xml
/*
    (c) 2000 hans anderson corporation.  all rights reserved.
    you are free to use and modify this class under the same
    guidelines found in the php license.
-----------
bugs/me:
    http://www.hansanderson.com/php/
    me@hansanderson.com
    showstv@163.com
-----------
version 1.0
- 1.0 is the first actual release of the class.  it's  
          finally what i was hoping it would be, though there
          are likely to still be some bugs in it.  this is
          a much changed version, and if you have downloaded
          a previous version, this won't work with your existing
          scripts!  you'll need to make some simple changes.
- .92 fixed bug that didn't include tag attributes
(to use attributes, add _attributes[array_index]
           to the end of the tag in question:
            $xml_html_head_body_img would become
            $xml_html_head_body_img_attributes[0],  
           for example)
-- thanks to nick winfield
              for reporting this bug.
- .91 no longer requires php4!
- .91 now all elements are array.  using objects has
          been discontinued.
*/
class xml_container{
function store($k,$v) {
        $this->{$k}[] = $v;
    }
}
/* parses the information */
/*********************************
*    类定义开始
*
*********************************/
class xml{
// initialize some variables
    var $current_tag=array();
    var $xml_parser;
    var $version = 1.0;
    var $tagtracker = array();
/* here are the xml functions needed by expat */
/* when expat hits an opening tag, it fires up this function */
    function startelement($parser, $name, $attrs){
array_push($this->current_tag, $name); // add tag to the cur. tag array
        $curtag = implode(_,$this->current_tag); // piece together tag
/* this tracks what array index we are on for this tag */
if(isset($this->tagtracker[$curtag])) {
            $this->tagtracker[$curtag]++;
        }
        else{
            $this->tagtracker[$curtag]=0;
        }
/* if there are attributes for this tag, we set them here. */
if(count($attrs)>0) {
            $j = $this->tagtracker[$curtag];
            if(!$j) $j = 0;
if(!is_object($globals[$this->identifier][$curtag][$j])) {
                $globals[$this->identifier][$curtag][$j] = new xml_container;
            }
$globals[$this->identifier][$curtag][$j]->store(attributes,$attrs);
        }
}// end function startelement
/* when expat hits a closing tag, it fires up this function */
    function endelement($parser, $name) {
        $curtag = implode(_,$this->current_tag); // piece together tag
// before we pop it off,
        // so we can get the correct
        // cdata
if(!$this->tagdata[$curtag]) {
            $popped = array_pop($this->current_tag); // or else we screw up where we are
            return; // if we have no data for the tag
        }
        else{
            $td = $this->tagdata[$curtag];
            unset($this->tagdata[$curtag]);
        }
$popped = array_pop($this->current_tag);
        // we want the tag name for
        // the tag above this, it  
        // allows us to group the
        // tags together in a more
        // intuitive way.
if(sizeof($this->current_tag) == 0) return; // if we aren't in a tag
$curtag = implode(_,$this->current_tag); // piece together tag
        // this time for the arrays
$j = $this->tagtracker[$curtag];
if(!$j) $j = 0;
if(!is_object($globals[$this->identifier][$curtag][$j])) {
            $globals[$this->identifier][$curtag][$j] = new xml_container;
        }
$globals[$this->identifier][$curtag][$j]->store($name,$td);
        #$this->tagdata[$curtag]);
        unset($td);
        return true;
    } // end function endelement
/* when expat finds some internal tag character data,
       it fires up this function */
function characterdata($parser, $cdata) {
        $curtag = implode(_,$this->current_tag); // piece together tag
        $this->tagdata[$curtag] .= $cdata;
    }
function xml($data,$identifier='xml') {
$this->identifier = $identifier;
// create parser object
        $this->xml_parser = xml_parser_create();
// set up some options and handlers
        xml_set_object($this->xml_parser,$this);
        xml_parser_set_option($this->xml_parser,xml_option_case_folding,0);
        xml_set_element_handler($this->xml_parser, startelement, endelement);
        xml_set_character_data_handler($this->xml_parser, characterdata);
if (!xml_parse($this->xml_parser, $data, true)) {
            sprintf(xml error: %s at line %d,
            xml_error_string(xml_get_error_code($this->xml_parser)),
            xml_get_current_line_number($this->xml_parser));
        }
// we are done with the parser, so let's free it
        xml_parser_free($this->xml_parser);
}//end constructor: function xml()
}//thus, we end our class xml
?>
操作方法：
require('class.xml.php');
$file = data.xml;
$data = implode(,file($file)) or die(could not open xml input file);
$obj = new xml($data,xml);
print $xml[hans][0]->num_results[0];
for($i=0;$i print $xml[hans][$i]->tag[0] . ;
}
to print url attributes (if they exist):
print $xml[hans][0]->attributes[0][size];