code.delx.au - monosys/blob - wifi-scan

   1 #!/usr/bin/env node
   2 'use strict'
   3
   4 const {exec} = require('child_process');
   5
   6 function execAsync(command, opts) {
   7     return new Promise((resolve, reject) => {
   8         exec(command, opts, (error, stdout, stderr) => {
   9             if (error) {
  10                 reject(error);
  11             } else {
  12                 resolve({stdout, stderr});
  13             }
  14         });
  15     });
  16 }
  17
  18 function sleep(n) {
  19     return new Promise((resolve) => setTimeout(resolve, n));
  20 }
  21
  22 async function findInterface() {
  23     const {stdout} = await execAsync('iw dev');
  24     const lines = stdout.split('\n')
  25         .map((line) => line.trim())
  26         .filter((line) => line.startsWith('Interface '))
  27         .map((line) => line.split(' ')[1]);
  28     return lines[0];
  29 }
  30
  31 async function scanInterface(iface) {
  32     const {stdout} = await execAsync(`sudo iw dev ${iface} scan`);
  33
  34     const results = [];
  35     let partial = null;
  36
  37     for (let line of stdout.split('\n')) {
  38         if (line.startsWith('BSS ')) {
  39             finishPartial();
  40             partial = {};
  41             partial.bssid = line.match(/[a-z0-9:]+/)[0];
  42         }
  43
  44         line = line.trim()
  45         if (line.startsWith('SSID: ')) {
  46             partial.ssid = line.split(':')[1].trim();
  47         }
  48         if (line.startsWith('signal: ')) {
  49             partial.signal = line.split(':')[1].trim();
  50         }
  51         if (line.startsWith('DS Parameter set: channel')) {
  52             partial.channel = line.split(':')[1].trim();
  53         }
  54     }
  55
  56     function finishPartial() {
  57         if (!partial) {
  58             return;
  59         }
  60
  61         partial.ssid = partial.ssid || '';
  62         partial.channel = partial.channel || '';
  63
  64         const sortKey = [
  65             parseFloat(partial.signal),
  66             parseInt(partial.channel.split(' ')[1])
  67         ];
  68
  69         results.push([sortKey, partial]);
  70     }
  71
  72     return results
  73         .sort()
  74         .map(([, {bssid, ssid, signal, channel}]) => {
  75             ssid = ssid.padStart(40, ' ');
  76             channel = channel.padEnd(10, ' ');
  77             return `${signal}  ${channel}  ${ssid}  ${bssid}`;
  78         })
  79         .join('\n') + '\n';
  80 }
  81
  82 async function main() {
  83     const iface = await findInterface();
  84
  85     for (;;) {
  86         const scanResult = await scanInterface(iface).catch((err) => err.toString());
  87         process.stdout.write('\x1b[2J\x1b[0f');
  88         process.stdout.write(scanResult);
  89         await sleep(3000);
  90     }
  91 }
  92
  93 main().catch((err) => {
  94     console.log('Unhandled error!', err);
  95     process.exit(1);
  96 });