misc/scripts/beep-charlie

#!/bin/sh

lock=/tmp/.beep-lock
test -f $lock && exit 1 || touch $lock
head -c 8 /dev/urandom | \
   hexdump -v -e '/1 "%u\n"' | \
   awk '{ split("0,3,5,6,7,10,12",a,","); \
   for (i = 0; i < 1; i+= 0.00012) \
   printf("%08X\n", 60*sin(450*exp((a[$1 % 8]/12)*log(2))*i)) }' | \
   xxd -r -p | \
   aplay -c 1 -f S32_LE -r 48000 -D plug:default
rm -f $lock