Reference: dd

dd

dd [option=value]

bs=n

cbs=n

conv=flags

`ascii`
`asciib`	EBCDIC to ASCII, using BSD-compatible conversions. Solaris only.
`ebcdic`	ASCII to EBCDIC.
`ebcdicb`
`ibm`
`ibmb`
`block`
`unblock`	Fixed-length records to variable-length.
`lcase`	Uppercase to lowercase.
`ucase`
`noerror`
`notrunc`
`swab`
`sync`	Pad input blocks to `ibs`.

count=n

Copy only n input blocks.

files=n

ibs=n

if=file

obs=n

of=file

Write output to file (default is standard output).

iseek=n

Seek n blocks from start of input file (like skip but more efficient for disk file input).

oseek=n

seek=n

skip=n

Convert an input file to all lowercase:

dd if=caps_file of=small_file conv=lcase

Retrieve variable-length data; write it as fixed-length to out:

data_retrieval_cmd | dd of=out conv=sync,block