pa-info only works with bash and coreutils
So this is not very useful on an embedded device without bash.
One (basically untested) suggestion is this:
function cards_get {
ls -d /proc/asound/card[0-9] 2>/dev/null |sed 's#^/proc/asound/card##'
}
The busybox ps
does not know about "aux" arguments, and the ash shell does not work with arrays.