Node.jsでIPアドレスを取得

example.js

var ifconfig = require('./ifconfig');

ifconfig.inet4(function(result) {
  console.log(result);
});

ifconfig.js

var exec = require('child_process').exec;

var Ifconfig = function() {
  this.regexp = {};

  switch (process.platform) {
    case 'darwin':
      this.command = 'ifconfig';
      this.regexp.inet4 = /\binet\s+([^\s]+)/g;
      this.regexp.inet6 = /\binet6\s+([^\s]+)/g;
      break;
    default:
      this.command = 'ifconfig';
      this.regexp.inet4 = /\binet\b[^:]+:\s*([^\s]+)/g;
      this.regexp.inet6 = /\binet6\b[^:]+:\s*([^\s]+)/g;
      break;
  }
};

Ifconfig.prototype.inet4 = function(callback) {
  var self = this;

  exec(self.command, function(error, stdout, sterr) {
    var ips = [];
    var matches = stdout.match(self.regexp.inet4);

    for (var i = 0; i < matches.length; i++) {
      ips.push(matches[i].replace(self.regexp.inet4, "$1"));

      if (i == matches.length -1) {
        callback(ips);
      }
    }
  });
};

Ifconfig.prototype.inet6 = function(callback) {
  var self = this;

  exec(self.command, function(error, stdout, sterr) {
    var ips = [];
    var matches = stdout.match(self.regexp.inet6)
    
    for (var i = 0; i < matches.length; i++) {
      ips.push(matches[i].replace(self.regexp.inet6, "$1"));

      if (i == matches.length -1) {
        callback(ips);
      }
    }
  });
};

module.exports = new Ifconfig;