locutus/php/network/inet_pton.js

Locutus other languages' standard libraries to JavaScript for fun and educational purposes

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.inet_pton = inet_pton;
function inet_pton(a) {
    //      discuss at: https://locutus.io/php/inet_pton/
    // parity verified: PHP 8.3
    //     original by: Theriault (https://github.com/Theriault)
    //     improved by: alromh87 and JamieSlome
    //       example 1: inet_pton('::')
    //       returns 1: '\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0'
    //       example 2: inet_pton('127.0.0.1')
    //       returns 2: '\x7F\x00\x00\x01'
    const f = String.fromCharCode;
    // IPv4
    const ipv4Match = a.match(/^(?:\d{1,3}(?:\.|$)){4}/);
    if (ipv4Match) {
        const octets = ipv4Match[0]
            .split('.')
            .slice(0, 4)
            .map((part) => Number.parseInt(part, 10));
        const [a0, a1, a2, a3] = octets;
        if (a0 === undefined ||
            a1 === undefined ||
            a2 === undefined ||
            a3 === undefined ||
            octets.some((octet) => Number.isNaN(octet) || octet < 0 || octet > 255)) {
            return false;
        }
        const packed = f(a0, a1, a2, a3);
        // Return if 4 bytes, otherwise false.
        return packed.length === 4 ? packed : false;
    }
    // IPv6
    if (a.length > 39) {
        return false;
    }
    const segments = a.split('::');
    if (segments.length > 2) {
        return false;
    } // :: can't be used more than once in IPv6.
    const reHexDigits = /^[\da-f]{1,4}$/i;
    const packedSegments = [];
    for (const segment of segments) {
        if (segment.length === 0) {
            packedSegments.push('');
            continue;
        }
        const hextets = segment.split(':');
        let packed = '';
        for (const hextetSource of hextets) {
            const hextet = hextetSource;
            // check if valid hex string up to 4 chars
            if (!reHexDigits.test(hextet)) {
                return false;
            }
            const parsedHextet = parseInt(hextet, 16);
            // Would be NaN if it was blank, return false.
            if (Number.isNaN(parsedHextet)) {
                // Invalid IP.
                return false;
            }
            packed += f(parsedHextet >> 8, parsedHextet & 0xff);
        }
        packedSegments.push(packed);
    }
    const bytesLength = packedSegments.reduce((total, part) => total + part.length, 0);
    if (bytesLength > 16) {
        return false;
    }
    if (segments.length === 1 && bytesLength !== 16) {
        return false;
    }
    return packedSegments.join('\x00'.repeat(16 - bytesLength));
}