Bash Scripting Sound Audio Beep pcspkr

bashbeep.sh

#!/bin/bash
# 255                              mysmps                      SIMPLE SAWTOOTH SOUND
#                         <----------------------->            \/\/\/\/\/\/\/\/\/\/\
#                         .                       .            A beep for bash shell
#                         |               mypeak  |            for machines without
# \                       |                       /\           pc speaker beep \007.
#   \                     |                     /    \ 
#     \                   |                   /        \       It requires alsa and
#       \                 |                 /            \     'play' via alsautils.
#         \               |               /                \
#           \             |             /                    \
#126 ---------------------|---------------------------------------------------------
#               \         |          /                          \
#                 \       |        /                              \                /
#                   \     |      /                                  \            /
#                     \   |    /       When invoking mynote()         \        /
#                       \    /         mysmps * myslop may not          \    /
#                         \/           exceed 255.  We entrust            \/
#                   mytrou             you to use mynote with
#                                      care & respect for math.
#                            
# 1
mynote() {
	mysmps=$1               # number of samples before wave reverses (1/2 cycle)
	myslop=$2                 # vertical step increment of the slope (steepness)
	mycycl=$3                     # number of times to repeat (duration of beep)
	mypeak=$((126 + mysmps))
	mytrou=$((126 - mysmps))
	for ((i = 1; i <= mycycl; i++)); do                     # outer loop: cycles
		for ((j = mypeak; j >= mytrou; j -= myslop)); do     # falling slope
			printf -v hex %x "$j"                          # hexen magic
			printf "\x$hex"
		done
		for ((j = mytrou; j <= mypeak; j += myslop)); do      # rising slope
			printf -v hex %x "$j"
			printf "\x$hex"
		done
	done
}
bignote=$(mynote 24 4 300)
#echo -ne "$bignote" > /tmp/beep.raw         # Save for visual inspection or
#od -tx1 /tmp/beep.raw                       # further adventures in beeping.
for i in {1..50}; do                         # Repeat for beeping glory.
	for i in {1..3}; do
		echo -ne "$bignote" | aplay  -t raw -q -f U8 --channels=2 --rate=48000
		sleep 0.7s
	done
	sleep 3s
done