Makes a copy of an input file (if=) or standard input if there's no named input file, using the specified conditions, and sends the results to the output file (or standard output if of isn't 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.
dd doesn't preserve resource forks or HFS metadata when copying files that contain them.
Set input and output block size to
n bytes; this option supersedes ibs and obs.
Set the size of the conversion buffer (logical record length) to
n bytes. Use only if the conversion
flag is ascii, asciib, ebcdic, ebcdicb, ibm, ibmb, block, or unblock.
Convert the input according to one or more (comma-separated)
flags listed next. The first six
flags are mutually exclusive. The next two are mutually exclusive with each other, as are the following two.
EBCDIC to ASCII.
EBCDIC to ASCII, using BSD-compatible conversions.
ASCII to EBCDIC.
ASCII to EBCDIC, using BSD-compatible conversions.
ASCII to EBCDIC with IBM conventions.
ASCII to EBCDIC with IBM conventions, using BSD-compatible conversions.
Variable-length records (i.e., those terminated by a newline) to fixed-length records.
Fixed-length records to variable length.
Uppercase to lowercase.
Lowercase to uppercase. ...