sleep-in-background.sh

#!/usr/bin/env zsh
set -e
term="$1"
echo $term
loop=1
asleep=.95
awake="`echo "$loop - $asleep" | bc`"
echo "asleep: $asleep, awake: $awake"

trap cleanup INT

function cleanup() {
  function f () { echo "\tExiting: "$1}
  if [ -n "$lastKnownPid" ]; then
    f "continuing \$lastKnownPid ($lastKnownPid)"
    kill -SIGCONT $lastKnownPid
  else
    f "no \$lastKnownPid"
  fi
}

function log () {
  if [[ $1 -lt 2 ]]; then
    echo $2
  fi
}

while true; do
  if [ -n "$lastKnownPid" ]; then
    kill -SIGCONT $lastKnownPid
  fi
  sleep $awake
  {
    pid=$(xdotool getwindowfocus getwindowpid)
    cmdline="$(cat "/proc/$pid/cmdline")"

    pCwd="$(readlink "/proc/$pid/cwd")"

    # TODO use $cmdline as matchbase instead
    # TODO or use both
    # matchbase=$cmdline
    matchbase="$pCwd $cmdline"
    if [ -e "/proc/$lastKnownPid/" ]; then
      # noop
    else
      lastKnownPid=''
      echo 'App runs no more, resetting $lastKnownPid'
    fi
    if (echo "$matchbase" | grep -q $term); then
      log 2 "match ($pid): in $matchbase"
      lastKnownPid=$pid
      # kill -SIGCONT $pid
    else
      log 2 "no match ($lastKnownPid): $matchbase"
      if [ -n "$lastKnownPid" ]; then
        kill -SIGSTOP $lastKnownPid
      fi
    fi
  } || {
    echo 'An error happened. Continuing'
  }
  sleep $asleep
done

cleanup