readall () {
  read all
  while read line; do
    all="$all\n$line"
  done

  echo -e $all
}

waitpid () {
  pid=$1
  while true; do
    kill -0 $pid &> /dev/null
    if [ $? -ne 0 ]; then
      return
    fi

    sleep 60
  done
}

emailwhendone () {
  # There are four ways to run this:
  # $ emailwhendone PID
  # This traces a PID and emails you when it is no longer found in the list
  # of active processes.
  #
  # $ command && emailwhendone
  # Only send an email when command is successful.
  #
  # $ command ; emailwhendone
  # Send an email even if command fails
  #
  # $ command | emailwhendone
  # Send an email where the message body is the last 100 lines of output from
  # command.
  if [ $# -eq 1 ]; then
    echo "tracing pid $1"
    name=`ps aux | grep --color=none $1 | grep --color=none -v grep`
    waitpid $1
    t=`date "+%D @ %T"`
    echo $name | mail -s "[Job Status] Process $1 on `hostname` has finished - $t" YOUREMAIL
  else
    t=`date "+%D @ %T"`
    # If not reading from STDIN, send "nt" as message body, otherwise
    # send the last 100 lines of output from previous command.
    if test -t 0; then
      echo "nt" | mail -s "[Job Status] Process on `hostname` has finished - $t" YOUREMAIL
    else
      readall | tail -n 100 | mail -s "[Job Status] Process on `hostname` has finished - $t" YOUREMAIL
    fi
  fi
}