od - Writes the contents of a file to standard output
od [-v] [-Q] [-A address_base] [-j skip] [-N count] [-t
type_string...] [file...]
od [-abBcCdDefFhHiIlLoOpPSvxX] [-s[number]] [-w[number]]
[file...] [+] [offset] [.] [b | B] [label] [.] [b | B]
The od command reads file (standard input by default), and
writes the information stored in file to standard output
using the format specified by the first option. If you do
not specify the first option, the -o option is the
default.
Interfaces documented on this reference page conform to
industry standards as follows:
od: XCU5.0
Refer to the standards(5) reference page for more information
about industry standards and associated tags.
Format characters are as follows: [Tru64 UNIX] Displays
quadwords as hexadecimal values. This option applies only
to the operating system for Alpha AXP systems. [Tru64
UNIX] Displays bytes as characters and displays them with
their ASCII names. If the p character is also given,
bytes with even parity are underlined. The P character
causes bytes with odd parity to be underlined. Otherwise,
parity is ignored. Specifies the input offset base with
the single-character address_base argument. The characters
d, o, and x specify that the offset base be written
in decimal, octal, or hexadecimal, respectively. The
character n specifies that the offset not be written at
all. Displays bytes as octal values. [Tru64 UNIX] Displays
short words as octal values. Displays bytes as
characters using the current setting of the LC_CTYPE variable.
The following nongraphic characters appear as C
escape sequences: Null [Tru64 UNIX] Alarm (or bell)
Backspace Formfeed Newline character Enter Tab [Tru64
UNIX] Vertical tab
Other nongraphic characters appear as 3-digit octal
numbers. Bytes with the parity bit set are displayed
in octal. [Tru64 UNIX] Displays any
extended characters as standard printable ASCII
characters using the appropriate character escape
string. Displays short words as unsigned decimal
values. [Tru64 UNIX] Displays long words as
unsigned decimal values. [Tru64 UNIX] Displays
long words as double-precision, floating-point.
(Same as -F.) [Tru64 UNIX] Displays long words as
single-precision, floating-point. [Tru64
UNIX] Displays long words as double-precision,
floating-point. [Tru64 UNIX] Displays short words
as unsigned hexadecimal values. [Tru64 UNIX] Displays
long words as unsigned hexadecimal values.
[Tru64 UNIX] Displays short words as signed
decimal values. [Tru64 UNIX] Display long words
as signed decimal values. (The three options are
identical.) Jumps over (reading or seeking) skip
bytes from the beginning of the concatenated input
files. If the input is not at least skip bytes
long, od writes a diagnostic message to standard
error and returns a nonzero exit value.
The skip argument is interpreted as a decimal number
by default. If you include a leading offset of
0x or 0X, skip is interpreted as a hexadecimal number.
A leading offset of 0 (zero) causes skip to
be interpreted as an octal number.
If you append the character b, k, or m to skip, the
number is interpreted as a multiple of 512, 1024,
or 1,048,576 bytes, respectively. If b is appended
to a skip interpreted as hexadecimal, it is recognized
as the last digit of the skip, not a block
indicator. Causes od to format no more than count
bytes of input.
The count argument is interpreted as a decimal number
by default. If you include a leading offset of
0x or 0X, count is interpreted as a hexadecimal
number. A leading offset of 0 (zero) causes count
to be interpreted as an octal number. If there are
not count bytes of input available (after successfully
skipping bytes as specified by -j), od formats
the available input. Displays short words as
octal values. [Tru64 UNIX] Displays long words as
unsigned octal values. [Tru64 UNIX] Indicates
even parity on -a conversion. [Tru64 UNIX] Indicates
odd parity on -a conversion. [Tru64
UNIX] Looks for strings of ASCII graphic characters,
terminated with a null byte. The number
argument specifies the minimum length string to be
recognized. By default, the minimum length is 3
characters. Allowable characters are those between
blank (040) and tilde (0176), as well as backspace,
tab, linefeed, formfeed, and carriage-return (010
through 015, except 013). If the environment variable
CMD_ENV is set to svr4, displays signed words
(32-bit or Tru64 UNIX short words) as signed decimal
values.
[Tru64 UNIX] If the environment variable CMD_ENV
is set to xpg4, action is the same as using the -i
option. [Tru64 UNIX] Displays long words as
signed decimal values. Specifies one or more output
types. The type_string argument is a string
that specifies the types to be used when writing
the input data. The type_string argument consists
of the following type specification characters:
Named character Character Signed decimal Floating
point Octal Unsigned decimal Hexadecimal
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.
The type specification character f can be followed
by one of the following optional characters, which
indicate the type of the item to which the conversion
should be applied. float double long double
The type specification characters d, o, u, and x
can be followed by one of the following optional
characters, which indicate the type of the item to
which the conversion should be applied: char int
long short
You can concatenate multiple types within the same
type_string argument and you can specify multiple
-t arguments. The od command writes the output
lines for each type specified in the order in which
you entered the type specification characters.
Shows all data. By default, display lines that are
identical to the previous line are not output
(except for the byte offsets), but are indicated
with an * (asterisk) in column 1. [Tru64
UNIX] Specifies the number of input bytes to be
interpreted and displayed on each output line. If
-w is not specified, 16 bytes are read for each
display line. If number is not specified, it
defaults to 32. Displays short words as unsigned
hexadecimal values. (Same as -h.) [Tru64
UNIX] Displays long words as unsigned hexadecimal
values. (Same as -H.)
[Tru64 UNIX] An uppercase format character implies the
long or double-precision form of the object.
A path name of a file to be written. If no file operands
are specified, the standard input will be used. If the
first character of file is a plus sign (+) or the first
character of the first file operand is numeric, no more
than two operands are given, and none of the -A, -j, -N,
or -t options is specified, the operand is assumed to be
an offset. Specifies the point in the file at which the
output starts. The offset argument is interpreted as
octal bytes. If a . (dot) is added to offset, it is
interpreted in decimal. If offset begins with x or 0x, it
is interpreted in hexadecimal. If b (B) is appended to a
nonhexadecimal offset, the offset is interpreted as a
block count, where a block is 512 (1024) bytes. If b (B)
is appended to a hexadecimal offset, the b (B) is interpreted
as part of the offset and the offset is not interpreted
as a block count; a block count can be specified
only with a decimal or an octal offset. Interpreted as a
pseudoaddress for the first byte displayed. It is shown
in parentheses following the file offset. It is intended
to be used with core images to indicate the real memory
address. The syntax for label is identical to that for
offset.
The output continues until the end of the file.
When od reads standard input, the offset and label
operands must be preceded by a + (plus sign).
If you omit the file argument and do not specify -A, -j,
-N, or -t, you must precede the offset argument by a +
(plus sign) character.
To be sure that od assumes the argument to be an offset:
Make the first character of file a + sign, or the first
character of the first file argument numeric. Give no
more than two arguments. Specify none of the -A, -j, -N,
or -t options.
The od command has the following restrictions: You cannot
use the command with disks that have a capacity of more
than 4 GB. You cannot specify an offset of more than
(2**32)-1 as a starting point.
[Tru64 UNIX] The -i option displays short words as signed
decimal values. The -i option used to be -s in System V.
The following exit values are returned: All input files
were processed successfully. An error occurred.
To display a file in octal word format, a page at a time,
enter: od a.out | more To translate a file into several
formats at once, enter: od -cx a.out >a.xcd
This writes a.out in hexadecimal format (the -x
option) into the file a.xcd, giving also the ASCII
character equivalent, if any, of each byte (the -c
option). To start in the middle of a file, enter:
od -bcx a.out +100.
This displays a.out in octal-byte, character, and
hexadecimal formats, starting from the 100th byte.
The . (dot) after the offset makes it a decimal
number. Without the (dot), the dump starts from the
64th (100 octal) byte.
ENVIRONMENT VARIABLES [Toc] [Back] The following environment variables affect the execution
of od: Provides a default value for the internationalization
variables that are unset or null. If LANG is unset
or null, the corresponding value from the default locale
is used. If any of the internationalization variables
contain an invalid setting, the utility behaves as if none
of the variables had been defined. If set to a non-empty
string value, overrides the values of all the other internationalization
variables. Determines the locale for the
interpretation of sequences of bytes of text data as characters
(for example, single-byte as opposed to multibyte
characters in arguments). Determines the locale for the
format and contents of diagnostic messages written to
standard error. Determines the location of message catalogues
for the processing of LC_MESSAGES.
Commands: sed(1)
Files: locale(4)
Standards: standards(5)
od(1)
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