getIP.js

module.exports.getIP = (function () {
    var ignoreRE = /^(127\.0\.0\.1|::1|fe80(:1)?::1(%.*)?)$/i;

    var exec = require('child_process').exec;
    var cached;
    var command;
    var filterRE;

    switch (process.platform) {
    case 'win32':
    //case 'win64': // TODO: test
        command = 'ipconfig';
        filterRE = /\bIP[^:\r\n]+:\s*([^\s]+)/g;
        // TODO: find IPv6 RegEx
        break;
    case 'darwin':
        command = 'ifconfig';
        filterRE = /\binet\s+([^\s]+)/g;
        // filterRE = /\binet6\s+([^\s]+)/g; // IPv6
        break;
    default:
        command = 'ifconfig';
        filterRE = /\binet\b[^:]+:\s*([^\s]+)/g;
        // filterRE = /\binet6[^:]+:\s*([^\s]+)/g; // IPv6
        break;
    }

    return function (callback, bypassCache) {
        if (cached && !bypassCache) {
            callback(null, cached);
            return;
        }
        // system call
        exec(command, function (error, stdout, sterr) {
            cached = [];
            var ip;
            var matches = stdout.match(filterRE) || [];
            //if (!error) {
            for (var i = 0; i < matches.length; i++) {
                ip = matches[i].replace(filterRE, '$1')
                if (!ignoreRE.test(ip)) {
                    cached.push(ip);
                }
            }
            //}
            callback(error, cached);
        });
    };
})();