magnet.php

#!/usr/bin/env php
/**
 * @author Elouan Martinet <exa@elou.world>
 * @copyright Copyright (c) 2017, Elouan Martinet
 * @license AGPL-3.0+
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 * @version 0.0.4
 */
<?php
function startsWith($str, $start) {
    return substr($str, 0, strlen($start)) === $start;
}
function getArgs() {
    global $argc, $argv;
    if(isset($argc) && $argc > 1 && $argc <= 3) {
        $start = 'magnet:?xt=urn:btih:';
        if($argc === 2 && startsWith($argv[1], $start)) {
            $pos = strpos($argv[1], '&');
            $res = array(
                'hash' => substr($argv[1], strlen($start), $pos - strlen($start)),
                'dn' => null,
                'tr' => array(),
            );
            $args = explode('&', substr($argv[1], $pos + 1));
            foreach($args as $arg) {
                $k = substr($arg, 0, 2);
                $v = substr($arg, 3);
                if($k !== false && $v !== false) {
                    if($k === 'dn')
                        $res['dn'] = $v;
                    else if($k == 'tr')
                        $res['tr'][] = $v;
                }
            }
            return $res;
        } elseif($argc === 3)
            return array(
                'hash' => $argv[1],
                'dn' => urlencode($argv[2]),
                'tr' => array(),
            );
    }
    echo 'Usage: ' . "\n"
        . "\t" . $argv[0] . ' "magnet:?xt=urn:btih:<hash>&dn=<name>..."' . "\n"
        . "\t" . $argv[0] . ' <hash> "<name>"' . "\n";
    return false;
}
$args = getArgs();
if($args === false)
    exit(1);
$trackers = array(
    '', /* s/\//%2F/g s/:/%3A/g */
);
$added = array();
foreach($args['tr'] as $tr) {
    if(!in_array($tr, $trackers))
        $added[] = (strpos($tr, '/') === false) ? $tr : urlencode($tr);
}
$res = 'magnet:?xt=urn:btih:' . $args['hash'] . '&dn=' . $args['dn'];
foreach($added as $tr)
    $res .= '&tr=' . $tr;
foreach($trackers as $tr)
    $res .= '&tr=' . $tr;
echo 'Link:' . "\n"
    . $res . "\n";