OD(1)OD(1)NAMEod - octal dump
SYNOPSIS
/usr/bin/od [-bcCDdFfOoSsvXx] [-] [file] [offset_string]
/usr/bin/od [-bcCDdFfOoSsvXx] [-A address_base] [-j skip]
[-N count] [-t type_string]... [-] [file]...
/usr/xpg4/bin/od [-bcCDdFfOoSsvXx] [file] [offset_string]
/usr/xpg4/bin/od [-bcCDdFfOoSsvXx] [-A address_base]
[-j skip] [-N count] [-t type_string]... [file]...
DESCRIPTION
The od command copies sequentially each input file to standard output
and transforms the input data according to the output types specified
by the -t or -bcCDdFfOoSsvXx options. If no output type is specified,
the default output is as if -t o2 had been specified. Multiple types
can be specified by using multiple -bcCDdFfOoSstvXx options. Output
lines are written for each type specified in the order in which the
types are specified. If no file is specified, the standard input is
used. The [offset_string] operand is mutually exclusive from the -A,
-j, -N, and -t options. For the purposes of this description, the fol‐
lowing terms are used:
word
Refers to a 16-bit unit, independent of the word
size of the machine.
long word
Refers to a 32-bit unit.
double long word
Refers to a 64-bit unit.
OPTIONS
The following options are supported:
-A address_base
Specifies the input offset base. The address_base
option-argument must be a character. The charac‐
ters d, o and x specify that the offset base will
be written in decimal, octal or hexadecimal,
respectively. The character n specifies that the
offset will not be written. Unless -A n is speci‐
fied, the output line will be preceded by the input
offset, cumulative across input files, of the next
byte to be written. In addition, the offset of the
byte following the last byte written will be dis‐
played after all the input data has been processed.
Without the -A address_base option and the [off‐
set_string] operand, the input offset base is dis‐
played in octal.
-b
Interprets bytes in octal. This is equivalent to
-t o1.
/usr/bin/od
-c
Displays single-byte characters. Certain non-graphic characters
appear as C-language escapes:
null \0
backspace \b
form-feed \f
new-line \n
return \r
tab \t
Others appear as 3-digit octal numbers. For example:
echo "hello world" | od −c
0000000 h e l l o w o r l d \n
0000014
/usr/xpg4/bin/od
-c
Interprets bytes as single-byte or multibyte charac‐
ters according to the current setting of the
LC_CTYPE locale category. Printable multibyte char‐
acters are written in the area corresponding to the
first byte of the character. The two-character
sequence ** is written in the area corresponding to
each remaining byte in the character, as an indica‐
tion that the character is continued. Non-graphic
characters appear the same as they would using the
-C option.
-C
Interprets bytes as single-byte or multibyte charac‐
ters according to the current setting of the
LC_CTYPE locale category. Printable multibyte char‐
acters are written in the area corresponding to the
first byte of the character. The two-character
sequence ** is written in the area corresponding to
each remaining byte in the character, as an indica‐
tion that the character is continued. Certain non-
graphic characters appear as C escapes:
null \0
backspace \b
form-feed \f
new-line \n
return \r
tab \t
Other non-printable characters appear as one three-
digit octal number for each byte in the character.
-d
Interprets words in unsigned decimal. This is
equivalent to -t u2.
-D
Interprets long words in unsigned decimal. This is
equivalent to -t u4.
-f
Interprets long words in floating point. This is
equivalent to -t f4.
-F
Interprets double long words in extended precision.
This is equivalent to -t f8.
-j skip
Jumps over skip bytes from the beginning of the
input. The od command will read or seek past the
first skip bytes in the concatenated input files.
If the combined input is not at least skip bytes
long, the od command will write a diagnostic message
to standard error and exit with a non-zero exit sta‐
tus.
By default, the skip option-argument is interpreted
as a decimal number. With a leading 0x or 0X, the
offset is interpreted as a hexadecimal number; oth‐
erwise, with a leading 0, the offset will be inter‐
preted as an octal number. Appending the character
b, k, or m to offset will cause it to be interpreted
as a multiple of 512, 1024 or 1048576 bytes, respec‐
tively. If the skip number is hexadecimal, any
appended b is considered to be the final hexadecimal
digit. The address is displayed starting at 0000000,
and its base is not implied by the base of the skip
option-argument.
-N count
Formats no more than count bytes of input. By
default, count is interpreted as a decimal number.
With a leading 0x or 0X, count is interpreted as a
hexadecimal number; otherwise, with a leading 0, it
is interpreted as an octal number. If count bytes of
input (after successfully skipping, if -jskip is
specified) are not available, it will not be consid‐
ered an error. The od command will format the input
that is available. The base of the address dis‐
played is not implied by the base of the count
option-argument.
-o
Interprets words in octal. This is equivalent to -t
o2.
-O
Interprets long words in unsigned octal. This is
equivalent to -t o4.
-s
Interprets words in signed decimal. This is equiva‐
lent to -t d2.
-S
Interprets long words in signed decimal. This is
equivalent to -t d4.
-t type_string
Specifies 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 char‐
acters:
a
Named character. Interprets bytes as named
characters. Only the least significant seven
bits of each byte will be used for this type
specification. Bytes with the values listed
in the following table will be written using
the corresponding names for those characters.
The following are named characters in od:
Value Name
00 nul
01 soh
02 stx
03 etx
04 eot
05 enq
06 ack
07 bel
10 bs
11 ht
12 lf
13 vt
14 ff
15 cr
16 so
17 si
20 dle
21 dc1
22 dc2
23 dc3
24 dc4
25 nak
26 syn
27 etb
30 can
31 em
32 sub
33 esc
34 fs
35 gs
36 rs
37 us
40 sp
177 del
c
Character. Interprets bytes as single-byte or
multibyte characters specified by the current
setting of the LC_CTYPE locale category.
Printable multibyte characters are written in
the area corresponding to the first byte of
the character. The two-character sequence **
is written in the area corresponding to each
remaining byte in the character, as an indica‐
tion that the character is continued. Certain
non-graphic characters appear as C escapes:
\0, \a, \b, \f, \n, \r, \t, \v. Other non-
printable characters appear as one three-digit
octal number for each byte in the character.
The type specification characters d, f, o, u, and x
can be followed by an optional unsigned decimal
integer that specifies the number of bytes to be
transformed by each instance of the output type.
f
Floating point. Can be followed by
an optional F, D, or L indicating
that the conversion should be
applied to an item of type float,
double, or long double, respec‐
tively.
d, o, u, and x
Signed decimal, octal, unsigned
decimal, and hexadecimal, respec‐
tively. Can be followed by an
optional C, S, I, or L indicating
that the conversion should be
applied to an item of type char,
short, int, or long, respectively.
Multiple types can be concatenated within the same
type_string and multiple -t options can be speci‐
fied. Output lines are written for each type speci‐
fied in the order in which the type specification
characters are specified.
-v
Shows all input data (verbose). Without the -v
option, all groups of output lines that would be
identical to the immediately preceding output line
(except for byte offsets), will be replaced with a
line containing only an asterisk (*).
-x
Interprets words in hex. This is equivalent to -t
x2.
-X
Interprets long words in hex. This is equivalent to
-t x4.
OPERANDS
/usr/bin/od
The following operands are supported for /usr/bin/od only:
−
Uses the standard input in addition to any
files specified. When this operand is not
given, the standard input is used only if no
file operands are specified.
file
A path name of a file to be read. If no file
operands are specified, the standard input
will be used. If there are no more than two
operands, none of the -A, -j, -N, or -t
options is specified, and any of the follow‐
ing are true:
1. the first character of the last
operand is a plus sign (+)
2. the first character of the second
operand is numeric
3. the first character of the second
operand is x and the second char‐
acter of the second operand is a
lower-case hexadecimal character
or digit
4. the second operand is named "x"
5. the second operand is named "."
then the corresponding operand is assumed to
be an offset operand rather than a file oper‐
and.
Without the -N count option, the display con‐
tinues until an end-of-file is reached.
[+][0] offset [.][b|B]
[+][0][offset] [.]
[+][0x|x][offset]
[+][0x|x] offset[B]
The offset_string operand specifies the byte
offset in the file where dumping is to com‐
mence. The offset is interpreted in octal
bytes by default. If offset begins with "0",
it is interpreted in octal. If offset begins
with "x" or "0x", it is interpreted in hexa‐
decimal and any appended "b" is considered to
be the final hexadecimal digit. If "." is
appended, the offset is interpreted in deci‐
mal. If "b" or "B" is appended, the offset is
interpreted in units of 512 bytes. If the
file argument is omitted, the offset argument
must be preceded by a plus sign (+). The
address is displayed starting at the given
offset. The radix of the address will be the
same as the radix of the offset, if speci‐
fied, otherwise it will be octal. Decimal
overrides octal, and it is an error to spec‐
ify both hexadecimal and decimal conversions
in the same offset operand.
/usr/xpg4/bin/od
The following operands are supported for /usr/xpg4/bin/od only:
file
Same as /usr/bin/od, except only one of
the first two conditions must be true.
[+] [0] offset [.][b|B]
+ [offset] [.]
[+][0x][offset]
[+][0x] offset[B]
+x [offset]
+xoffset [B]
Description of offset_string is the same
as for /usr/bin/od.
ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables
that affect the execution of od: LANG, LC_ALL, LC_CTYPE, LC_MESSAGES,
LC_NUMERIC, and NLSPATH.
EXIT STATUS
The following exit values are returned:
0
Successful completion.
>0
An error occurred.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
/usr/bin/od
┌───────────────┬─────────────────┐
│ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├───────────────┼─────────────────┤
│CSI │ enabled │
└───────────────┴─────────────────┘
/usr/xpg4/bin/od
┌────────────────────┬─────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼─────────────────┤
│CSI │ enabled │
├────────────────────┼─────────────────┤
│Interface Stability │ Standard │
└────────────────────┴─────────────────┘
SEE ALSOsed(1), attributes(5), environ(5), standards(5)
May 20, 2005 OD(1)
