Stop command when key no longer being pressed in Bash - bash

Question

Thought this would have been more obvious, but I need to run a command whilst a key is being pressed, and stop the command (SIGINT) when it's no longer pressed.
For example:
#!/bin/bash
while [ F5 is being pressed ] ; do
arecord -f cd -t wav
done

Answer 1

Forwarding from PlayShell's keys.sh you can have:
#!/bin/bash
shopt -s extglob
KEYS_F5=$'\e[[E'
KEYS_XTERM_F5=$'\e[15~'
function keys_readonce {
__V0='' __V1=''
local A K
local -a KEY=() S=() T=()
for A; do
case "$A" in
+([[:digit:]]))
T=(-t "$A")
;;
-q|--quiet)
S=(-s)
;;
*)
echo "Invalid argument: $A"
exit 1
;;
esac
done
local IFS=''
if read -rn 1 -d '' "${T[#]}" "${S[#]}" K; then
KEY[0]=$K
if [[ $K == $'\e' ]]; then
if [[ BASH_VERSINFO -ge 4 ]]; then
T=(-t 0.05)
else
T=(-t 1)
fi
if read -rn 1 -d '' "${T[#]}" "${S[#]}" K; then
case "$K" in
\[)
KEY[1]=$K
local -i I=2
while
read -rn 1 -d '' "${T[#]}" "${S[#]}" "KEY[$I]" && \
[[ ${KEY[I]} != [[:upper:]~] ]]
do
(( ++I ))
done
;;
O)
KEY[1]=$K
read -rn 1 -d '' "${T[#]}" 'KEY[2]'
;;
[[:print:]]|$'\t'|$'\e')
KEY[1]=$K
;;
*)
__V1=$K
;;
esac
fi
fi
__V0="${KEY[*]}"
return 0
fi
return 1
}
while keys_readonce 5 && [[ $__V0 == "$KEYS_F5" || $__V0 == "$KEYS_XTERM_F5" ]]; do ## 5 secs. timeout is optional
# Do something
:
done