[ -z "$ifname" ] && {
devname="$(basename "$device")"
case "$devname" in
+ 'ttyACM'*)
+ devpath="$(readlink -f /sys/class/tty/$devname/device)"
+ ifpath="$devpath/../*/net"
+ ;;
'tty'*)
devpath="$(readlink -f /sys/class/tty/$devname/device)"
ifpath="$devpath/../../*/net"