php download manager for vk.com music (for savefrom.net extension -> get all mp3 links)

up.php

<?php
$links = <<<EOL
https://psv4.vk.me/c536213/u23259354/audios/6622030b9956.mp3
https://psv4.vk.me/c6086/u3197020/audios/d0a867f54401.mp3
https://cs9-6v4.vk.me/p13/e2886ae987e8c5.mp3
https://psv4.vk.me/c6182/u211520772/audios/6ec1531bd181.mp3
https://psv4.vk.me/c536610/u886918/audios/0e3ad42b151d.mp3
https://psv4.vk.me/c6178/u47402845/audios/d45d27698600.mp3
https://cs9-6v4.vk.me/p13/17e4437ffe0922.mp3
https://psv4.vk.me/c6098/u2294877/audios/990035362c3a.mp3
EOL;

function ID3GetTags($file) 
{
    $f = fopen($file, 'rb');
    rewind($f); 

    fseek($f, -128, SEEK_END);
    $tmp = fread($f,128);

    $format = ($tmp[125] == Chr(0) and $tmp[126] != Chr(0)) 
        ? 'a3TAG/a30NAME/a30ARTISTS/a30ALBUM/a4YEAR/a28COMMENT/x1/C1TRACK/C1GENRENO'
        : 'a3TAG/a30NAME/a30ARTISTS/a30ALBUM/a4YEAR/a30COMMENT/C1GENRENO';

    $id3tag = unpack($format, $tmp);
    
    fclose($f);

    $result = array(
        'artist' => (isset($id3tag['ARTISTS']) && strlen($id3tag['ARTISTS']) > 0) ? $id3tag['ARTISTS'] : null,
        'title' => (isset($id3tag['NAME']) && strlen($id3tag['NAME']) > 0) ? $id3tag['NAME'] : null,
    );

    if ($result['artist'] == $result['title']) {
        $result['artist'] = $result['title'] = null;
    }

    return $result;
}

foreach (explode("\n", $links) as $link) {
    $link = trim($link);
    echo "\ndownload $link...\n";
    file_put_contents(md5($link) . ".mp3", file_get_contents($link));
    $tag = ID3GetTags(md5($link) . ".mp3");
    $artist = $tag['artist'] ? ucfirst($tag['artist']) . " - " : "";
    $title = $tag['title'] ? ucfirst($tag['title']) : md5($link);
    rename(md5($link) . ".mp3", trim($artist . $title) . ".mp3");
    echo "{$artist}{$title}.mp3 downloaded complete\n";
}