NAME

od — octal, decimal, hex, ascii dump

SYNOPSIS

od	[-aBbcDdeFfHhIiLlOovXx] [-A base] [-j skip] [-N length] [-t type_string] [[+]offset[.][Bb]] [file ...]

DESCRIPTION

The od utility is a filter which displays each specified file, or the standard input if no file arguments are specified, in a user specified format.

The options are as follows:

-A base

Specify the input address base. base may be one of ‘d’, ‘o’, ‘x’ or ‘n’, which specify decimal, octal, hexadecimal addresses or no address, respectively.

-a

One-byte character display. Display the input offset in octal, followed by sixteen space-separated, three column, space-filled, characters of input data per line. Control characters are printed as their names instead of as C-style escapes.

-B

Same as -o.

-b

One-byte octal display. Display the input offset in octal, followed by sixteen space-separated, three column, zero-filled, bytes of input data, in octal, per line. This is the default output style if no other is selected.

-c

One-byte character display. Display the input offset in octal, followed by sixteen space-separated, three column, space-filled, characters of input data per line. Control characters are printed at C-style escapes, or as three octal digits, if no C escape exists for the character.

-d

Two-byte decimal display. Display the input offset in octal, followed by eight space-separated, five column, zero-filled, two-byte units of input data, in unsigned decimal, per line.

-e

Eight-byte floating point display. Display the input offset in octal, followed by two space-separated, twenty-one column, space filled, eight byte units of input data, in floating point, per line.

-F

Same as -e.

-f

Four-byte floating point display. Display the input offset in octal, followed by four space-separated, 14 column, space filled, four byte units of input data, in floating point, per line.

-H

Four-byte hex display. Display the input offset in octal, followed by four space-separated, eight column, zero filled, four byte units of input data, in hex, per line.

-h

Two-byte hex display. Display the input offset in octal, followed by eight space-separated, four column, zero filled, two byte units of input data, in hex, per line.

-I

Four-byte decimal display. Display the input offset in octal, followed by four space-separated, eleven column, space filled, four byte units of input data, in decimal, per line.

-i

Two-byte decimal display. Display the input offset in octal, followed by eight space-separated, six column, space filled, two-byte units of input data, in decimal, per line.

-j skip

Skip skip bytes from the beginning of the input. By default, skip is interpreted as a decimal number. With a leading 0x or 0X, skip is interpreted as a hexadecimal number; otherwise, with a leading 0, skip is interpreted as an octal number. Appending the character b, k, or m to skip causes it to be interpreted as a multiple of 512, 1024, or 1048576, respectively.

-L

Same as -I.

-l

Same as -I.

-N length

Interpret only length bytes of input.

-O

Four-byte octal display. Display the input offset in octal, followed by four space-separated, eleven column, zero-filled, four-byte units of input data, in octal, per line.

-o

Two-byte octal display. Display the input offset in octal, followed by eight space-separated, six column, zero-filled, two-byte units of input data, in octal, per line.

-t type_string

Specify one or more output types. The type_string option-argument must be a string specifying the types to be used when writing the input data. The string must consist of the type specification characters:

a selects US-ASCII output, with control characters replaced with their names instead of as C escape sequences. See also the _u conversion provided by hexdump(1).

c selects a standard character based conversion. See also the _c conversion provided by hexdump(1).

f selects the floating point output format. This type character can be optionally followed by the characters 4 or F to specify four byte floating point output, or 8 or L to specify eight byte floating point output. The default output format is eight byte floats. See also the e conversion provided by hexdump(1).

d, o, u, or x select decimal, octal, unsigned decimal, or hex output respectively. These types can optionally be followed by C to specify char-sized output, S to specify short-sized output, I to specify int-sized output, L to specify long-sized output, 1 to specify one-byte output, 2 to specify two-byte output, 4 to specify four-byte output, or 8 to specify eight-byte output. The default output format is in four-byte quantities. See also the d, o, u, and x conversions provided by hexdump(1).

-v

The -v option causes od to display all input data. Without the -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 (‘*’).

-X

Same as -H.

-x

Same as -h.

For each input file, od sequentially copies the input to standard output, transforming the data according to the options given. If no options are specified, the default display is equivalent to specifying the -o option.

EXIT STATUS

The od utility exits 0 on success, and >0 if an error occurs.

SEE ALSO

hexdump(1), strings(1)

HISTORY

An od command appeared in Version 1 AT&T UNIX.

This man page was initially written in February 2001 by Andrew Brown, shortly after he augmented the deprecated od syntax to include things he felt had been missing for a long time.