MKV Default Audio Track Switcher

<?php
$dir = `ls -1 *.mkv`;
$files = split("\n",$dir);

foreach ($files as $file) {
    if (strlen($file) <= 0) {
        continue;
    }

    echo "Processing ".$file."...\n";
    $sample = `mkvinfo "$file"`;
    $tracks = preg_split("/\| \+ A track/",$sample);

    foreach ($tracks as $track) {
        $tag = "|  + Track number: ";
        $meh = strpos($track,$tag);
        if ($meh <= 0) {
            continue;
        }

        $meh = $meh + strlen($tag);
        $meh2 = strpos($track,"\n",$meh);
        $trackno = substr($track,$meh,($meh2 - $meh));

        $tag = "|  + Enabled: ";
        $meh = strpos($track,$tag);
        if ($meh <= 0) {
            continue;
        }
        $meh = $meh + strlen($tag);
        $meh2 = strpos($track,"\n",$meh);
        $enabled = substr($track,$meh,($meh2 - $meh));

        $tag = "|  + Default flag: ";
        $meh = strpos($track,$tag);
        if ($meh <= 0) {
            continue;
        }
        $meh = $meh + strlen($tag);
        $meh2 = strpos($track,"\n",$meh);
        $def = substr($track,$meh,($meh2 - $meh));

        $tag = "|  + Language: ";
        $meh = strpos($track,$tag);
        if ($meh <= 0) {
            continue;
        }
        $meh = $meh + strlen($tag);
        $meh2 = strpos($track,"\n",$meh);
        $lang = substr($track,$meh,($meh2 - $meh));

//      echo "Track Number: ".$trackno."\n";
//      echo "Enabled: ".$enabled."\n";
//      echo "Default: ".$def."\n";
//      echo "Language: ".$lang."\n";

        if ($enabled) {
            if ($lang == "eng" && !$def) {
                $cmd = 'mkvpropedit "'.$file.'" -e track:'.$trackno.' -s flag-default=1';
                exec($cmd);
                echo "Track ".$trackno." is ".$lang.". Set Default.\n";
            }
            if ($lang == "ger" && $def) {
                $cmd = 'mkvpropedit "'.$file.'" -e track:'.$trackno.' -s flag-default=0';
                exec($cmd);
                echo "Track ".$trackno." is ".$lang.". Set not default.\n";
            }
        }
    }
}