od(1) General Commands Manual od(1)
NAME
od - Writes the contents of a file to standard output
SYNOPSIS
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 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 standards 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 set-
ting 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. Dis-
plays 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 hexa-
decimal 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, respec-
tively. If b is appended to a skip interpreted as hexadecimal, it is recognized as the last digit of the skip, not a block indica-
tor. 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 con-
version. [Tru64 UNIX] Indicates odd parity on -a conversion. [Tru64 UNIX] Looks for strings of ASCII graphic characters, termi-
nated 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, form-
feed, 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 num-
ber 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 indi-
cated 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. Dis-
plays 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 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 pseu-
doaddress 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 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.
NOTES
[Tru64 UNIX] The -i option displays short words as signed decimal values. 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: 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.
SEE ALSO
Commands: sed(1)
Files: locale(4)
Standards: standards(5)
od(1)
