Monitoring WiFi devices from the command line
Programming Snapshot – Go WiFi Monitor
© Lead Image © Sergey Nivens, 123RF.com
To see when clients are joining and leaving the wireless network, Mike Schilli writes a command-line utility that uses an object-relational mapping interface to store metrics in SQLite to later display historical data.
"What I don't know won't hurt me," as the saying goes, but the reverse is true for my wireless network. What are all my household gadgets doing? After all, no newly released device seems to be able to manage without a wireless network connection nowadays. Or are there actually some devices that I don't even know about? This definitely worries me and keeps me tossing and turning in my sleep.
On top of that, I am interested in more than the current situation. Curious by nature, I would like to know how long a device, once discovered, has been operating on the network, when it joined the network, and whether it is permanently active or occasionally lets its assigned IP address lease expire and then picks up a new one later. Let's build a data logger in Go to find out.
To detect active devices on the wireless network, it makes sense to call up the nmap scanner. This hacking tool is included with every good Linux distribution and knocks on the door of all potentially usable IP addresses in a subnet to see if a host responds. On a typical 192.168.0.0/24 subnet of a router for home network use, you can use 255 IP addresses, and nmap scans them with a barrage of probes at lightning speed (Figure 1).
[...]
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Digital Autonomy
• The Answer Was Already on the Shelf
• Changing the Chip Industry: How Public Investment Has Grown Open Silicon
• United Nations Open Source Portal Goes Live
• EU Open Source Strategy Plays Key Role in Tech Sovereignty Package
• France Says “Au Revoir” to Microsoft
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Pine64 Halts Production of Linux Devices
With continued DRAM and eMMC shortages, Pine64 has decided to discontinue production of Linux devices.
-
The Bullet-Proof KDE Software Initiative Is Coming
KDE, Techpaladin, and Kubuntu Focus have announced a new initiative that will provide at least three years of support for KDE Plasma 6.6 LTS and related software.
-
Linux Mint Shares a Possible Kernel Cleanup Solution
For those on Linux Mint who like to keep multiple kernels around but don't want them to take up too much space, you might be getting a new automated tool.
-
CachyOS Gets an Update
CachyOS August 2026 release is now available with the latest version of KDE, some new features, and plenty of improvements.
-
The Linux Kernel Dev Staging Area Now Rejects AI-Generated Patches
Unless a kernel patch is a valid security fix, it will be rejected if it was created using AI.
-
Linux Surpasses Double-Digit Market Share
According to two sources, the Linux operating system has hit a major milestone in market share that naysayers thought would never happen.
-
AI Helped Develop a Linux Exploit
A use-after-free race exploit was discovered and exploited on CentOS Stream 9.
-
Yet Another Linux Kernel Vulnerability Discovered
Affecting millions of systems, a kernel flaw discovered by Qualys could allow users to gain root privileges.
-
Ubuntu 26.10 to Include Ubuntu Certified Hardware Check
If you've ever wondered if your laptop or PC is officially certified to run Ubuntu, that curiosity will soon be met.
-
Substantial Update to IPFire Now Available
The lastest version of IPFire features a fundamental change to how the system handles DNS.