есть строка:
ip link show | sed -n "/^[0-9]/ { s/[[:space:]]//g; s/^[0-9]\+:\([^@-]\+\)\(@.\+\)\?:<.*/\1/; p; }"
lo
eth0
eth1
5:br-lan:<BROADCAST,MULTICAST,UP,LOWER_UP>mtu1500qdiscnoqueuestateUPmodeDEFAULT
wlan0
7:pppoe-vega:<POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP>mtu1492qdiscpfifo_faststateUNKNOWNmodeDEFAULTqlen3
ifb0
ifb1
lo
eth0
eth1
br-lan
wlan0
pppoe-vega
ifb0
ifb1