#!/bin/csh -f

#############################################################################
# Copyright: J.Brewer/ESO 1999.##############################################
#############################################################################
#
# Name: tape2disk
# Description:  This script reads files from a tape that were written with the
# wfits shell script, using the `dd' option.
#
# Note: if using Sun Unix, change `mt -t' to `mt -f'...
#
#
# Author:  James Brewer, jbrewer@eso.org
# Version: 1.0, 5 May99: First release
#
#############################################################################


#
# Check script arguments...
#
if($#argv != 3 || $1 == "-help") then
  goto error
endif


#
# Set variables...
#
set mt   = "mt -t"	# -t: SunOS, -f: HP
set bl   = 28800	# blocksize to read from tape...
set root = TAPE		# Root name for files...
set ext  = fits		# extension to be used...


#
# Define action on interrupt (^c)...
#
onintr cleanup


#
# Check that the tape drive can be read from...
#
if !(-r $1) then
   echo $0": Couldn't find drive "$1" on this machine..."
   exit(-1)
endif


#
# Check that file names to be used are `vacant'...
#
@ n=1
while ($n <= $2)
  set op = $root`printf "%03d" $n`.$ext
  if (-e $op) then
    echo $0": a file named "$op" already exists. No action taken..."
    exit (-1)
  endif
  @ n+=1
end


#
# Start loop to extract the files...
#
@ n=1
while ($n <= $2)

  #
  # Set the output name, and read the file...
  #
  set op = $root`printf "%03d" $n`.$ext
  echo " "
  echo "Reading file "$op
  dd if=$1 of=$op bs=$bl

  #
  # Check status to see if dd executed successfully...
  #
  if($status != 0) then
    echo "Problem with the dd command. (End of tape, incorrect bs?)"
    goto cleanup
  endif


  #
  # Check the size of the new file...
  #
  set size = `ls -l $op | tr -s ' ' | cut -f5 -d ' '`
  if ($size == 0) then 
    echo $0": "$op" is an empty file -- end of tape reached?"
    goto cleanup
  endif


  #
  # If option specified, attempt to restore original filename...
  #
  if ($3 == 'y' || $3 == 'Y') then
    RestoreID $op
  endif

  @ n+=1
end


cleanup:

  #
  # Tape handling options...
  #
  echo " "
  echo "Choose:"
  echo "    r -- Rewind "
  echo "    o -- Rewind, take drive offline"
  echo "    x -- Do nothing (default)"
  echo " "
  echo -n "Enter your choice... "
  set reply = $<
  if ($reply == 'r') then
    echo "Rewinding tape..."
    $mt $1 rew
  endif
  if ($reply == 'o') then
    echo "Taking tape offline..."
    $mt $1 offline
  endif

  exit(0)


error:
  echo "Usage: "$0" drive number rename"
  echo " drive:  Name of tape drive, e.g. /dev/rmt/0bn"
  echo " number: Number of files to read"
  echo " rename: Restore original names (y/n)"
  echo " "
  echo "[Further information  -->   "$0" -help]"
  echo "[See this script      -->  more `which "$0"`]"
 
  if($1 == "-help") then
    more `echo $0 | sed -e s/tape2disk/ObsLog.man/`
  endif
 
  exit(-1)