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
numbers.
-A, --address-radix=radix
Select the base in which file offsets are printed.
radix
can be one of the following:
none (do not print offsets)
The default is octal.
-j, --skip-bytes=bytes
Skip
bytes
input bytes before formatting and writing. If
bytes
begins with `0x' or `0X', it is interpreted in hexadecimal; otherwise,
if it begins with `0', in octal; otherwise, in decimal. Appending `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 specified.
ASCII character or backslash escape
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):
For floating point (f):
-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 following any normal address.