DD(1)                                                       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.

          option          values
          if=file         input file name; standard input is default
          of=file         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, super-
                          seding ibs and obs; also, if no conversion
                          is specified, preserve the input block size
                          instead of packing short blocks into the
                          output buffer.  This is particularly effi-
                          cient since no in-core copy need be done.
          cbs=n           conversion buffer size
          skip=n          skip n input records before starting copy
          files=n         copy and concatenate n input files before
                          terminating (makes sense only where input is
                          a magtape or similar device).
          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
               block      convert variable length ASCII records to
                          fixed length
               unblock    convert fixed length ASCII records to vari-
                          able 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
               ... , ...  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.

     DD(1)                                                       DD(1)

          Cbs is used only if ascii, unblock, ebcdic, ibm, or block
          conversion is specified.  In the first two cases, cbs char-
          acters 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 conver-
          sion buffer and blanks are added to make up an output record
          of size cbs. If cbs is unspecified or zero, the ascii,
          ebcdic, and ibm options convert the character set without
          changing the block structure of the input file; the unblock
          and block options become a simple file copy.

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

     EXAMPLE
          dd  if=/dev/rmt0  of=x  ibs=800  cbs=80  conv=ascii,lcase
               Read an EBCDIC tape blocked ten 80-byte EBCDIC card
               images per record into an ASCII file.  Note the use of
               raw magtape to handle arbitrary record sizes.

     SEE ALSO
          cp(1), tar(1), cpio(1)

     DIAGNOSTICS
               f+p records in(out) numbers of full and partial records
          read(written) .}f

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