#!/bin/ksh
#h scotar - version 1.7
#h Extracts files from a multi-volume tar created on SCO Xenix/Unix
#h onto Linux or other non-SCO platforms.
#h
#h usage:   scotar [ help | <device> ]
#h	<device> defaults to /dev/fd0
#h
#h Run scotar, put the first floppy in the drive and press [enter].
#h Put subsequent floppies in when prompted.
#h When scotar asks for a volume number that is higher than your final one,
#h leave the drive _empty_ and press [enter] one last time.
#h 
#h Notes: 
#h - The original time-stamps are lost on any files that span volumes. This is
#h   possible to fix at some point by using stat and touch.
#h - Screws up if you don't follow the prompt directions exactly. (you can
#h always just re-run if you think you made a mistake.)
#h
#h history:
#h	1.0 initial release, tested, works, requires bash-2.x
#h	1.1 untested, port to ksh for portability
#h	1.2 untested, added help (using "scripthelp"),
#h          removed "how many volumes" prompt
#h      1.3 untested, greatly simplified, probable bug fix, commented code
#h	1.4 *tested!*, changed wording of prompt to try and avoid reading last
#h	    disk more than once. fixed minor help bug.
#h	    hopefully the goal of portability is realised now.
#h	1.5 fixed problem with absolute paths.
#h	1.6 removed some pointless file-shuffling
#h	1.7 added comments
#h          added more and better debug output
#h          attempt sco behviour with extracting absolute paths
#h
#h Brian K. White - brian@aljex.com - Aljex Software - July 28 2001

case $1 in
    h|-h|help|--help) scripthelp $0 ;exit ;;
    "") d=/dev/fd0 ;;
    *) d=$1 ;;
esac

# "true" or "false" - enable or disable verbose operation
DEBUG=true

echo "+--------------------------------------------------------------+"
echo "| scotar - version 1.7                         brian@aljex.com |"
echo "| Extracts SCO Xenix/Unix multi-volume tars on linux/bsd/other |"
echo "+--------------------------------------------------------------+"

FINISHED=false ; c=1 ; U=ScoTarSav

while true ; do

  # read-in a volume (extract all the files and remember their names)
  echo "\aInsert volume $c or remove final volume, and hit Enter: \c" ; read X
  dd if=$d of=/dev/null bs=1 count=1 >/dev/null 2>&1 && {
    echo "Reading volume $c ...\c"
#    V=`tar xvf $d |sed "s,^/,, ;s,\ /,\ ,g"`
    V=`tar xspPvf $d `
    echo "done"
  } || {
    FINISHED=true
  }

  # if this is not the first volume, then look for file fragments to assemble
  [ $c -gt 1 ] && {
    [ -f $F ] && {
      # if a file exists now with same name as last file in previous volume,
      # then both files are fragments and need to be concatenated together.
      $DEBUG && echo "Reassembling file: $F" 
      cat $F >>$F.$U
    } || {
      # if not, then the last file in the previous volume was not a fragment
      # and it should just be renamed back to it's original name.
      $DEBUG && echo "$F was not a fragment"
    }
    mv -f $F.$U $F
  }

  # if this was the final volume in the set, exit now
  $FINISHED && { echo "Done" ; exit ; }

  # rename the last file from this volume in case it is a fragment
  for F in $V ; do : ; done 
  $DEBUG && echo "Saving possible fragment: $F"
  mv -f $F $F.$U

  # increment counter and proceed to next volume
  c=$((c+1))

done