PHP: File Uploader

<?php
# @function upload_file
# 
# @param $field  string  the name of the file upload form field
# @param $dirPath string  the relative path to which to store the file (no trailing slash)
# @param $maxSize int   the maximum size of the file (in bytes)
# @param $allowed array  an array containing all the "allowed" file mime-types
#
# @return mixed  the files' stored path on success, false on failure.
function upload_file($field = '', $dirPath = '', $maxSize = 100000, $allowed = array())
{
 foreach ($_FILES[$field] as $key => $val)
  $$key = $val; 

 if ((!is_uploaded_file($tmp_name)) || ($error != 0) || ($size == 0) || ($size > $maxSize))
  return false; // file failed basic validation checks

 if ((is_array($allowed)) && (!empty($allowed)))
  if (!in_array($type, $allowed))  
   return false; // file is not an allowed type

 do $path = $dirPath . DIRECTORY_SEPARATOR . rand(1, 9999) . strtolower(basename($name));
 while (file_exists($path));

 if (move_uploaded_file($tmp_name, $path))
  return $path;

 return false;
}

// DEMO
/*
if (array_key_exists('submit', $_POST))
{
 if ($filepath = upload_file('music_upload', 'music_files', 700000, array('audio/mpeg','audio/wav')))
  echo 'File uploaded to ' . $filepath;
 else
  echo "An error occurred uploading the file... please try again.";
}
echo '   <form method="post" action="' .$_SERVER['PHP_SELF']. '" enctype="multipart/form-data">
   <input type="file" name="music_upload" id="music_upload" />
   <input type="submit" name="submit" value="submit" />
  </form>
 '; 
print_r($_FILES);  // for debug purposes
*/ 

?>

Refer to the commented section of code under the function labeled DEMO for usage.