Content-type: text/html Man page of od

od

Section: User Commands (1)
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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 specified 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:  XPG4, XPG4-UNIX

Refer to the standards(5) reference page for more information about industry standards and associated tags.
 

OPTIONS

Format characters are as follows: [Compaq]  Displays quadwords as hexadecimal values. This option applies only to the operating system for Alpha AXP systems. [Compaq]  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. [Compaq]  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 [Compaq]  Alarm (or bell) Backspace Formfeed Newline character Enter Tab [Compaq]  Vertical tab

Other nongraphic characters appear as 3-digit octal numbers. Bytes with the parity bit set are displayed in octal. [Compaq]  Displays any extended characters as standard printable ASCII characters using the appropriate character escape string. Displays short words as unsigned decimal values. [Compaq]  Displays long words as unsigned decimal values. [Compaq]  Displays long words as double-precision, floating-point. (Same as -F.) [Compaq]  Displays long words as single-precision, floating-point. [Compaq]  Displays long words as double-precision, floating-point. [Compaq]  Displays short words as unsigned hexadecimal values. [Compaq]  Displays long words as unsigned hexadecimal values. [Compaq]  Displays short words as signed decimal values. [Compaq]  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, respectively. If b is appended to a skip interpreted as hexadecimal, 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. [Compaq]  Displays long words as unsigned octal values. [Compaq]  Indicates even parity on -a conversion. [Compaq]  Indicates odd parity on -a conversion. [Compaq]  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 values.
[Compaq]  If the environment variable CMD_ENV is set to xpg4, action is the same as using the -i option. [Compaq]  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 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 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 indicated with an * (asterisk) in column 1. [Compaq]  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.) [Compaq]  Displays long words as unsigned hexadecimal values. (Same as -H.)

[Compaq]  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 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 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

[Compaq]  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)


 

Index

NAME
SYNOPSIS
STANDARDS
OPTIONS
OPERANDS
DESCRIPTION
RESTRICTIONS
NOTES
EXIT STATUS
EXAMPLES
ENVIRONMENT VARIABLES
SEE ALSO

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Time: 02:42:46 GMT, October 02, 2010