Unix in a Nutshell, 4th Edition

Name

dd

Synopsis

    dd [option=value]

Make a copy of an input file (if=), or standard input if no named input file, using the specified conditions, and send the results to the output file (or standard output if of is not specified). Any number of options can be supplied, although if and of are the most common and are usually specified first. Because dd can handle arbitrary block sizes, it is useful when converting between raw physical devices.

Tip

Although dd provides options for ASCII/EBCDIC conversions, iconv is better suited to that task.

Options

bs= n

Set input and output block size to n bytes; this option supersedes ibs and obs.

cbs= n

Set the size of the conversion buffer (logical record length) to n bytes. Use only if the conversion flag is block or unblock, or one of the ASCII/EBCDIC conversions.

conv= flags

Convert the input according to one or more (comma-separated) flags listed below. The first nine flags are mutually exclusive. The next two are mutually exclusive with each other, as are the following two.

ascii	EBCDIC to ASCII.
asciib	EBCDIC to ASCII, using BSD-compatible conversions. Solaris only.
oldascii	EBCDIC to ASCII, using BSD-compatible conversions. Mac OS X only.
ebcdic	ASCII to EBCDIC.
ebcdicb	ASCII to EBCDIC, using BSD-compatible conversions. Solaris only.
oldebcdic	ASCII to EBCDIC, using BSD-compatible conversions. Mac OS X only.
ibm	ASCII to EBCDIC with IBM conventions.
ibmb	ASCII to EBCDIC with IBM conventions, using BSD-compatible ...