As per this: https://linux.die.net/man/8/iwlist I understand that scanning of WiFi Networks requires root access. If you are a regular user than you can only see the Wifi Network you are connected with. Lets go into my problem...

As a regular user when I use this command in terminal:

iwlist wlan0 scan|grep "Frequency\|Quality\|ESSID"

Then my output is this:

Frequency:2.417 GHz (Channel 2)
Quality=67/70  Signal level=-43 dBm  

That is the network I am currently connected to (My-WiFi)

When I run this command in terminal as sudo:

sudo iwlist wlan0 scan|grep "Frequency\|Quality\|ESSID"

Then my output is this:

Frequency:2.417 GHz (Channel 2)
Quality=69/70  Signal level=-41 dBm  
Frequency:2.412 GHz (Channel 1)
Quality=43/70  Signal level=-67 dBm  
Frequency:2.412 GHz (Channel 1)
Quality=61/70  Signal level=-49 dBm  
Frequency:2.427 GHz (Channel 4)
Quality=36/70  Signal level=-74 dBm  

My problem is that I need to scan the WiFi networks without a normal user having sudo access.

How can I change permissions to run iwlist wlan0 scan|grep "Frequency\|Quality\|ESSID" to show the sudo output, but without using sudo or having root access?

  • Go it working. The test user is bob so I used the command sudo visudo and at the end of the file I put in this line bob ALL=NOPASSWD:/sbin/iwlist Now when I am on the user bob I can use sudo iwlist wlan0 scan|grep "Frequency\|Quality\|ESSID" without the system asking me for password. Other sudo commands are still protected.
    – Joe Elia
    Aug 7, 2019 at 23:58
  • If you solved it, then enter your answer as an answer rather than a comment.
    – Brick
    Aug 8, 2019 at 2:16

1 Answer 1


Your "solution" is the sledgehammer approach.

Editing the sudoers file is not recommended. If you really want to do so it is safer to make a new entry in /etc/sudoers.d (which is used to give user pi passwordless sudo)

If you want all users to be able to run a command setting suid permission is more normal.

sudo chmod a+s /sbin/iwlist
  • This is the correct answer because unlike /etc/sudoers (file that opens with sudo visudo command), the contents of /etc/sudoers.d survives system upgrades, so it's preferable to create a file there than to modify /etc/sudoers.
    – Joe Elia
    Aug 8, 2019 at 4:45

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