Get Wi-Fi interface device names

Question

Similar to a previous question about finding network device names, I would like to get a (reliable) list of device names but just for Wi-Fi devices. So that it looks like the following depending on your naming structure:

wlan0
wlan1

or

wlp5s0
wlp5s1

Answer 1

On linux you have iw (show/manipulate wireless devices and their configuration) and when used with the dev command:

Commands:
    dev
        List all network interfaces for wireless hardware.

that is

iw dev

you'll get something like:

phy#0
    Interface wlan0
        ifindex 3
        wdev 0x1
        addr 00:12:32:e4:18:24
        type managed
phy#1
    Interface wlan1
        ifindex 4
        wdev 0x2
        addr 00:12:22:c6:b2:0a
        type managed

If you want to extract only interfaces names you can always process the output e.g.

iw dev | awk '$1=="Interface"{print $2}'

just keep in mind the help page clearly states:

Do NOT screenscrape this tool, we don't consider its output stable.

Answer 2

On Ubuntu at least, there is the /proc/net/wireless file that contains details about the Wi-Fi interfaces. Which outputs for me:

$ cat /proc/net/wireless
Inter-| sta-|   Quality        |   Discarded packets               | Missed | WE
 face | tus | link level noise |  nwid  crypt   frag  retry   misc | beacon | 22
wlp5s0: 0000   36.  -74.  -256        0      0      0     16  33004        0

It's a little messy but the device name is in there.

To get just the interface name:

cat /proc/net/wireless | perl -ne '/(\w+):/ && print $1'

The perl code prints the string of word characters preceding the colon.

Answer 3

If you have sysfs mounted at /sys then the following commands work:

# find /sys/class/net -follow -maxdepth 2 -name wireless | cut -d / -f 5
wlan0
# find /sys/class/net -follow -maxdepth 2 -name phy80211 | cut -d / -f 5
wlan0

Or, without find:

for dev in `ls /sys/class/net`; do
  if [ -d "/sys/class/net/$dev/wireless" ]; then echo $dev; fi;
done

The first finds all devices in /sys/class/net with a wireless directory (which may be more than just WiFi devices) and the second finds devices that are 802.11 compatible

Tested on kernel 4.4

Answer 4

Building on Josh's answer, I'll use a shell glob to identify the /sys/class/net directories with a wireless directory inside, and awk to grab the device name:

# find the directories
$ echo /sys/class/net/*/wireless # substitute with phy80211 if desired
/sys/class/net/wlp4s0/wireless
# filter out the "device" part
$ echo /sys/class/net/*/wireless | awk -F'/' '{ print $5 }'
wlp4s0