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DD(1)			    General Commands Manual			 DD(1)

NAME
       dd - convert and	copy a file

SYNOPSIS
       dd [ option value ] ...

DESCRIPTION
       Dd  copies the specified	input file to the specified output with	possi-
       ble conversions.	 The standard input and	output are  used  by  default.
       The  input  and output block size may be	specified to take advantage of
       raw physical I/O.  The options are

       -if f  Open file	f for input.

       -of f  Open file	f for output.

       -ibs n Set input	block size to n	bytes (default 512).

       -obs n Set output block size (default 512).

       -bs n  Set both input and output	block size, superseding	ibs  and  obs.
	      If no conversion is specified, preserve the input	block size in-
	      stead  of	 packing short blocks into the output buffer.  This is
	      particularly efficient since no in-core copy need	be done.

       -cbs n Set conversion buffer size.

       -skip n
	      Skip n input records before copying.

       -iseek n
	      Seek n records forward on	input file before copying.

       -files n
	      Catenate n input files (useful only for magnetic tape or similar
	      input device).

       -oseek n
	      Seek n records from beginning of output file before copying.

       -count n
	      Copy only	n input	records.

       -trunc n
	      By default, dd truncates the  output  file  when	it  opens  it;
	      -trunc 0 opens it	without	truncation.

       -quiet n
	      By default, dd prints the	number of blocks read and written once
	      it is finished.  -quiet 1	silences this summary.

       -conv ascii    Convert EBCDIC to	ASCII.

	    ebcdic   Convert ASCII to EBCDIC.

	    ibm	     Like ebcdic but with a slightly different character map.

	    block    Convert variable length ASCII records to fixed length.

	    unblock  Convert fixed length ASCII	records	to variable length.

	    lcase    Map alphabetics to	lower case.

	    ucase    Map alphabetics to	upper case.

	    swab     Swap every	pair of	bytes.

	    noerror  Do	not stop processing on an error.

	    sync     Pad every input record to ibs bytes.

       Where sizes are specified, a number of bytes is expected.  A number may
       end  with  or  to specify multiplication	by 1024	or 512 respectively; a
       pair of numbers may be separated	by to indicate	a  product.   Multiple
       conversions may be specified in the style:

       is  used	only if	or conversion is specified.  In	the first two cases, n
       characters are copied into the conversion buffer, any specified charac-
       ter mapping is done, trailing blanks are	trimmed	and new-line is	 added
       before  sending	the  line  to  the output.  In the latter three	cases,
       characters are read into	the conversion buffer and blanks are added  to
       make up an output record	of size	n.  If is unspecified or zero, the and
       options	convert	the character set without changing the block structure
       of the input file; the and options become a simple file copy.

SOURCE
       /src/cmd/dd.c

SEE ALSO
       cp((1))

DIAGNOSTICS
       Dd reports the number of	full + partial input and  output  blocks  han-
       dled.

									 DD(1)

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