Fill a CDDB template from ripped files

#!/usr/bin/env php
<?php
$template = file_get_contents('php://stdin');
$dir      = $argv[1];
 
$files = glob($dir . '/*.ogg');
$category = null;
$genreCategoryMap = [
    'Pop' => 'rock',
    'Rock' => 'rock',
];
foreach ($files as $file) {
    $info = shell_exec(
        'vorbiscomment'
        . ' ' . escapeshellarg($file)
    );
    $lines = explode("\n", $info);
 
    $data = [];
    foreach ($lines as $line) {
        $line = trim($line);
        if ($line === '') {
            continue;
        }
        $parts = explode('=', $line, 2);
        if (count($parts) == 2) {
            $data[$parts[0]] = $parts[1];
        }
    }
 
    if (!isset($data['album'])
        || !isset($data['artist'])
        || !isset($data['title'])
        || !isset($data['genre'])
        || !isset($data['date'])
        || !isset($data['tracknumber'])
    ) {
        echo "Meta data missing in $file:\n";
        var_dump($data);
        exit();
    }
 
    $template = preg_replace(
        "#DTITLE=.+\n#",
        'DTITLE='
        . $data['artist'] . ' / ' . $data['album']
        . "\n",
        $template
    );
 
    $template = preg_replace(
        "#DYEAR=\n#",
        'DYEAR=' . $data['date'] . "\n",
        $template
    );
 
    $template = preg_replace(
        "#DGENRE=\n#",
        'DGENRE=' . $data['genre'] . "\n",
        $template
    );
 
    if (isset($genreCategoryMap[$data['genre']])) {
        $template = preg_replace(
            "|#CATEGORY=.+\n|",
            'CATEGORY=' . $genreCategoryMap[$data['genre']] . "\n",
            $template
        );        
    }
 
    $track = intval($data['tracknumber']) - 1;
    $template = preg_replace(
        "#TTITLE" . $track . "=.+\n#",
        'TTITLE' . $track . '=' . $data['title'] . "\n",
        $template
    );
 
    //var_dump($info, $data);
    //die();
}
 
echo $template;
?>