OD(1) General Commands Manual OD(1)

od — octal, decimal, hex, ASCII dump

od [-aBbcDdeFfHhIiLlOosvXx] [-A base] [-j skip] [-N length] [-t type] [[+]offset[.][Bb]] [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.
Output named characters. Equivalent to -t a.
, -o
Output octal shorts. Equivalent to -t o2.
Output octal bytes. Equivalent to -t o1.
Output C-style escaped characters. Equivalent to -t c.
Output unsigned decimal ints. Equivalent to -t u4.
Output unsigned decimal shorts. Equivalent to -t u2.
, -F
Output double-precision floating point numbers. Equivalent to -t fD.
Output single-precision floating point numbers. Equivalent to -t fF.
, -X
Output hexadecimal ints. Equivalent to -t x4.
, -x
Output hexadecimal shorts. Equivalent to -t x2.
, -L, -l
Output signed decimal longs. Equivalent to -t dL.
Output signed decimal ints. Equivalent to -t dI.
skip
Skip skip bytes of the combined input before dumping. The number may be followed by one of b, k, m or g which specify the units of the number as blocks (512 bytes), kilobytes, megabytes and gigabytes, respectively.
length
Dump at most length bytes of input.
Output octal ints. Equivalent to -t o4.
Output signed decimal shorts. Equivalent to -t d2.
type
Specify the output format. The type argument is a string containing one or more of the following kinds of type specifiers:
Named characters (ASCII). Control characters are displayed using the following names:
000 NUL 001 SOH 002 STX 003 ETX 004 EOT 005 ENQ
006 ACK 007 BEL 008 BS 009 HT 00A NL 00B VT
00C FF 00D CR 00E SO 00F SI 010 DLE 011 DC1
012 DC2 013 DC3 014 DC4 015 NAK 016 SYN 017 ETB
018 CAN 019 EM 01A SUB 01B ESC 01C FS 01D GS
01E RS 01F US 020 SP 07F DEL
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:

NUL
\0
alert
\a
backspace
\b
newline
\n
carriage-return
\r
tab
\t
vertical tab
\v

Multi-byte characters are displayed in the area corresponding to the first byte of the character. The remaining bytes are shown as ‘**’.

[d|o|u|x][C|S|I|L|n]
Signed decimal (d), octal (o), unsigned decimal (u) or hexadecimal (x). Followed by an optional size specifier, which may be either C (char), S (short), I (int), L (long), or a byte count as a decimal integer.
f[F|D|L|n]
Floating-point number. Followed by an optional size specifier, which may be either F (float), D (double) or L (long double).
Write all input data, instead of replacing lines of duplicate values with a ‘*’.

Multiple options that specify output format may be used; the output will contain one line for each format.

If no output format is specified, -t oS is assumed.

The LANG, LC_ALL and LC_CTYPE environment variables affect the execution of od as described in environ(7).

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

Dump stdin and show the output using named characters and C-style escaped characters:

$ 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  \n
0000034

Dump stdin skipping the first 13 bytes using named characters and dumping no more than 5 bytes:

$ echo "FreeBSD: The power to serve" | od -An -a -j 13 -N 5
           p   o   w   e   r

The traditional -s option to extract string constants is not supported; consider using strings(1) instead.

hexdump(1), strings(1)

The od utility conforms to IEEE Std 1003.1-2001 (“POSIX.1”).

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

December 22, 2011 macOS 15.0