Respawn node application on error. Using for test perpouses

spawn.sh

# Default respawn delay value
delay=5
# Default environment value
env="development"


#Show help
if [[ "$@" = "--help" ||  "$@" = "-h" ]]; then
  cat <<EOF
Usage: bash spawn.sh [FILE...] [OPTIONS...]
Respawn application on failure

    -d  delay in seconds
    -e  environment: production or development
EOF
  exit;
fi

#Getting filename
app=$1
args="${@:2}"

# Parse options
while getopts ":e:d:" optname $args; do
  value="$OPTARG"
  case "$optname" in
    "h")
      echo "Usage is..."
      exit;
    ;;
    "d")
      delay="$value"
    ;;
    "e")
      env="$value"
    ;;
    ?) printf "Unknown option\n"
    ;;
    *) printf "Error while parsing options\n"
    ;;
  esac
done

if [ "$delay" -lt 1 ]; then
  delay=1
fi

export NODE_ENV="$env"
while [ true ]; do
  #clear screen
  reset
  
  #run node
  node $app $env &
  
  # if node succesfully exit stop respawning
  if wait "$!"; then
    
    printf "\n\nApplication exits\n"
    exit 0;
    
  else
  
    printf "\n\nrespawn in"
    
    count="$delay"
    # Countdown
    while [ $count -gt 0 ]; do
      printf " "$count
      let count=count-1
      sleep 1
    done
    
  fi
done;