#! /usr/bin/env bash

# Sleeps until a process id no longer exists.

if [[ $# -ne 2 ]]; then
  >&2 echo "usage: $0 <pid to wait for> <max secs to wait>"
  exit 1
fi

wait_pid=$1
max_wait=$2
wait_count=0

while kill -0 $wait_pid &> /dev/null; do
  let "wait_count += 1"

  if [[ $wait_count -ge $max_wait ]]; then
    >&2 echo "error: process $wait_pid still exists after $max_wait seconds"
    exit 1
  fi

  sleep 1
done