OD(1)
NAME
od - dump files in octal and other formats
SYNOPSIS
od [-abcdfhiloxv] [-s[bytes]] [-w[bytes]] [-A radix] [-j
bytes] [-N bytes] [-t type] [--skip-bytes=bytes]
[--address-radix=radix] [--read-bytes=bytes] [--for-
mat=type] [--output-duplicates] [--strings[=bytes]]
[--width[=bytes]] [--traditional] [--help] [--version]
[file...]
DESCRIPTION
This documentation is no longer being maintained and may
be inaccurate or incomplete. The Texinfo documentation is
now the authoritative source.
This manual page documents the GNU version of od. od
writes to the standard output the contents of the given
files, or of the standard input if the name `-' is given.
Each line of the output consists of the offset in the
input file in the leftmost column of each line, followed
by one or more columns of data from the file, in a format
controlled by the options. By default, od prints the file
offsets in octal and the file data as two-byte octal num-
bers.
OPTIONS
-A, --address-radix=radix
Select the base in which file offsets are printed.
radix can be one of the following:
d decimal
o octal
x hexadecimal
n none (do not print offsets)
The default is octal.
-j, --skip-bytes=bytes
Skip bytes input bytes before formatting and writ-
ing. If bytes begins with `0x' or `0X', it is
interpreted in hexadecimal; otherwise, if it begins
with `0', in octal; otherwise, in decimal. Append-
ing `b' multiplies it by 512, `k' by 1024, and `m'
by 1048576.
-N, --read-bytes=bytes
Only output up to bytes bytes of each input file.
Any prefixes and suffixes on bytes are interpreted
as for the -j option.
-t, --format=type
Select the format in which to output the file data.
type is a string of one or more of the below type
indicator characters. If you include more than one
type indicator character in a single type string or
use this option more than once, od writes one copy
of each output line using each of the data types
that you specified, in the order that you speci-
fied.
a named character
c ASCII character or backslash escape
d signed decimal
f floating point
o octal
u unsigned decimal
x hexadecimal
Except for types `a' and `c', you can specify the number
of bytes to use in interpreting each number in the given
data type by following the type indicator character with a
decimal integer. Alternately, you can specify the size of
one of the C compiler's built-in data types by following
the type indicator character with one of the following
characters. For integers (d, o, u, x):
C char
S short
I int
L long
For floating point (f):
F float
D double
L long double
-v, --output-duplicates
Output consecutive lines that are identical. By
default, when two or more consecutive output lines
would be equal, od outputs only the first line, and
puts just an asterisk on the following line to
indicate that identical lines have been elided.
-s, --strings[=bytes]
Instead of the normal output, output only string
constants in the input, which are a run of at least
bytes ASCII graphic (or formatting) characters,
terminated by a NUL. If bytes is omitted, it
defaults to 3.
-w, --width[=bytes]
The number of input bytes to format per output
line. It must be a multiple of the least common
multiple of the sizes associated with the specified
output types. If bytes is omitted, it defaults to
32. If this option is not given, it defaults to
16.
--help Print a usage message and exit with a status code
indicating success.
--version
Print version information on standard output then
exit.
The next several options map the old, pre-POSIX format
specification options to the corresponding POSIX format
specs. GNU od accepts any combination of old- and new-
style options. Format specification options accumulate.
-a Output as named characters. Equivalent to -t a.
-b Output as octal bytes. Equivalent to -t oC.
-c Output as ASCII characters or backslash escapes.
Equivalent to -t c.
-d Output as unsigned decimal shorts. Equivalent to
-t u2.
-f Output as floats. Equivalent to -t fF.
-h Output as hexadecimal shorts. Equivalent to -t x2.
-i Output as decimal shorts. Equivalent to -t d2.
-l Output as decimal longs. Equivalent to -t d4.
-o Output as octal shorts. Equivalent to -t o2.
-x Output as hexadecimal shorts. Equivalent to -t x2.
--traditional
Recognize the pre-POSIX non-option arguments that
some older versions of od accepted. The following
syntax
od --traditional [file] [[+]offset[.][b]
[[+]label[.][b]]]
can be used to specify at most one file and
optional arguments specifying an offset and a
pseudo-start address, label. By default, offset is
interpreted as an octal number specifying how many
input bytes to skip before formatting and writing.
The optional trailing decimal point forces the
interpretation of offset as a decimal number. If
no decimal is specified and the offset begins with
`0x' or `0x' it is interpreted as a hexadecimal
number. If there is a trailing `b', the number of
bytes skipped will be offset multiplied by 512.
The label argument is interpreted just like offset,
but it specifies an initial pseudo-address. The
pseudo addresses are displayed in parentheses fol-
lowing any normal address.