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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
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.
sudo iw dev, because running it as a non-privileged user may return no results.
Dec 3, 2020 at 8:02
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.
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
[ -d "/sys/class/net/$dev/wireless" ] && echo "$dev"
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
ls is bad practice and a common pit fall in bash.
Jan 27, 2021 at 23:51
find solution too; it only finds files that actually exist which solves the awkward * that other solutions here get. I found that I needed a slightly different set of parameters to reduce the amount of noise cause by file system loops. The following works nicely for me, but does spawn an extra subshell for cut and relies on assumptions about indexes: find -H /sys/class/net/* -name wireless | cut -d / -f 5 Furthermore I needed an additional | head -n1 for my particular use-case.
Jan 28, 2021 at 0:15
Universal way (non root) tested on Android 4, Android 7.1 and Android 9 and ArchLinux.
ls /sys/class/ieee80211/*/device/net/
Building on Josh's answer, I'll use a shell glob to identify the /sys/class/net directories with a wireless directory inside, and cut to grab the device name:
# find the directories
$ printf '%s\n' /sys/class/net/*/wireless # substitute with phy80211 if desired
/sys/class/net/wlp4s0/wireless
# filter out the "device" part
$ printf '%s\n' /sys/class/net/*/wireless | cut -d/ -f5
wlp4s0
* if no wireless device exists, instead of an empty result. Instead, try this with only POSIX shell built-ins: printf '%s\n' /sys/class/net/*/wireless | while IFS='/' read -r -a p;do [ -e "/sys/class/net/${p[4]}" ] && echo "${p[4]}";done.
* out: printf '%s\n' /sys/class/net/*/wirelessREMOVETHIS | cut -d / -f 5 | grep -v '*'
Jan 27, 2021 at 22:08
* part though; I really think it depends on what you're doing, what the shell options are, and whether or not your device might have an asterisk in it (shudders)
Jan 27, 2021 at 22:10
Here's a simple and very effective loop that answers the question:
for dev in /sys/class/net/*; do
[ -e "$dev"/wireless ] && echo ${dev##*/}
done
This one picks the first wireless interface and stores it in $iwdev, which was what I needed:
for dev in /sys/class/net/*; do
if [ -e "$dev"/wireless ]; then
iwdev=${dev##*/};
break;
fi
done
It's a rewrite of Josh's answer which I found nice and simple. The above approach handles spaces and other oddities in file names. It also doesn't make too many assumptions about file paths being sane and relies on a minimum of slashes and indexing. Finally it uses built-in parameter expansion for extracting the base device name instead of spawning a subshell for cut or awk.
Use find command tool
This finds the actual file that contains the name, it should work in most cases and it's really a short command:
# For WiFi
find /sys/class/net/ -name "wlp*" -exec basename \{} \;
# For Ethernet
find /sys/class/net/ -name "enp*" -exec basename \{} \;
Here's the little bash function I wrote to cover more exceptions :
lswifiInterfaces () {
set -o pipefail # I use this to preserve the return code of the first command in the pipe
if \ls /sys/class/ieee80211/*/device/net 2> /dev/null; then
:
elif \ls -d /sys/class/net/*/wireless 2> /dev/null | awk -F/ '{print$5}'; then
:
fi
set +o pipefail
}
