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 ${iface} scan`);
  34     return stdout;
  35 }
  36
  37 function formatScanResult(scanResult) {
  38     const results = [];
  39     let partial = null;
  40
  41     for (let line of scanResult.split('\n')) {
  42         if (line.startsWith('BSS ')) {
  43             finishPartial();
  44             partial = {};
  45             partial.bssid = line.match(/[a-z0-9:]+/)[0];
  46         }
  47
  48         line = line.trim()
  49         if (line.startsWith('SSID: ')) {
  50             partial.ssid = line.split(':')[1].trim();
  51         }
  52         if (line.startsWith('signal: ')) {
  53             partial.signal = line.split(':')[1].trim();
  54         }
  55         if (line.startsWith('DS Parameter set: channel')) {
  56             partial.channel = line.split(':')[1].trim();
  57         }
  58         if (line.startsWith('freq: ')) {
  59             partial.freq = 'freq ' + line.split(':')[1].trim();
  60         }
  61     }
  62
  63     function finishPartial() {
  64         if (!partial) {
  65             return;
  66         }
  67
  68         partial.ssid = partial.ssid || '';
  69         partial.channel = partial.channel || partial.freq || '';
  70
  71         const sortKey = [
  72             parseFloat(partial.signal),
  73             parseInt(partial.channel.split(' ')[1])
  74         ];
  75
  76         results.push([sortKey, partial]);
  77     }
  78
  79     return results
  80         .sort()
  81         .map(([, {bssid, ssid, signal, channel}]) => {
  82             ssid = ssid.padStart(40, ' ').substr(0, 40);
  83             channel = channel.padEnd(12, ' ');
  84             return `${signal}  ${channel}  ${ssid}  ${bssid}`;
  85         })
  86         .join('\n') + '\n';
  87 }
  88
  89 async function main() {
  90     const iface = process.argv[2] || await findInterface();
  91
  92     if (iface === '-') {
  93         const scanResult = await fs.readFile('/dev/stdin', 'utf-8');
  94         const prettyScanResult = formatScanResult(scanResult);
  95         process.stdout.write(prettyScanResult);
  96     } else {
  97         for (;;) {
  98             const scanResult = await scanInterface(iface).catch((err) => err.toString());
  99             const prettyScanResult = formatScanResult(scanResult);
 100             process.stdout.write('\x1b[2J\x1b[0f');
 101             process.stdout.write(prettyScanResult);
 102             await sleep(3000);
 103         }
 104     }
 105 }
 106
 107 main().catch((err) => {
 108     console.log('Unhandled error!', err);
 109     process.exit(1);
 110 });