od(1)od(1)NAMEod - Writes the contents of a file to standard output
SYNOPSISod [-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 speci‐
fied by the first option. If you do not specify the first option, the
-o option is the default.
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
od: XCU5.0
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
OPTIONS
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 New‐
line 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-pre‐
cision, 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] Dis‐
plays short words as signed decimal values. [Tru64 UNIX] Dis‐
play 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 hexa‐
decimal, 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 val‐
ues.
[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 specifi‐
cation characters: Named character Character Signed decimal
Floating point Octal Unsigned decimal Hexadecimal
The type specification characters d, f, o, u, and x can be fol‐
lowed 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 com‐
mand 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.
OPERANDS
A path name of a file to be written. If no file operands are speci‐
fied, 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 off‐
set, it is interpreted in decimal. If offset begins with x or 0x, it
is interpreted in hexadecimal. If b (B) is appended to a nonhexadeci‐
mal 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 inter‐
preted 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.
DESCRIPTION
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.
RESTRICTIONS
The od command has the following restrictions: You cannot use the com‐
mand 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.
NOTES
[Tru64 UNIX] The -i option displays short words as signed decimal val‐
ues. The -i option used to be -s in System V.
EXIT STATUS
The following exit values are returned: All input files were processed
successfully. An error occurred.
EXAMPLES
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
The following environment variables affect the execution of od: Pro‐
vides 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 vari‐
ables contain an invalid setting, the utility behaves as if none of the
variables had been defined. If set to a non-empty string value, over‐
rides 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 multi‐
byte characters in arguments). Determines the locale for the format
and contents of diagnostic messages written to standard error. Deter‐
mines the location of message catalogues for the processing of LC_MES‐
SAGES.
SEE ALSO
Commands: sed(1)
Files: locale(4)
Standards: standards(5)od(1)