<?php
$file = "data.xml";
$depth = array();

function startelement($parser, $name, $attrs) {
   global $depth;
   for ($i = 0; $i < $depth[$parser]; $i++) {
       print "  ";
   }
   print "$name/n";
   $depth[$parser]++;
}

function endelement($parser, $name) {
   global $depth;
   $depth[$parser]--;
}

$xml_parser = xml_parser_create();
xml_set_element_handler($xml_parser, "startelement", "endelement");
if (!($fp = fopen($file, "r"))) {
   die("could not open xml input");
}

while ($data = fread($fp, 4096)) {
   if (!xml_parse($xml_parser, $data, feof($fp))) {
       die(sprintf("xml error: %s at line %d",
                   xml_error_string(xml_get_error_code($xml_parser)),
                   xml_get_current_line_number($xml_parser)));
   }
}
xml_parser_free($xml_parser);
?>