DD(C)                    XENIX System V                     DD(C)



     Name
          dd - Converts and copies a file.

     Syntax
          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             Value

          if=file            Input filename; standard input is default

          of=file            Output filename; standard output is
                             default

          ibs=n              Input block size n bytes (default is
                             BSIZE block size)

          obs=n              Output block size (default is BSIZE block
                             size)

          bs=n               Sets both input and output block size,
                             superseding ibs and obs; also, if no
                             conversion is specified, it is
                             particularly efficient since no in-core
                             copy needs to be done

          cbs=n              Conversion buffer size

          skip=n             Skips n input records before starting
                             copy

          seek=n             Seeks n records from beginning of output
                             file before copying

          count=n            Copies only n input records

          conv=ascii         Converts EBCDIC to ASCII

          conv=ebcdic        Converts ASCII to EBCDIC

          conv=ibm           Slightly different map of ASCII to EBCDIC

          conv=lcase         Maps alphabetics to lowercase







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     DD(C)                    XENIX System V                     DD(C)



          Option             Value

          conv=ucase         Maps alphabetics to uppercase

          conv=swab          Swaps every pair of bytes

          conv=sync          Pads every input record to ibs

          conv="... , ..."   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
          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
          conversion buffer, converted to ASCII, and trailing blanks
          trimmed and newline 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.

     Examples
          This command reads an EBCDIC tape, blocked ten 80-byte
          EBCDIC card images per record, into the ASCII file outfile:

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

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

     See Also
          copy(C), cp(C), tar(C)

     Diagnostics
          f+p records in(out)     Numbers of full and partial records
                                  read(written)

     Notes
          The ASCII/EBCDIC conversion tables are taken from the 256-
          character standard in the CACM Nov, 1968.  The ibm
          conversion 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.




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