Get connected Wi-Fi network signal strength with nmcli

Question

I'm able to get the signal strength of all Wi-Fi networks with the following command:

$ nmcli -t -f SIGNAL device wifi list
$ 77
  67
  60
  59
  55
  45
  44
  39
  39
  37

I would like to reduce this list only to the current Wi-Fi on which I'm connected. I've been through the man page but can't find the necessary flag.

One solution would be to use sed or awk, but I would like to avoid piping.

Should I use nmcli device wifi instead of parsing directly for the SIGNAL column?

Or use the newer `iw scan` etc. instead of the older `iwconfig`. — dirkt, Nov 22 '18 at 10:15

GAD3R · Accepted Answer · 2022-02-04T12:25:16.590

6

nmcli --version
nmcli tool, version 1.6.2

To get the SIGNAL of the AP on which you are connected, use:

nmcli dev wifi list | awk '/\*/{if (NR!=1) {print $7}}'

The second * mark in nmcli dev wifi list is set to identify the SSID on which your are connected.

nmcli --version
nmcli tool, version 1.22.10

use:

nmcli dev wifi list | awk '/\*/{if (NR!=1) {print $6}}'

edited Feb 04 '22 at 12:25

answered Nov 22 '18 at 10:25

GAD3R

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It works for me if I use `print $6` instead of `print $7`. – Grégoire Borel Nov 22 '18 at 10:28
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@GrégoireBorel Great! it depend on `nmcli` version. – GAD3R Nov 22 '18 at 10:30
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Debugging failing scripts if it depends on the nmcli version will be fun... – dirkt Nov 22 '18 at 11:27
This will fail if you connect to SSIDs with varying numbers of spaces in them – apnorton Dec 05 '20 at 22:35

score 6 · Answer 2 · answered Dec 05 '20 at 22:47

The trick here is to use the -f parameter of nmcli to specify what fields you want in your script. If you care about the SSID, use the SSID field; if you care about which one you're connected to, use the IN-USE field:

$ nmcli -f IN-USE,SIGNAL device wifi
*  SIGNAL 
   90
*  73     
   40
$ nmcli -f IN-USE,SIGNAL,SSID device wifi
*  SIGNAL  SSID               
   90      wifiWithoutSpaces
*  73      Some Wifi With Spaces
   40      Wifi With a * in its SSID

The advantage of ordering the fields in this way is that selecting the signal is a fixed number of column-delimiting characters from the start of the row; we can now use GAD3R's answer without running into column count or nmcli versioning issues:

$ nmcli -f IN-USE,SIGNAL,SSID device wifi | awk '/^\*/{if (NR!=1) {print $2}}'
73

telcoM · Answer 3 · 2020-06-06T12:00:48.940

2

If you know the name of the network you're connected to, you could modify your approach like this: (for nmcli 1.14.6, other versions may vary)

nmcli -t -f SSID,SIGNAL dev wifi list | grep "^<network name>:" | cut -d : -f 2

edited Jun 06 '20 at 12:00

answered Nov 22 '18 at 10:06

telcoM

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@telecoM Your command does not work, can you please fix it ? – SebMa Jun 06 '20 at 08:20
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@SebMa I think it used to work that way with Debian 9 in late 2018, but now it's different in Debian 10. Edited. Remember to replace `` with the name of the network. – telcoM Jun 06 '20 at 12:02
@telecoM Now it works, thanks – SebMa Jun 06 '20 at 12:49

score 0 · Answer 4 · edited Dec 29 '21 at 19:30

0

A simple way to see the router in use:

nmcli -f IN-USE,SIGNAL device wifi | grep '*'

edited Dec 29 '21 at 19:30

Jeff Schaller

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answered Dec 29 '21 at 18:12

Pasi

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Get connected Wi-Fi network signal strength with nmcli

4 Answers4