Connect to Magento 2 Composer repo and list packages you can access

pkglist.php

<?php


/**
 * Return the path of the auth.json file.
 */
function findAuthJson() {

    // Windows sets HOMEDRIVE and HOMEPATH, but cygwin sets HOME.
    if (!isset($_SERVER["HOME"]) && isset($_SERVER["HOMEDRIVE"])) {
        $home = $_SERVER["HOMEDRIVE"] . $_SERVER["HOMEPATH"];
    } else {
        $home = getenv("HOME");
    }

    $paths = [
        $home . '/.composer/auth.json',
        'auth.json',
        'app/etc/composer/auth.json'
    ];

    foreach ($paths as $path) {
        if (file_exists($path)) {
            return $path;
        }
    }

    echo "Unable to find 'auth.json' file holding composer repo keys\n";
    exit(1);
}


/**
 * Returns username and password from ~/.composer/auth.json.
 * Returned in assciation with keys "username" and "password".
 */
function getAuthUsernamePassword() {
    $authName = findAuthJson();
    $auth = json_decode(file_get_contents($authName), true);
    $up = $auth["http-basic"]["repo.magento.com"];
    return $up;
}


/**
 * Fetch packages.json file.
 */
function getPackagesJson() {

    $userpass = getAuthUsernamePassword();

    $process = curl_init();
    curl_setopt($process, CURLOPT_URL, 'https://repo.magento.com/packages.json');
    curl_setopt($process, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
    curl_setopt($process, CURLOPT_USERPWD, $userpass['username'] . ":" . $userpass['password']);
    curl_setopt($process, CURLOPT_TIMEOUT, 30);
    curl_setopt($process, CURLOPT_RETURNTRANSFER, TRUE);
    $return = curl_exec($process);
    curl_close($process);

    return json_decode($return, true);
}



$packagesJson = getPackagesJson();

foreach ($packagesJson['packages'] as $packageName => $versions) {
    $keep = false;
    foreach ($versions as $version => $package) {
        $description = $package['description'];
        $type = $package['type'];
        if ($type !== 'magento2-module'
        && $type !== 'magento2-library'
        && $type !== 'magento2-component'
        && $type !== 'library') {
            $keep = true;
        } else if (substr($packageName, 0, 8) !== "magento/") {
            $keep = true;
        }
    }

    if ($keep) {
        $versionNumbers = implode(' ', array_keys($versions));
        echo "$packageName [$type]\n";
        foreach ($versions as $version => $package) {
            $dep = '';
            if (isset($package['require'])) {
                foreach ($package['require'] as $dp => $dv) {
                    if ($dp !== 'php' && $dp !== 'composer/composer') {
                        $dep .= " $dp:$dv";
                    }
                }
            }
            $line = "    $version$dep";
            if (strlen($line) > 78) {
                $line = substr($line, 0, 75) . '...';
            }
            echo "$line\n";
        }
        $d = wordwrap($description, 72, "\n    ");
        echo "    $d\n\n";
    }
}