    DD(I)                        5/15/74                        DD(I)

    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.

         option values
         if=            input file name; standard input is default
         of=            output file name; standard output is default
         ibs=           input block size (default 512)
         obs=           output block size (default 512)
         bs=            set both input and output block size,  super-
                        seding ibs and obs; also, if no conversion is
                        specified, it is particularly efficient since
                        no copy need be done
         cbs=n          conversion buffer size
         skip=n         skip n input records before starting copy
         count=n        copy only n input records
         conv=ascii     convert EBCDIC to ASCII
              ebcdic    convert 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.  Also a pair of numbers may be
         separated by x to indicate a product.

         Cbs is used only if ascii or ebcdic conversion is specified.
         In  the  former case cbs characters are placed into the con-
         version 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

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    DD(I)                        5/15/74                        DD(I)

         on  the  raw  physical devices because it allows reading and
         writing in arbitrary record sizes.

    SEE ALSO
         cp(I)

    BUGS
         The ASCII/EBCDIC conversion tables are taken  from  the  256
         character  standard  in the CACM Nov, 1968.  It is not clear
         how this relates to real life.

         Newlines are inserted only on conversion to  ASCII;  padding
         is done only on conversion to EBCDIC.  There should be sepa-
         rate options.

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