#!/bin/sh

# IMPORTANT: You must use a version of mkisofs recent enough that it
#   understands "/foo/=/foo" syntax.

PATH=/usr/local/bin:/bin:/usr/bin
export PATH


display_usage() {
  /bin/cat << 'usage_eof'
Usage:  $0 [options] [paths]
  --help           -h  get help 
  --dryrun         -n  don't do anything; just print actions to take
  --yes            -y  pre-answer all questions "yes" 
  --quiet          -q  quiet mode
  --verbose        -v  verbose mode (not yet implemented)
  --isofs <path>   -i  put ISO-9660 image in <path>, not /backup/backup.iso
  --logfile <path> -l  list CD contents in <path> after creation
  --speed <digit>  -s  speed for cdrecord (default is 1, single speed)
  --device <c,i,l> -d  SCSI device as controller,id,lun (default "0,6,0")
  --exclude <glob> -m  file or directory name to ignore; can appear multiple
                       times.  "cache", ".glimpse", and ".Xauthority" are
                       ignored by default.
  --blank <type>   -b  blank a CD-RW before writing; <type> is "all" or "fast"
  --file <path>    -f  file with lines in the form DIR/=DIR or FILE=FILE which
                       represent files or directories to be written to CD, eg
                       "/etc/=/etc".

Non-option arguments are of the form "CDDIR/=DIR" or "CDFILE=FILE", and will
name files or directories to back up (as for lines in --file's file).  If only
"FILE" or "DIR" is specified, it or its contents will be put in the top level
of the CD.  A path or --file must be given.

No shell metacharacters (spaces, backticks, asterisks, etc.) can appear in a
pathname to be backed up.  ("/my directory/=/my directory" fails.)
usage_eof
}

error() {
  echo $* 1>&2
}

die() {
  error $*
  exit 1
}

usage_die() {
  error "\"$0 --help\" for usage."
  exit 1
}

qecho() {
  if [ "$quiet" = "0" ]
  then
    echo "$@"
  fi
}

process_args() {
  original_args="$@"			# to pass to children (UNUSED)
  really=''				# 'echo' if just testing
  help=0				# 1 -> just display (long) help
  yes=0					# 1 -> noninteractive (go ahead)
  quiet=0				# 1 -> be quiet
  verbose=0				# 1 -> be verbose (UNUSED)
  cdrecord_v=''				# '-v' if $verbose
  mkisofs_v=''				# '-v' if $verbose
  isofs=/backup/backup.iso		# where to create ISO-9660 image
  dev='0,6,0'				# SCSI device to write to (ctlr,id,lun)
  logs=/backup/cdlogs
  speed=1
  excludes='-m cache -m .glimpse -m .Xauthority'	# ignore these dirs
  cdrecord_blank=''
  date=`date '+%Y-%m-%d-%H%M'`
  host=`hostname`
  logfile=''				# name of log file to write
  					#   (default set below)
  dirs=''				# files/dirs to copy
  dirfile=''				# name of file with directories/files
  					#   to copy
  
  # read ./cdbackup.defaults if it exists - can override above definitions
  [ -r ./cdbackup.defaults ] && . ./cdbackup.defaults
  
  arg=$1
  
  if [ $# != "0" ] ; then
    while ( [ -n "$arg" ] )
    do
      case "$arg"
      in
      -h|--help)	help=1;
      			;;
      -n|--dryrun)	really=echo;
  			;;
      -y|--yes)		yes=1;
  			;;
      -q|--quiet)	quiet=1;
  			;;
      -v|--verbose)	verbose=1;
  			;;
      -b|--blank)	cdrecord_blank="blank=$2";
      			shift;
      			;;
      -d|--device)	dev=$2;
      			shift;
      			;;
      -f|--file)	dirfile=$2;
      			shift;
      			;;
      -i|--isofs)	isofs=$2;
  			shift;
  			;;
      -l|--logfile)	logfile=$2;
  			shift;
  			;;
      -m|--exclude)	excludes="$excludes -m '$2'";
  			shift;
  			;;
      -s|--speed)	speed=$2;
  			shift;
  			;;
      -*)		error "$0: unrecognized argument $arg";
      			usage_die
      			;;
      *)		dirs="$dirs $arg";
  			;;
      esac
      shift
      arg=$1
    done
  fi
  
  if [ $help = 1 ]
  then
    display_usage
    exit 0
  fi
  
  if [ $verbose = 1 ]
  then
    cdrecord_v="-v"
    mkisofs_v="-v"
    if [ $quiet = 1 ]
    then
      die "$0: --quiet (-q) and --verbose (-v) are incompatible"
    fi
  fi
  
  if [ -z "$dirs" -a -z "$dirfile" ]
  then
    error "$0: no paths specified."
    usage_die
  fi
  if [ -z "$logfile" ]
  then
    logfile=$logs/cdbackup$date.log		# name of log file to write
  fi
  
  if [ ! -z "$dirfile" ]
  then
    if [ -r "$dirfile" ]
    then
      dirs="$dirs `cat $dirfile`"
    else
      error "$0: ${dirfile}: no such file or file unreadable"
      usage_die
    fi
  fi
}

######################################################################

process_args "$@"

# remove any old backup file
$really rm -f $isofs

qecho "Making ISO-9660 filesystem (with Rock Ridge extensions) on $isofs."

# -R = Rock Ridge extensions
# -T = translation table
# -A = set application ID
if [ "$quiet" = "1" ]
then
$really mkisofs -R -T \
  -A "$host $date backup" \
  $excludes \
  -o $isofs \
  $dirs > /dev/null 2>&1
else
$really mkisofs -R -T \
  $mkisofs_v \
  -A "$host $date backup" \
  $excludes \
  -o $isofs \
  $dirs
fi

if [ "$yes" != "1" ]
then
  echo "Insert CD-R into CD recorder, quiet system, and press Return."
  qecho "  (Warning: this may take a *long* time!)"
  read junk
fi

$really cdrecord \
  $cdrecord_blank \
  $cdrecord_v \
  speed=$speed \
  dev=$dev \
  -data $isofs

qecho "CD written; generating log file in $logfile"

# CD-R might need a moment to be mountable?
$really sleep 5

$really mount -t iso9660 -o ro /dev/scd0 /mnt
$really cd /mnt
if [ -z "$really" ]
then
  find . -ls > $logfile
else
  echo "find . -ls > $logfile"
fi
$really cd /
$really umount /mnt

qecho "Backup log is in $logfile"