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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 possible
     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 instead 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 in-
	    put 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  character
     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 handled.

									   DD(1)

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