dvdrip-upload: Replace the signalling protocol with, err, signals.

[dvdrip] / dvdrip-upload

#! /bin/bash -e

prog=${0##*/}
tmp=${DVDRIP_TMPDIR-${HOME?}/tmp/dvdrip}
archive=${DVDRIP_ARCHIVE-jem.distorted.org.uk:/mnt/dvd/archive}
kill=nil listen=nil verbose=nil bogus=nil opts=; unset dir sub n label
usage () {
  cat <<EOF
usage: $prog [-klv]
EOF
}
while getopts "ha:klv" opt; do
  case $opt in
    h) usage; exit 0 ;;
    a) archive=$OPTARG ;;
    k) kill=t ;;
    l) listen=t; opts=${opts}l ;;
    v) verbose=t; opts=${opts}v ;;
    *) bogus=t ;;
  esac
done
shift $(( $OPTIND - 1 ))
case $# in
  0) ;;
  *) bogus=t ;;
esac
case $bogus in t) usage >&2; exit 2 ;; esac
case $verbose in t) set -x ;; esac

notify () {
  colour=$1 message=$2
  echo "$(tput bold; tput setaf $colour)$message$(tput sgr0; tput op)"
}
fail () { notify 1 "!!! $*"; exit 2; }
warn () { notify 5 "??? $*"; }
info () { notify 6 "--- $*"; }
run_setrc () {
  notify 2 "+++ $*";
  set +e; nice "$@"; rc=$?; set -e
}
run () { run_setrc "$@"; case $rc in 0) ;; *) fail "$1: exit $rc" ;; esac; }

case $archive in
  *:*) archhost=${archive%%:*} archpath=${archive#*:} ;;
  *) unset archhost; archpath=$archive ;;
esac

archdo () {
  op=$1; shift
  case ${archhost+t} in
    t)
      qq=
      for a in "$@"; do
	qq="${qq:+$qq }'${a//\'/"'\\''"}'" #" # emacs is confused
      done
      "$op" ssh "$archhost" "$qq"
      ;;
    *)
      "$op" "$@"
      ;;
  esac
}
archrun () { archdo run "$@"; }

check () {
  while :; do
    any=nil
    for i in "$tmp"/*; do
      if [ -f "$i/dest" ]; then
	read dest <"$i/dest"; any=t
	mv "$i/dest" "$i/dest.seen"
	(info "copy $i/iso -> $dest"
	 case $dest in
	   */*) dir=${dest%/*} ;;
	   *) dir= ;;
	 esac
	 archrun mkdir -p "$archpath${dir:+/$dir}"
	 run rsync -svPSW "$i/iso" "$archive/$dest"
	 run rm -rf "$i") || :
      fi
    done
    case $any in nil) break ;; esac
  done
}

try_kick_daemon () {
  sig=$1

  if [ -f "$tmp/upload.pid" ]; then
    daemon=$(cat "$tmp/upload.pid")
    case $daemon in
      "" | *[!0-9]*) ;;
      *) if kill -$sig $daemon >/dev/null 2>&1; then return 0; fi ;;
    esac
  fi
  return 1
}

try_kill () {
  victim=$1

  case $victim in
    nil) ;;
    *) kill $victim >/dev/null 2>&1 || : ;;
  esac
}

case $kill,$listen in
  t,t)
    fail "inconsistent options \`-k' and \`-l'"
    ;;
  t,nil)
    if ! try_kick_daemon TERM; then fail "failed to kill listener"; fi
    ;;
  nil,t)
    if try_kick_daemon 0; then fail "daemon already running (pid $daemon)"; fi
    trap 'try_kill $sleepy; rm -f "$tmp/upload.pid"' EXIT
    trap 'info "quitting on user request"; exit 0' INT TERM
    trap 'try_kill $sleepy' HUP
    echo $$ >"$tmp/upload.pid.new"
    mv "$tmp/upload.pid.new" "$tmp/upload.pid"
    while :; do
      sleep 3600& sleepy=$!
      check
      wait $sleepy || :; sleepy=nil
    done
    ;;
  nil,nil)
    if ! try_kick_daemon HUP; then check; fi
    ;;
esac