od writes an unambiguous representation of each file (‘-’ means standard input), or standard input if none are given. Synopses:
od [option]... [file]... od [-abcdfilosx]... [file] [[+]offset[.][b]] od [option]... --traditional [file] [[+]offset[.][b] [[+]label[.][b]]]
Each line of output consists of the offset in the input, followed by
groups of data from the file. By default, od prints the offset in
octal, and each group of file data is a C
short int's worth of input
printed as a single octal number.
If offset is given, it specifies how many input bytes to skip before formatting and writing. By default, it is interpreted as an octal number, but the optional trailing decimal point causes it to be interpreted as decimal. If no decimal is specified and the offset begins with ‘0x’ or ‘0X’ it is interpreted as a hexadecimal number. If there is a trailing ‘b’, the number of bytes skipped will be offset multiplied by 512.
If a command is of both the first and second forms, the second form is assumed if the last operand begins with ‘+’ or (if there are two operands) a digit. For example, in ‘od foo 10’ and ‘od +10’ the ‘10’ is an offset, whereas in ‘od 10’ the ‘10’ is a file name.
The program accepts the following options. Also see Common options.
The default is octal.
‘b’ => 512 ("blocks") ‘KB’ => 1000 (KiloBytes) ‘K’ => 1024 (KibiBytes) ‘MB’ => 1000*1000 (MegaBytes) ‘M’ => 1024*1024 (MebiBytes) ‘GB’ => 1000*1000*1000 (GigaBytes) ‘G’ => 1024*1024*1024 (GibiBytes)
and so on for ‘T’, ‘P’, ‘E’, ‘Z’, and ‘Y’.
bytesare interpreted as for the -j option.
If bytes is omitted with --strings, the default is 3.
Adding a trailing “z” to any type specification appends a display of the ASCII character representation of the printable characters to the output line generated by the type specification.
a outputs things like ‘sp’ for space, ‘nl’ for
newline, and ‘nul’ for a zero byte. Only the least significant
seven bits of each byte is used; the high-order bit is ignored.
‘ ’, ‘\n’, and
Except for types ‘a’ and ‘c’, you can specify the number of bytes to use in interpreting each number in the given data type by following the type indicator character with a decimal integer. Alternately, you can specify the size of one of the C compiler's built-in data types by following the type indicator character with one of the following characters. For integers (‘d’, ‘o’, ‘u’, ‘x’):
For floating point (
ninput bytes per output line. This must be a multiple of the least common multiple of the sizes associated with the specified output types.
If this option is not given at all, the default is 16. If n is omitted, the default is 32.
The next several options are shorthands for format specifications. GNU od accepts any combination of shorthands and format specification options. These options accumulate.
od --traditional [file] [[+]offset[.][b] [[+]label[.][b]]]
can be used to specify at most one file and optional arguments specifying an offset and a pseudo-start address, label. The label argument is interpreted just like offset, but it specifies an initial pseudo-address. The pseudo-addresses are displayed in parentheses following any normal address.
An exit status of zero indicates success, and a nonzero value indicates failure.