SYNOPSIS

       copytape f] t] snnn] lnnn] v] ]

DESCRIPTION

       copytape  duplicates  magtapes.   It  is  intended  for  duplication of
       bootable or other non-file-structured (non-tar-structured) magtapes  on
       systems  with  only one tape drive.  copytape is blissfully ignorant of
       tape formats.  It merely makes a bit-for-bit copy of its input.

       In normal use, copytape would be run twice.   First,  a  boot  tape  is
       copied  to  an intermediate disk file.  The file is in a special format
       that preserves the record boundaries and tape  marks.   On  the  second
       run,  copytape  reads  this  file and generates a new tape.  The second
       step may be repeated if multiple  copies  are  required.   The  typical
       process would look like this:

            tutorial% copytape /dev/rmt8 tape.tmp
            tutorial% copytape tape.tmp /dev/rmt8
            tutorial% rm tape.tmp

       copytape  copies from the standard input to the standard output, unless
       input and output arguments are provided.  It will automatically  deter-
       mine  whether  its  input and output are physical tapes, or data files.
       Data files are encoded in a special (human-readable) format.

       Since copytape will automatically determine  what  sort  of  thing  its
       input  and  output are, a twin-drive system can duplicate a tape in one
       pass.  The command would be
            tutorial% copytape /dev/rmt8 /dev/rmt9

OPTIONS

       -snnn
          Skip tape marks.  The specified number of tape marks are skipped  on
          the  input  tape,  before  the  copy begins.  By default, nothing is
          skipped, resulting in a copy of the complete input  tape.   Multiple
          tar(1)  and dump(1) archives on a single tape are normally separated
          by a single tape mark.  On ANSI or IBM labelled tapes, each file has
          three associated tape marks.  Count carefully.

       -lnnn
          Limit.   Only nnn files (data followed by a tape mark), at most, are
          copied.  This can be used to terminate a copy early.   If  the  skip
          option is also specified, the files skipped do not count against the
          limit.

       -f From tape.  The input is treated as though it were a physical  tape,
          even  if  it is a data file.  This option can be used to copy block-
          structured device files other than magtapes.

       -t To tape.  The output is treated as though it were a  physical  tape,
          even  if it is a data file.  Normally, data files mark physical tape
          blocks with a (human-readable) header describing the block.  If  the

SEE ALSO

       ansitape(1), dd(1), tar(1), mtio(4), copytape(5)

AUTHOR

       David  S.  Hayes, Site Manager, US Army Artificial Intelligence Center.
       Originally developed September 1984 at  Rensselaer  Polytechnic  Insti-
       tute, Troy, New York.  Revised July 1986.  This software is in the pub-
       lic domain.

BUGS

       copytape treats two successive file marks as logical end-of-tape.

       The intermediate data file can consume huge amounts of disk  space.   A
       2400-foot  reel  at  6250-bpi  can  burn  140  megabytes.   This is not
       strictly speaking a bug, but users should be aware of the  possibility.
       Check disk space with df(1) before starting copytape.  Caveat Emptor!

       A  256K  buffer is used internally.  This limits the maximum block size
       of the input tape.



                                 25 June 1986                      COPYTAPE(1)