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

   1 #!/usr/bin/env node
   2 'use strict'
   3
   4 const {exec} = require('child_process');
   5 const fs = require('fs').promises;
   6
   7 function execAsync(command, opts) {
   8     return new Promise((resolve, reject) => {
   9         exec(command, opts, (error, stdout, stderr) => {
  10             if (error) {
  11                 reject(error);
  12             } else {
  13                 resolve({stdout, stderr});
  14             }
  15         });
  16     });
  17 }
  18
  19 function sleep(n) {
  20     return new Promise((resolve) => setTimeout(resolve, n));
  21 }
  22
  23 async function findInterface() {
  24     const {stdout} = await execAsync('iw dev');
  25     const lines = stdout.split('\n')
  26         .map((line) => line.trim())
  27         .filter((line) => line.startsWith('Interface '))
  28         .map((line) => line.split(' ')[1]);
  29     return lines[0];
  30 }
  31
  32 async function scanInterface(iface) {
  33     const {stdout} = await execAsync(`sudo iw dev ${iface} scan`);
  34     return stdout;
  35 }
  36
  37 function formatScanResult(scanResult) {
  38     const results = [];
  39     let partial = null;
  40
  41     for (let line of scanResult.split('\n')) {
  42         if (line.startsWith('BSS ')) {
  43             finishPartial();
  44             partial = {};
  45             partial.bssid = line.match(/[a-z0-9:]+/)[0];
  46         }
  47
  48         line = line.trim()
  49         if (line.startsWith('SSID: ')) {
  50             partial.ssid = line.split(':')[1].trim();
  51         }
  52         if (line.startsWith('signal: ')) {
  53             partial.signal = line.split(':')[1].trim();
  54         }
  55         if (line.startsWith('DS Parameter set: channel')) {
  56             partial.channel = line.split(':')[1].trim();
  57         }
  58         if (line.startsWith('* primary channel:')) {
  59             partial.channel = 'channel ' + line.split(':')[1].trim();
  60         }
  61         if (line.startsWith('freq: ')) {
  62             partial.freq = 'freq ' + line.split(':')[1].trim();
  63         }
  64     }
  65
  66     finishPartial();
  67
  68     function finishPartial() {
  69         if (!partial) {
  70             return;
  71         }
  72
  73         partial.ssid = partial.ssid || '';
  74         partial.channel = partial.channel || partial.freq || '';
  75
  76         const sortKey = [
  77             parseFloat(partial.signal),
  78             parseInt(partial.channel.split(' ')[1])
  79         ];
  80
  81         results.push([sortKey, partial]);
  82     }
  83
  84     return results
  85         .sort()
  86         .map(([, {bssid, ssid, signal, channel}]) => {
  87             ssid = ssid.padStart(40, ' ').substr(0, 40);
  88             channel = channel.padEnd(12, ' ');
  89             return `${signal}  ${channel}  ${ssid}  ${bssid}`;
  90         })
  91         .join('\n') + '\n';
  92 }
  93
  94 async function main() {
  95     const iface = process.argv[2] || await findInterface();
  96
  97     if (iface === '-') {
  98         const scanResult = await fs.readFile('/dev/stdin', 'utf-8');
  99         const prettyScanResult = formatScanResult(scanResult);
 100         process.stdout.write(prettyScanResult);
 101     } else {
 102         for (;;) {
 103             const scanResult = await scanInterface(iface).catch((err) => err.toString());
 104             const prettyScanResult = formatScanResult(scanResult);
 105             process.stdout.write('\x1b[2J\x1b[0f');
 106             process.stdout.write(prettyScanResult);
 107             await sleep(3000);
 108         }
 109     }
 110 }
 111
 112 main().catch((err) => {
 113     console.log('Unhandled error!', err);
 114     process.exit(1);
 115 });