[ Previous | Next | Table of Contents | Index | Library Home |
Legal |
Search ]
Commands Reference, Volume 4
Displays files in a specified
format.
od [ -v ] [
-A AddressBase ] [ -N Count ] [ -j Skip ] [ -t TypeString ... ]
[ File ... ]
od [ -a ] [ -b ] [ -c ] [ -C ] [ -d ] [ -D ] [ -e ] [ -f ] [ -F ] [ -h ] [ -H ] [ -i ] [ -I ] [ -l ] [ -L ] [ -o ] [ -O ] [ -p ] [ -P ] [ -s ] [ -v ] [ -x ] [ -X ] [ [ -S [ N ] ]
[ -w [ N ] ]
[ File ]
[ [ + ] Offset
[ . | b | B ]
[ + ] Label [ . | b | B ] ]
The od command
displays the file specified by the File parameter in the format
specified. If the File parameter is not given, the
od command reads standard input. Multiple types can be
specified by using multiple -bcCDdFfOoSstvXx options.
In the first syntax format, the
output format is specified by the -t flag. If no format type
is specified, -t o2 is the default.
In the second syntax format, the
output format is specified by a combination of flags. The
Offset parameter specifies the point in the file where the file
output begins. By default, the Offset parameter is
interpreted as octal bytes. If the . (dot) suffix is
appended, the parameter is interpreted as a decimal; if the parameter
begins with a leading x or 0x, it is treated as a
hexadecimal. If the b suffix is added to the parameter, it
is interpreted in blocks of 512 bytes; if the B suffix is
added to the parameter, it is interpreted in blocks of 1024 bytes.
The Label parameter is
interpreted as a pseudo-address for the first byte displayed. If used,
it is given in ( ) (parentheses) following the Offset
parameter. The suffixes have the same meanings as for the
Offset parameter.
When the od command
reads standard input, the Offset parameter and the Label
parameter must be preceded by a + (plus sign).
The setting of environment
variables such as LANG and LC_ALL affects the operation
of the od command. See "Understanding
Locale Environment Variables" in AIX 5L Version 5.1 System
Management Guide: Operating System and Devices for more
information.
The flags for the first format
are:
-A AddressBase
| Specifies the input offset base. The AddressBase
variable is one of the following characters:
- d
- Offset base is written in decimal.
- o
- Offset base is written in octal.
- x
- Offset base is written in hexadecimal.
- n
- Offset base is not displayed.
Unless -A n is specified, the output line will be preceded by
the input offset, cumulative across input files, of the next byte to be
written. In addition, the offset of the byte following the last byte
written will be displayed after all the input data has been processed.
Without the -A address_base option and the [offset_string] operand,
the input offset base is displayed in octal.
|
-j Skip
|
Jumps over the number of bytes given by the Skip variable before
beginning to display output. If more than one file is specified, the
od command jumps over the designated number of bytes of the
concatenated input files before displaying output. If the combined
input is not at least the length of the skip bytes, the od command
will write a diagnostic message to standard error and exit non-zero
status.
By default, the value of the Skip variable is interpreted as a
decimal number. With a leading 0x or 0X, the offset is interpreted as a
hexadecimal number; otherwise, with a leading 0, the offset shall be
interpreted as an octal number. If the characters b,
k, or m are appended to the number contained by the
Skip variable, the offset is equal to the value, in bytes, of the
Skip variable multiplied by 512, 1024, or 1024*1024,
respectively.
|
-N Count
| Formats no more than the number of input bytes specified by the
Count variable. By default, the value of the
Count variable is interpreted as a decimal number. With a
leading 0x or 0X, it is treated as a hexadecimal number. If it begins
with a 0, it is treated as an octal number. The base of the address
displayed is not implied by the base of the Count
option-argument.
|
-t
TypeString
| Specifies the output type. The TypeString variable is a
string specifying the types to be used when writing out data. Multiple
types can be concatenated within the same TypeString variable, and
the -t flag can be specified more than once. Output lines
are written for each type specified, in the order in which the type
specification characters are given. The TypeString variable
can consist of the following characters:
- a
- Displays bytes as named characters. Bytes with the least seven bits
in the range of 0 through 01777 are written using the corresponding names for
those characters.
- c
- Displays bytes as characters. The number of bytes transformed by
the c type string is determined by the LC_CTYPE local
category. Printable multibyte characters are written in the area
corresponding to the first byte of the character; the two character
sequence ** is written in the area corresponding to each remaining
byte in the character, as an indication that the character is
continued. The following nongraphic characters are used as C-language
escape sequences:
\ Backslash
\a Alert
\b Backspace
\f Form-feed
\n New-line character
\0 Null
\r Carriage return
\t Tab
\v Vertical tab
|
|
- d
- Displays bytes as signed decimals. By default, the od
command transforms the corresponding number of bytes in the C-language type
int. The d type string can be followed by an
unsigned decimal integer that specifies the number of bytes to be transformed
by each instance of the output type.
An optional C, I, L, or S
character can be appended to the d option, indicating that the
conversion should be applied to an item of type char,
int, long, or short, respectively.
- f
- Displays bytes as floating points. By default, the od
command transforms the corresponding number of bytes in the C-language type
double. The f type string can be followed by an
unsigned decimal integer that specifies the number of bytes to be transformed
by each instance of the output type.
An optional F, D, or L character can be
appended to the f option, indicating that the conversion should be
applied to an item of type float, double, or
long double, respectively.
|
|
- o
- Displays bytes as octals. By default, the od command
transforms the corresponding number of bytes in the C-language type
int. The o type string can be followed by an
unsigned decimal integer that specifies the number of bytes to be transformed
by each instance of the output type.
An optional C, I, L, or S
character can be appended to the o option, indicating that the
conversion should be applied to an item of type char,
int, long, or short, respectively.
|
|
- u
- Display bytes as unsigned decimal. By default, the od
command transforms the corresponding number of bytes in the C-language type
int. The u type string can be followed by an
unsigned decimal integer that specifies the number of bytes to be transformed
by each instance of the output type.
An optional C, I, L, or S
character can be appended to the u option, indicating that the
conversion should be applied to an item of type char,
int, long, or short, respectively.
- x
- Display bytes as hexadecimal. By default, the od command
transforms the corresponding number of bytes in the C-language type
int. The x type string can be followed by an
unsigned decimal integer that specifies the number of bytes to be transformed
by each instance of the output type.
An optional C, I, L, or S
character can be appended to the x option, indicating that the
conversion should be applied to an item of type char,
int, long, or short, respectively.
|
The flags for the second format
are:
-a
| Displays bytes as characters and displays them with their ASCII
names. If the -p flag is also given, bytes with even parity
are underlined. The -P flag causes bytes with odd parity to
be underlined. Otherwise, parity is ignored.
|
-b
| Displays bytes as octal values.
|
-c
| Displays bytes as ASCII characters. The following nongraphic
characters appear as C-language escape sequences:
\ Backslash
\a Alert
\b Backspace
\f Form-feed
\n New-line character
\0 Null
\r Carriage return
\t Tab
\v Vertical tab
Others appear as three-digit
octal numbers.
|
-C
| Displays extended characters as standard printable ASCII characters
(using the appropriate character escape string) and displays multibyte
characters in hexadecimal form.
|
-d
| Displays 16-bit words as unsigned decimal values.
|
-D
| Displays long words as unsigned decimal values.
|
-e
| Displays long words as double-precision, floating point. (same as
the -F flag)
|
-f
| Displays long words as floating points.
|
-F
| Displays long words as double-precision, floating point. (same as
the -e flag)
|
-h
| Displays 16-bit words as unsigned hexadecimal.
|
-H
| Displays long words as unsigned hexadecimal values.
|
-i
| Displays 16-bit words as signed decimal.
|
-I
| (Uppercase i) Displays long words as signed decimal values.
|
-l
| (Lowercase L) Displays long words as signed decimal values.
|
-L
| Displays long words as signed decimal values.
|
Note: The
flags -I (uppercase i), -l (lowercase L), and
-L are identical.
-o
| Displays 16-bit words as unsigned octal.
|
-O
| Displays long words as unsigned octal values.
|
-p
| Indicates even parity on -a conversion.
|
-P
| Indicates odd parity on -a conversion.
|
-s
| Displays 16-bit words as signed decimal values.
|
-S[N]
| Searches for strings of characters ending with a null byte. The
N variable specifies the minimum length string to be
recognized. If the N variable is omitted, the minimum length
defaults to 3 characters.
|
The -v flag is the
same for both formats:
-v
| Writes all input data. By default, output lines that are identical
to the immediately preceding output lines are not printed, but are replaced
with a line containing only an * (asterisk). When the -v
flag is specified, all the lines are printed.
|
-w [N]
| Specifies the number of input bytes to be interpreted and displayed on
each output line. If the -w flag is not specified, 16 bytes
are read for each display line. If the -w flag is specified
without the N variable, 32 bytes are read for each display
line. The maximum input value is 4096 bytes. Input values
greater than 4096 bytes will be reassigned the maximum value.
|
-x
| Displays 16-bit words as hexadecimal values.
|
-X
| Displays long words as unsigned hexadecimal values. (same as the
-H flag)
|
This command returns the
following exit values:
0
| All input files were processed successfully.
|
>0
| An error occurred.
|
- To display a file in octal, a
page at a time, enter:
od a.out | pg
This command displays the a.out file in octal format
and pipes the output through the pg command.
- To translate a file into
several formats at once, enter:
od -t cx a.out > a.xcd
This command writes the contents of the a.out file, in
hexadecimal format ( x) and character format
( c), into the a.xcd
file.
- To start displaying a file in
the middle (using the first syntax format), enter:
od -t acx -j 100 a.out
This command displays the a.out file in named character
( a), character ( c), and hexadecimal ( x) formats, starting from the 100th byte.
- To start in the middle of a
file (using the second syntax format), enter:
od -bcx a.out +100.
This displays the a.out file in octal-byte ( -b), character ( -c), and hexadecimal ( -x) formats, starting from the 100th
byte. The . (period) after the offset makes it a
decimal number. Without the period, the output would start from the
64th (100 octal) byte.
/usr/bin/od
| Contains the od command.
|
The dbx command, pg command.
The National
Language Support Overview for System Management and
Understanding Locale Environment Variables in AIX 5L Version
5.1 System Management Guide: Operating System and
Devices.
[ Previous | Next | Table of Contents | Index |
Library Home |
Legal |
Search ]