Alternative sleep function

#!/usr/bin/env bash

set -u

declare nmi

# Functions

snore()

{

    local IFS

    [[ -n "${_snore_fd:-}" ]] || exec {_snore_fd}<> <(:)

    read ${1:+-t "$1"} -u $_snore_fd || :

}

function checkNMI {

  nmi=$(awk '/NMI/ {for (i=2; i<=NF; i++) if ($i ~ /^[0-9]+$/) {sum+=$i}} END {print sum}' /proc/interrupts)

  local nmi=$(awk '/NMI/ {for (i=2; i<=NF; i++) if ($i ~ /^[0-9]+$/) {sum+=$i}} END {print sum}' /proc/interrupts)

  if [ "$nmi" != "" ] && [ "$nmi" -ne "0" ]; then

}

# Setup serialport

chmod 666 /dev/ttyS0

checkNMI

# Install packages 

first_run=false

for filename in /usr/local/packages/*.spk; do

fi

# Display message in docker log output

echo "-------------------------------------------" > /dev/ttyS0

echo " You can now login to DSM at port 5000     " > /dev/ttyS0

echo "-------------------------------------------" > /dev/ttyS0

# Wait for NMI interrupt as a shutdown signal

while true; do

  checkNMI

  sleep 2

  snore 2

done