How to scan wifi networks on ubuntu (c++)?

Question

linux

Good afternoon!
Decided to learn c/c++ in my spare time. Hello World has already been written, and I want a more interesting task.
For example, now I want to sketch a program that will scan and display available wi-fi networks.
Tell me which way to look?
At the moment, I found the Wireless Tools library and an example of its use,
but I could not compile it:

main.cpp:12: undefined reference to `iw_sockets_open'

#include <iostream>
#include "libs/wireless_tools.29/iwlib.h"

int main() {
    std::cout << "Hello, World!" << std::endl;
    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, (char *) "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);

}

Please push me in the right direction :)

Answer 1

The example is working, you obviously forgot to specify this library to the linker. Your example works with a slight modification (the system #include <iwlib.h>one instead of yours, well, the interface name is different).
g++ -liw test.cc

Answer 2

does sort return something?