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DD(1)											    DD(1)

       dd - convert and copy a file

       dd [option=value] ...

       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.

       option	      values
       if=	      input file name; standard input is default
       of=	      output file name; standard output is default
       ibs=n	      input block size n bytes (default 512)
       obs=n	      output block size (default 512)
       bs=n	      set  both input and output block size, superseding ibs and obs; also, if no
		      conversion is specified, it is particularly efficient since no copy need be
       cbs=n	      conversion buffer size
       skip=n	      skip n input records before starting copy
       files=n	      copy n files from (tape) input
       seek=n	      seek n records from beginning of output file before copying
       count=n	      copy only n input records
       conv=ascii     convert EBCDIC to ASCII
	    ebcdic    convert ASCII to EBCDIC
	    ibm       slightly different map of ASCII to EBCDIC
	    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
	    ... , ... several comma-separated conversions

       Where sizes are specified, a number of bytes is expected.  A number may end with k, b or w
       to specify multiplication by 1024, 512, or 2 respectively; a pair of numbers may be  sepa-
       rated by x to indicate a product.

       Cbs is used only if ascii or ebcdic conversion is specified.  In the former case cbs char-
       acters are placed into the conversion buffer, converted	to  ASCII,  and  trailing  blanks
       trimmed	and  new-line  added  before  sending the line to the output.  In the latter case
       ASCII characters are read into the conversion buffer,  converted  to  EBCDIC,  and  blanks
       added to make up an output record of size cbs.

       After completion, dd reports the number of whole and partial input and output blocks.

       For example, to read an EBCDIC tape blocked ten 80-byte EBCDIC card images per record into
       the ASCII file x:

	      dd if=/dev/rmt0 of=x ibs=800 cbs=80 conv=ascii,lcase

       Note the use of raw magtape.  Dd is especially suited to I/O on the raw	physical  devices
       because it allows reading and writing in arbitrary record sizes.

       To  skip  over  a  file	before	copying  from magnetic tape do (dd of=/dev/null; dd of=x)

       cp(1), tr(1)

       f+p records in(out): numbers of full and partial records read(written)

       The ASCII/EBCDIC conversion tables are taken from the 256 character standard in	the  CACM
       Nov,  1968.  The `ibm' conversion, while less blessed as a standard, corresponds better to
       certain IBM print train conventions.  There is no universal solution.

       Newlines are inserted only on conversion to ASCII; padding is done only on  conversion  to
       EBCDIC.	These should be separate options.

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