Answer
The iw tool can be used to read the status of the device:
# iw dev
phy#0 Unnamed/non-netdev interface wdev 0x2 addr 7e:4a:78:cc:85:77 type P2P-device txpower 31.00 dBm Interface wlan0 ifindex 7 wdev 0x1 addr aa:bb:cc:07:0c:b1 ssid testAP type AP channel 11 (2462 MHz), width: 20 MHz, center1: 2462 MHz txpower 31.00 dBm Managed/client mode link information:# iw wlan0 link
Connected to aa:bb:cc:12:34:56 (on wlan0) SSID: testAP freq: 2462 RX: 364 bytes (2 packets) TX: 3782 bytes (22 packets) signal: -31 dBm tx bitrate: 2.0 MBit/s bss flags: short-slot-time dtim period: 2 beacon int: 200 AP mode to read connected client information:# iw wlan0 station dump
Station aa:bb:cc:8b:6c:fe (on wlan0) inactive time: 3000 ms rx bytes: 6479 rx packets: 37 tx bytes: 9706 tx packets: 66 tx failed: 0 signal: -44 [-44] dBm tx bitrate: 1.0 MBit/s rx bitrate: 65.0 MBit/s authorized: yes authenticated: yes associated: yes WMM/WME: yes TDLS peer: no DTIM period: 2 beacon interval:100 short slot time:yes connected time: 20 seconds