(PHP 5 >= 5.2.0)
DOMNode::C14NFile — Canonicalize nodes to a file
$uri
   [, bool $exclusive
   [, bool $with_comments
   [, array $xpath
   [, array $ns_prefixes
  ]]]] )Canonicalize nodes to a file.
uriPath to write the output to.
exclusiveEnable exclusive parsing of only the nodes matched by the provided xpath or namespace prefixes.
with_commentsRetain comments in output.
xpathAn array of xpaths to filter the nodes by.
ns_prefixesAn array of namespace prefixes to filter the nodes by.
   Number of bytes written or FALSE on failure