MediaMash! fix HLS stream .m3u8 lists back to regular single file media

<?php

if(isset($_POST["m3u8"])&&strlen($_POST["m3u8"])){

  //https://cf-hls-media.sndcdn.com/playlist/jT6vVCgeToaf.128.mp3/playlist.m3u8

  $mpd=file_get_contents($_POST["m3u8"]);
  if(strlen($mpd)>40){
   $lns=explode("\n",$mpd);
   $udat="";
   foreach($lns as $ln){
      if(substr($ln,0,1)!="#"&&strlen($ln)>7)
      $udat.=",".$ln;
   }
   $udat=substr($udat,1);
  }else exit("error: ".$mpd);

}elseif(isset($_POST["comu"])&&strlen($_POST["comu"])){
  $udat=$_POST["comu"];
}

if(isset($udat)){
  $fns="".dechex(random_int(0 ,14400))."_".dechex(time());

  $frst=substr($udat,0,strpos($udat,","));

  if($qr=strpos($frst,"?")) $frst=substr($frst,0,$qr);

  if($ld=strrpos($frst,".")) $fns.=substr($frst,$ld);

  file_put_contents($fns.".csv",$udat);

  if($_["SERVER_PORT"]*1==443) $sL="s"; else $sL="";
  echo 'Result file: <a href="http'$sL.'://'.$_SERVER["HTTP_HOST"].'/'.$_SERVER["SCRIPT_NAME"].'/'.$fns.'"> '.$fns.'</a><br><a href="?">back to form</a>';
}elseif(isset($_SERVER["PATH_INFO"])&&strlen($_SERVER["PATH_INFO"])>7){
 $odat="";

 $urls=explode(",",file_get_contents(substr($_SERVER["PATH_INFO"],1).'.csv'));
 foreach($urls as $url){
   $odat.=file_get_contents($url);
 }

 $file_info = new finfo(FILEINFO_MIME);
 $mime_type = $file_info->buffer($odat);

 header("Content-Type: ".$mime_type);

 echo $odat;
}else

 echo '<html>
  <head>
    <title>MediaMash</title>
  </head>
  <body>
    MediaMash!<br><br>
    This proxy takes those irksome HLS .m3u8 playlists and mashes all those chunks together into one big media file.
    <br>
    It's very basic, it literally just appends their file data together, so don't be surprised if it doesn't work sometimes.
    <br>
    <br>
    <form method="POST" enctype="application/x-form-url-encoded">
    Input url to a HLS stream .m3u8 playlist:
    <input type="text" name="m3u8"><br>
    OR<br>
    Input comma separated individual media urls to mash together (must be same file type and bitrate):
    <br>
    <textarea name="comu" cols=250 rows=50 ></textarea>
    <br>
    <input type="submit" value="mash!">
    </form></body></html>';


?>