OSX Bash script that beeps a pure sinewave, variable by number of beeps, delay and volume

beep.sh

#!/usr/bin/env bash
#shellcheck disable=SC2034

# beep
# *********************************************************
# Generate a beep shell command for OSX 10.7.5+
# Original idea (C)2012, B.Walker, G0LCU.
# Now issued as Public Domain, CC0. You may do with it as you please.

repeat=${1:-1}
volume=${2:-.05}
delay=${3:-.3}

function usage {
  echo "Usage: $(basename $0) [OPTION|OPTION2|...] [repeat] [volume] [delay]
Build and test artifacts in this repository

EXAMPLE

# Beep 3 times, volume 0.05, with a delay of 0.1 seconds between beeps,

  $(basename $0) -d 0.5 -r 3 -v 0.01

# or

  $(basename $0) 3 0.05 0.1

OPTIONS
  -d    Delay between beeps in seconds
  -h    Help information (this text)
  -r    Repeat beeps n times, eg
        $(basename $0) -r 5
  -v    Volume (range 0.01 ... 1)
"
}

OPTIONS=':d:hr:v:'
while getopts $OPTIONS option
do
    case $option in
        d  )    delay=$OPTARG;;
        h  )    usage
                exit;;
        r  )    repeat=$OPTARG;;
        v  )    volume=$OPTARG
                [[ $volume -gt 1 ]] && volume=1
                ;;
        *  )    echo "Unkown option: ${OPTARG}"
                usage
                exit 1;;
    esac
done
shift $((OPTIND - 1))

true > /tmp/sinewave.wav

printf "\x52\x49\x46\x46\x64\x1F\x00\x00\x57\x41\x56\x45\x66\x6D\x74\x20\x10\x00\x00\x00\x01\x00\x01\x00\x40\x1F\x00\x00\x40\x1F\x00\x00\x01\x00\x08\x00\x64\x61\x74\x61\x40\x1F\x00\x00" >> /tmp/sinewave.wav

for i in {0..500}
do
    printf "\x80\x26\x00\x26\x7F\xD9\xFF\xD9" >> /tmp/sinewave.wav
done

for j in $(seq 1 $repeat)
do

  # The line below uses various Linux flavours, "aplay"...
  # aplay /tmp/sinewave.wav

  # Use the OSX default basic command line audio player, "/usr/bin/afplay".
  afplay -v ${volume} /tmp/sinewave.wav

  # "afinfo" is OSX also...
  # afinfo /tmp/sinewave.wav

  sleep $delay

done

exit 0