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OD(1) General Commands Manual OD(1)

od — octal, decimal, hex, ascii dump

od [-aBbcDdeFfHhIiLlOosvXx] [-A base] [-j offset] [-N length] [-t type_string] [file ...]

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

The options are as follows:

base
Specify the input address base. The argument base may be one of d, o, x, or n, which specify decimal, octal, hexadecimal addresses or no address, respectively.
. 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.
Same as -o.
. 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.
. 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 c style escapes, or as three octal digits, if no c escape exists for the character.
. Display the input offset in octal, followed by four space-separated, ten column, space filled, four-byte units of input data, in octal, per line.
. 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.
. 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.
Same as -e.
. 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.
. 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.
. 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.
. 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.
. 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.
offset
Skip offset bytes from the beginning of the input. By default, offset is interpreted as a decimal number. With a leading 0x or 0X, offset is interpreted as a hexadecimal number, otherwise, with a leading 0, offset is interpreted as an octal number. Appending the character b, k, or m to offset causes it to be interpreted as a multiple of 512, 1024, or 1048576, respectively.

As an alternative to od -j offset [file], the X/Open System Interfaces syntax od [file] [+]offset[.][Bb] is also supported.

Same as -I.
Same as -I.
length
Interpret only length bytes of input.
. 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.
. 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.
. Display the input offset in octal, followed by eight space-separated, five column, zero-filled, two-byte units of input data, in signed decimal, per line.
type_string
Specify one or more output types. The 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 -sized output, S to specify -sized output, I to specify -sized output, L to specify -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).

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.
Same as -H.
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.

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

hexdump(1)

The od utility is compliant with the IEEE Std 1003.1-2008 (“POSIX.1”) specification.

The flags [-bcdosx] as well as the offset specifier are marked by IEEE Std 1003.1-2008 (“POSIX.1”) as being an X/Open System Interfaces option.

The flags [-aBDeFfHhIiLlOX] are extensions to that specification.

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

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

September 3, 2022 OpenBSD-current