Download a file from URL

Example:

$url = "http://domain.ext/filename.txt";
$result = system_retrieve_file($url, $destination = NULL, $managed = FALSE, $replace = FILE_EXISTS_REPLACE);

Return value

• If it succeeds and $managed is FALSE, the location where the file was saved.
• If it succeeds and $managed is TRUE, a \Drupal\file\FileInterface object which describes the file.
• If it fails, FALSE.