od(1) General Commands Manual od(1)
NAME
od, xd - octal and hexadecimal dump
SYNOPSIS
address_base] skip] count] type_string] ... [file ...]
address_base] skip] count] type_string] ... [file ...]
Supported Pre-POSIX Usage
[file] offset
[file] offset
DESCRIPTION
and concatenate one or more input files and write their contents to standard output in a user-specified format. If file is not specified,
the standard input is used.
Options and Arguments
and recognize the following options and command-line arguments:
Specify the input offset base.
address_base is a single character that defines which format the offset base is written in:
Decimal format.
Octal format.
Hexadecimal format.
Do not write the offset.
Jump over skip bytes from the beginning of the input. seeks past the first skip bytes in the concatenated input files. If
the combined input is not at least skip bytes long, writes a diagnostic message to standard error and exits with a
non-zero exit status. By default, skip is interpreted as a decimal number. If skip has a leading or it is inter-
preted as a hexadecimal number; a leading indicates that skip is an octal number.
If the value of skip is followed by a or it is interpreted as a multiple of 512, 1024, or 1048576, respectively.
Format no more than
count bytes of input.
By default, count is interpreted as a decimal number. A leading or indicates that count is a hexadecimal number;
a leading identifies an octal value.
If count bytes of input are not available (after successfully skipping if is specified), the input that is avail-
able is formatted.
type_string is a string defining the types to be used when writing the input data.
The string can contain any of the following type-specification characters:
named character ,
character ,
signed decimal ,
floating point ,
octal ,
unsigned decimal ,
hexadecimal ,
Type specification characters and can be followed by an optional unsigned decimal integer specifying the number of
bytes to be transformed by each instance of the output type, or by an optional or indicating that the conversion
should be applied to an item of type char, short, int, or long, respectively.
Type specification character can be followed by an optional or indicating that the conversion should be applied to
an item of type float, double, or long double, respectively.
Multiple types can be concatenated within the same type_string and multiple options can be specified. Output
lines are written for each type specified in the order in which the type specification characters appear.
Write all input data.
Without the option, any number of groups of output lines, that would be identical to the immediately preceding
group of output lines (except for the byte offsets), are replaced with a line containing only an asterisk
file Pathname of one or more input files to be processed. If file is not specified, the standard input is used.
Input files can be any file type.
DESCRIPTION OF PRE-POSIX USAGE
and dump file in one or more formats as selected by the first argument. If the first argument is missing, the default is for for An offset
field is inserted at the beginning of each line. For the offset is in octal, for the offset is in hexadecimal.
Options
and recognize the following format options:
Interpret bytes in octal (hexadecimal).
Interpret bytes in
ASCII. Certain non-graphic characters appear as C escapes: others appear as 3-digit octal numbers.
Interpret 16-bit words in decimal.
Interpret 16-bit words in octal.
Interpret 16-bit words in signed decimal.
Interpret 16-bit words in hexadecimal.
file specifies which file is to be dumped. If file is not specified, the standard input is used.
offset specifies the offset in the file where dumping is to commence, and is normally interpreted as octal bytes. Interpretation can be
altered as follows:
o offset must be preceded by if the file argument is omitted.
o offset preceded by is interpreted in hexadecimal.
o offset followed by is interpreted in decimal.
o offset followed by is interpreted in blocks of 512 bytes.
Dumping continues until end-of-file.
EXAMPLES
Write hexadecimal bytes and the corresponding octal values to the standard output in blocks of 16 bytes in one line, by transforming the
data from the input file
The following commands write one line each of the types character, signed decimal integer, and float, in the order given, transforming 100
bytes of data starting from fifteenth byte offset in the file
Write one line each of the types unsigned integer, named character, and long double, with the offsets written in hexadecimal and forcing a
write, even on lines that are identical to the immediately preceding group of output lines:
WARNINGS
When the output format is of floating-point type (using the or options), the following actions occur:
o If the input bytes cannot be transformed into a valid floating point number, a floating point exception might occur. In that
case, the output is printed as a string containing some non-numeric characters and program execution continues.
o When the number of input bytes used for transformation is set to 1 with the type specifier characters or only the least-signifi-
cant seven bits of each byte are used.
o When one or more of the or options is specified, an operand starting with the first character as a plus-sign or the first charac-
ter as numeric is interpreted as a file name.
(UNIX Standard only, see standards(5). Multiple types can be specified by using multiple options. Output lines are written for each type
specified in the order in which the types are specified.)
EXTERNAL INFLUENCES
For information about the UNIX standard environment, see standards(5).
Environment Variables
provides a default value for the internationalization variables that are unset or null. If is unset or null, the default value of "C" (see
lang(5)) is used. If any of the internationalization variables contains an invalid setting, will behave as if all internationalization
variables are set to "C". See environ(5).
If set to a non-empty string value, overrides the values of all the other internationalization variables.
determines the interpretation of text as single and/or multi-byte characters, the classification of characters as printable, and the char-
acters matched by character class expressions in regular expressions.
determines the locale that should be used to affect the format and contents of diagnostic messages written to standard error and informa-
tive messages written to standard output.
determines the location of message catalogues for the processing of
International Code Set Support
Single- and multi-byte character code sets are supported. Multi-byte data is displayed as multi-byte values.
RETURN VALUE
Exit values are:
Successful completion.
Error condition occurred.
SEE ALSO
adb(1), standards(5).
STANDARDS CONFORMANCE
od(1)