freebsd-skq/usr.bin/hexdump/od.1
fernape a801bf2de6 od(1): Add EXAMPLES section
* Add two small examples showing the use of -a, -c, -j and -N
 * While here, remove obsolete .Tn reported by mandoc(1)

Approved by:	0mp@
Differential Revision:	https://reviews.freebsd.org/D25372
2020-06-23 07:48:48 +00:00

283 lines
6.5 KiB
Groff

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.\" @(#)od.1 8.1 (Berkeley) 6/6/93
.\" $FreeBSD$
.\"
.Dd December 22, 2011
.Dt OD 1
.Os
.Sh NAME
.Nm od
.Nd octal, decimal, hex, ASCII dump
.Sh SYNOPSIS
.Nm
.Op Fl aBbcDdeFfHhIiLlOosvXx
.Op Fl A Ar base
.Op Fl j Ar skip
.Op Fl N Ar length
.Op Fl t Ar type
.Op Oo Cm + Oc Ns Ar offset Ns Oo Cm \&. Oc Ns Op Cm Bb
.Op Ar
.Sh DESCRIPTION
The
.Nm
utility is a filter which displays the specified files, or standard
input if no files are specified, in a user specified format.
.Pp
The options are as follows:
.Bl -tag -width ".Fl I , L , l"
.It Fl A Ar base
Specify the input address base.
The argument
.Ar base
may be one of
.Cm d ,
.Cm o ,
.Cm x
or
.Cm n ,
which specify decimal, octal, hexadecimal
addresses or no address, respectively.
.It Fl a
Output named characters.
Equivalent to
.Fl t Cm a .
.It Fl B , o
Output octal shorts.
Equivalent to
.Fl t Cm o2 .
.It Fl b
Output octal bytes.
Equivalent to
.Fl t Cm o1 .
.It Fl c
Output C-style escaped characters.
Equivalent to
.Fl t Cm c .
.It Fl D
Output unsigned decimal ints.
Equivalent to
.Fl t Cm u4 .
.It Fl d
Output unsigned decimal shorts.
Equivalent to
.Fl t Cm u2 .
.It Fl e , F
Output double-precision floating point numbers.
Equivalent to
.Fl t Cm fD .
.It Fl f
Output single-precision floating point numbers.
Equivalent to
.Fl t Cm fF .
.It Fl H , X
Output hexadecimal ints.
Equivalent to
.Fl t Cm x4 .
.It Fl h , x
Output hexadecimal shorts.
Equivalent to
.Fl t Cm x2 .
.It Fl I , L , l
Output signed decimal longs.
Equivalent to
.Fl t Cm dL .
.It Fl i
Output signed decimal ints.
Equivalent to
.Fl t Cm dI .
.It Fl j Ar skip
Skip
.Ar skip
bytes of the combined input before dumping.
The number may be followed by one
of
.Cm b , k
or
.Cm m
which specify the units of the number as blocks (512 bytes), kilobytes and
megabytes, respectively.
.It Fl N Ar length
Dump at most
.Ar length
bytes of input.
.It Fl O
Output octal ints.
Equivalent to
.Fl t Cm o4 .
.It Fl s
Output signed decimal shorts.
Equivalent to
.Fl t Cm d2 .
.It Fl t Ar type
Specify the output format.
The
.Ar type
argument
is a string containing one or more of the following kinds of type specifiers:
.Bl -tag -width indent
.It Cm a
Named characters
.Pq ASCII .
Control characters are displayed using the following names:
.Bl -column "000 NUL" "001 SOH" "002 STX" "003 ETX" "004 EOT" "005 ENQ"
.It "000 NUL 001 SOH 002 STX 003 ETX 004 EOT 005 ENQ"
.It "006 ACK 007 BEL 008 BS 009 HT 00A NL 00B VT"
.It "00C FF 00D CR 00E SO 00F SI 010 DLE 011 DC1"
.It "012 DC2 013 DC3 014 DC4 015 NAK 016 SYN 017 ETB"
.It "018 CAN 019 EM 01A SUB 01B ESC 01C FS 01D GS"
.It "01E RS 01F US 020 SP 07F DEL \& \&"
.El
.It Cm c
Characters in the default character set.
Non-printing characters are
represented as 3-digit octal character codes, except the following
characters, which are represented as C escapes:
.Pp
.Bl -tag -width carriage-return -compact
.It NUL
\e0
.It alert
\ea
.It backspace
\eb
.It newline
\en
.It carriage-return
\er
.It tab
\et
.It vertical tab
\ev
.El
.Pp
Multi-byte characters are displayed in the area corresponding to the first
byte of the character.
The remaining bytes are shown as
.Ql ** .
.It Xo
.Sm off
.Op Cm d | o | u | x
.Op Cm C | S | I | L | Ar n
.Sm on
.Xc
Signed decimal
.Pq Cm d ,
octal
.Pq Cm o ,
unsigned decimal
.Pq Cm u
or
hexadecimal
.Pq Cm x .
Followed by an optional size specifier, which may be either
.Cm C
.Pq Vt char ,
.Cm S
.Pq Vt short ,
.Cm I
.Pq Vt int ,
.Cm L
.Pq Vt long ,
or a byte count as a decimal integer.
.It Xo
.Sm off
.Cm f
.Op Cm F | D | L | Ar n
.Sm on
.Xc
Floating-point number.
Followed by an optional size specifier, which may be either
.Cm F
.Pq Vt float ,
.Cm D
.Pq Vt double
or
.Cm L
.Pq Vt "long double" .
.El
.It Fl v
Write all input data, instead of replacing lines of duplicate values with a
.Ql * .
.El
.Pp
Multiple options that specify output format may be used; the output will
contain one line for each format.
.Pp
If no output format is specified,
.Fl t Cm oS
is assumed.
.Sh ENVIRONMENT
The
.Ev LANG , LC_ALL
and
.Ev LC_CTYPE
environment variables affect the execution of
.Nm
as described in
.Xr environ 7 .
.Sh EXIT STATUS
.Ex -std
.Sh EXAMPLES
Dump stdin and show the output using named characters and C-style escaped
characters:
.Bd -literal -offset indent
$ echo "FreeBSD: The power to serve" | od -a -c
0000000 F r e e B S D : sp T h e sp p o w
F r e e B S D : T h e p o w
0000020 e r sp t o sp s e r v e nl
e r t o s e r v e \en
0000034
.Ed
.Pp
Dump stdin skipping the first 13 bytes using named characters and dumping no
more than 5 bytes:
.Bd -literal -offset indent
$ echo "FreeBSD: The power to serve" | od -An -a -j 13 -N 5
p o w e r
.Ed
.Sh COMPATIBILITY
The traditional
.Fl s
option to extract string constants is not supported; consider using
.Xr strings 1
instead.
.Sh SEE ALSO
.Xr hexdump 1 ,
.Xr strings 1
.Sh STANDARDS
The
.Nm
utility conforms to
.St -p1003.1-2001 .
.Sh HISTORY
An
.Nm
command appeared in
.At v1 .