153 are output during the last iteration.
154
155
156 It is an error to specify a byte count as well as multiple
157 conversion characters or strings unless all but one of the
158 conversion characters or strings is _a or _A.
159
160
161 If, as a result of the specification of the -n option or
162 end-of-file being reached, input data only partially satis-
163 fies a format string, the input block is zero-padded suffi-
164 ciently to display all available data (i.e. any format units
165 overlapping the end of data will display some number of the
166 zero bytes).
167
168
169 Further output by such format strings is replaced by an
170 equivalent number of spaces. An equivalent number of spaces
171 is defined as the number of spaces output by an s conversion
172 character with the same field width and precision as the
173 original conversion character or conversion string but with
174 any ``+'', `` '', ``#'' conversion flag
175 characters removed, and referencing a NULL
176 string.
177
178
179 If no format strings are specified, the default display is
180 equivalent to specifying the -x option.
181
182
183 __DIAGNOSTICS__
184 __EXAMPLES__
185
186
187 Display the input in perusal format:
188
189
190 Implement the -x option:
191
192
193 __SEE ALSO__
194
195
196 gdb(1)
197
198
199 BSD April 18, 1994 1
200 ----
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