Restart multiple shell commands synchronously (example)

runsync.sh

#!/bin/bash

# Run two video players more or less in sync
# assuming they start playing immediately and
# exit when done playing

while true
do
  # Start all players in the background
  
  # VLC settings: full screen, select the right display, quit after playback
  /Applications/VLC.app/Contents/MacOS/VLC -f movie1.mov &
  
  # Use AppleScript to run quicktime full screen
  osascript play.scpt &

  echo "Waiting for player jobs..."  
  jobsOutput="not empty"
  while [[ -n "$jobsOutput" ]]
  do
    jobsOutput=$(jobs | grep -v ' Done')
    sleep 1
  done
  echo "Done waiting."
  
done