Поиск wifi сети linux

How can I get a list of available wireless networks on Linux?

I would like to get a list of the wireless networks available. Ideally this would be via some C call, but I don’t mind if I have to kludge it with a system call. Even better if the required C call or program doesn’t require some exotic 3rd party package. The internet seems to suggest I use sudo iwlist scan which does seem to do the trick from the command line, but I’d rather not require root permissions. I only want to see the basics, not change anything.

You do not need to be root to run iwlist, but it will only report the cached values from the last periodic scan. To force a new scan you do need to be root.

3 Answers 3

It’s pretty easy to do a scan in the command line. The man pages are your friend here (check out iwconfig and iwlist). But using the C interface is a little more difficult so I’ll focus on that.

First of all, as other people have mentioned, definitely download out the wireless tools source code. All the documentation for the programming interface is in the .c files. As far as I can tell, there is no web documentation for the api. However, the source code is pretty easy to read through. You pretty much only need iwlib.h and iwlib.c for this question.

While you can use iw_set_ext and iw_get_ext , the libiw implements a basic scanning function iw_scan , from which you can extract most of the information that you need.

Here is a simple program to get the ESSID for all available wireless networks. Compile with -liw and run with sudo .

#include #include #include int main(void) < wireless_scan_head head; wireless_scan *result; iwrange range; int sock; /* Open socket to kernel */ sock = iw_sockets_open(); /* Get some metadata to use for scanning */ if (iw_get_range_info(sock, "wlan0", &range) < 0) < printf("Error during iw_get_range_info. Aborting.\n"); exit(2); >/* Perform the scan */ if (iw_scan(sock, "wlan0", range.we_version_compiled, &head) < 0) < printf("Error during iw_scan. Aborting.\n"); exit(2); >/* Traverse the results */ result = head.result; while (NULL != result) < printf("%s\n", result->b.essid); result = result->next; > exit(0); > 

DISCLAIMER: This is just a demonstration program. It’s possible for some results to not have an essid. In addition, this assumes your wireless interface is «wlan0». You get the idea.

Read the iwlib source code!

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Scan for wifi Network

There are a multitude of fine, graphical wireless network configuration programs available to the Ubuntu community. However, there may come a day when you need to acquire a wireless connection from an unknown network on a strange network card from the recovery console. Or perhaps you just want to know how to connect to your home network from the command line. Either way, this HOWTO is for you.

This guide assumes that the drivers for your network card are properly set up. Otherwise, it would be too complicated to cover all vendors and chipsets.

Find Network Interface Card

Figure out the name of the interface for your wireless card

The interface name of cards for different vendors may be different, which is why this step is needed:

This will list the interface names for all NICs on your computer. It will probably include eth0 (hardwired NIC), lo (loopback interface for the localhost), and something for your wireless card (like wifi0, or wlan0).

For these steps let’s call whatever name you find for your wireless NIC [wifi interface].

If you have multiple wireless cards, all of them will be listed. To be sure that the interface that you select is a wireless interface, you can check that its directory contains a «wireless» folder:

cd /sys/class/net/[wifi interface]/wireless/

Release network connections

Just to be sure it’s not being used, bring your interface down, release your DHCP connection and then put it back up:

sudo ip link set dev [wifi interface] down sudo dhclient -r [wifi interface] sudo ip link set dev [wifi interface] up

Many of these commands require superuser priviledges (i.e. root access), so the sudo command precedes them. Of course, you could always use «sudo -s» or some other method to login to a shell as the root account, but why complicate matters?

Scan

sudo iwlist [wifi interface] scan

Note: In tests this command only worked with Atheros cards.

This should return results that look something like this:

wlan0 Scan completed : Cell 01 - Address: 00:04:E2:D0:D1:96 ESSID:"SMC" Mode:Master Channel:6 Frequency:2.437 GHz Quality=78/100 Signal level=-56 dBm Noise level=-127 dBm Encryption key:off Bit Rates:1 Mb/s; 2 Mb/s; 5.5 Mb/s; 11 Mb/s; 6 Mb/s 9 Mb/s; 12 Mb/s; 18 Mb/s; 24 Mb/s; 36 Mb/s 48 Mb/s; 54 Mb/s Extra:tsf=00000039cdb32ac3

The ESSID, Frequency and Address are the most important labels here (quality may also factor into your decision, too. higher is better).

Setup Network Interface Card

Set the wireless NIC so that it will connect to the found wireless network:

sudo iwconfig [wifi interface] ap [whatever you found for the MAC address] sudo iwconfig [wifi interface] essid [whatever you found for essid] sudo iwconfig [wifi interface] freq [whatever you found for frequency]G

Note the «G» after the frequency, to denote «GHz».

Acquire Network Address

Acquire a DHCP address from your wireless router:

sudo dhclient [wifi interface]

Okay. assuming that your DHCP address was acquired properly, you should have a internet connection all set up. Now, this is probably too complicated of a process to do by hand, but there are a number of ways to automate it. That’s outside the scope of this tutorial!

Compatible Chipsets

It has become apparent that not all wireless interface cards work with the scan command. Can you add your results to the table below.

Command to find the manufacture and model of your pci card is:

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Как отобразить доступные WiFi сети, их каналы, уровень сигнала и т.д. из командной строки

В этой статье объясняется, как использовать командную строку для просмотра доступных сетей Wi-Fi в Linux, списка их каналов, качества связи, безопасности, уровня сигнала и многого другого.
Это полезно для сканирования доступных сетей Wi-Fi, чтобы быстро определить уровень их сигнала, просмотра их каналов, чтобы увидеть, какой канал WiFi используется для уменьшения помех, и так далее и тому подобное.
Существует несколько методов/инструментов для сканирования доступных сетей Wi-Fi и перечисления их сведений, но в этой статье я перечисляю только 2 метода, которые просты в использовании и предоставляют достаточно информации для выполнения задачи.

Вариант №1: Сканируем и выводим список доступных WiFi-сетей с помощью nmcli

нмкли, Инструмент командной строки для управления состоянием сети и составления отчетов, может сканировать и составлять список доступных сетей WiFi, независимо от того, подключен ли WiFi к сети. Он уже должен быть установлен в вашем дистрибутиве Linux, нет необходимости указывать имя интерфейса, и он по умолчанию работает без привилегий суперпользователя (sudo), или, по крайней мере, так в моих тестах на Fedora и Ubuntu Situation. Используйте следующие команды для отображения доступных беспроводных сетей SSID, режимов, каналов, скоростей передачи, уровней сигнала, полос и безопасности:

Я видел, как некоторые пользователи говорят, что им нужно запускать nmcli с помощью sudo, чтобы показать доступные беспроводные сети, но это не тот случай, когда они пытаются использовать Fedora 31 и 30, Ubuntu 19.10 или 18.04. Однако, если nmcli ничего не отображает, попробуйте запустить его с помощью sudo:

Чтобы заставить nmcli отображать дополнительную информацию о сканируемой сети Wi-Fi, включая SSID-HEX, BSSID, частоту и т. д., запустите его следующим образом:

Скриншоты:

Это отобразит отсканированные данные WiFi в таблице. Если вы хотите переключиться на многострочный вид, чтобы вам не нужно было увеличивать ширину окна терминала, чтобы увидеть все детали, используйте -m multiline , так:

nmcli -m multiline -f ALL dev wifi

Чтобы использовать в скрипте, используйте краткий ( -t ) метод вывода:

Если вы хотите заставить nmcli повторно сканировать доступные сети Wi-Fi, используйте rescan Параметры:

Вариант 2. Используйте wavemon, чтобы получить список доступных сетей Wi-Fi.

ВейвмонТерминальный пользовательский интерфейс (TUI), использующий ncurses для мониторинга уровня беспроводного сигнала и шума, статистики пакетов, конфигурации устройства и параметров сети. Если вы не используете NetworkManager или просто предпочитаете nmcli, используйте его вместо nmcli.
Используйте его, чтобы получить список доступных точек доступа Wi-Fi, независимо от того, подключены ли они к сети Wi-Fi или нет. Инструмент требует прав суперпользователя (например, для запуска с помощью sudo) для сканирования доступных сетей Wi-Fi по умолчанию.
Wavemon может отображать следующую информацию о доступных (отсканированных) сетях Wi-Fi: SSID, BSSID (mac-адрес точки доступа), качество сигнала, мощность сигнала, канал и частоту WiFi. Wavemon не устанавливается по умолчанию, но многие дистрибутивы Linux доступны в следующих репозиториях. Установите следующим образом:

• Debian, Ubuntu, Linux Mint, Pop! _OS, Elementary OS и другие дистрибутивы Linux на базе Debian или Ubuntu:

sudo zypper install wavemon

Чтобы выполнить поиск доступных сетей Wi-Fi, нажмите F3 Перейдите на вкладку «Сканирование». Ищете продвинутый WiFi-сканер с большим количеством функций? Попробуйте Kismet, инструмент командной строки, который получил веб-интерфейс в апреле 2019 года.

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How can I display the list of available Wi-Fi networks?

My Ubuntu laptop’s Wi-Fi works fine on various Wi-Fi networks. But the list of available networks accessed from the toolbar icon of nm-applet no longer appears. I just see the known networks. The list of hidden networks also doesn’t show any new networks. sudo iwlist scan likewise only shows known networks. How do I get a list of all available networks so I can connect to one? I am using Xubuntu 14.04.

Does terminal command nmcli dev wifi list give anything additional to what’s shown by the GUI applet?

Also worth noting that sudo iwlist scan shows more available networks than iwlist scan (without sudo ) — so this question by itself is helpful. But perhaps it should be renamed to «How can I display the list of hidden WiFi networks»?

4 Answers 4

Use the nmcli dev wifi command. It shows transfer rate, signal strength, and security (e.g. WPA) as well:

For more, see nmcli ‘s manual and this for usage examples of nmcli .

Here is the pertaining mnemonic: network manager command line interface device wifi

The BSSID (MAC of remote access point) and other details are not shown by default, but you can show them with the -f option, e.g. nmcli -f SSID,BSSID,DEVICE dev wifi . Use -f ALL to see available fields.

@icc97 — if you only see your current network, run nmcli dev wifi rescan , wait a bit, and then try nmcli dev wifi again.

To scan all networks try using the command sudo iw dev wlan0 scan | grep SSID .

wlan0 should be replaced with real value from ifconfig of from /sys/class/net subfolder name, as stated in answer from @gujarat santana

This works better than nmcli for me because it breaks down and shows non-latin characters, where nmcli just shows a «?»

@EkriirkE well, for a more detailed breakdown on wifi networks in nmcli command you could use -f ALL option, e.g. nmcli -f ALL dev wifi . Although I admit, it’s still not as detailed as iw ‘s information.

@EkriirkE sorry, I probably misread your comment. You stated that it worked better for you since «it breaks down», and I thought you meant «breaking down» as in «showing detailed information». With that said, I am not sure who are «we» ☺ I definitely wanted the technical details on the networks, and the question or the answer don’t seem to limit the question to just SSIDs.

1. Go to /sys/class/net you can see list of directories here.
2. Find the wireless interface. It has wireless directories, for example in my case it’s wlp10 . You can check it using ls wlp10 . If the directory’s name different, use that directory’s name.
3. sudo iwlist wlp1s0 scan | grep ESSID

From here you can list all available Wi-Fi access points.

Further to what has been already answered here, I’ve merged a few of them and added a little flavor of my own.

As for the nmcli answer, sure, do that if you want to install more software. But if you’re looking for Access Points, maybe you don’t have an internet connection yet and are unable to connect to install said software. With all that said, here’s my solution:

for i in $(ls /sys/class/net/ | egrep -v ^lo$); do sudo iw dev $i scan | grep SSID | awk ''; done 2>/dev/null | sort -u 

for i in $(ls /sys/class/net/ | egrep -v ^lo$); 

Lets have a look at all the contents of the location /sys/class/net. This will list all the network devices, but we’re not really interested in the loopback interface. so we’ll ignore that one

do sudo iw dev $i scan | grep SSID | awk '';done 

For each of the network interfaces we found above, lets do the scan to list all the SSIDs (and only the SSIDs)

And ignore all the errors (like searching for SSIDs with ethernet interfaces).

And finally, If you have multiple wi-fi adapters on the system, only list each SSID once.

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