PHP | xml_parse() Function

<?php

// Create an XML parser
$parser = xml_parser_create();
 
// Set the character handler function
// for the XML parser
xml_set_character_data_handler($parser, "char_print");
 
// Opening xml file
$filePointer = fopen("gfg.xml", "r");
 
// Reading xml data from file
while ($data = fread($filePointer, 4096)) {
 
    // Parsing XML data
    xml_parse($parser, $data, feof($filePointer)) or
    
        // Display error when parse error occurs
        die (sprintf("XML Error: %s at line %d",
        
        // Error string
        xml_error_string(xml_get_error_code($parser)),
        
        // Current line        
        xml_get_current_line_number($parser)));
}
    
// Freeing xml parser
xml_parser_free($parser);
    
fclose($filePointer);
 
// Character handler function for XML parser
function char_print($parser, $data) {
    echo $data;
}
 
?>

<?php

// Create an xml parser
$xml_parser = xml_parser_create();

// Element handler function named "starting_handler"
// enables custom manipulation for output
function starting_handler($xml_parser, 
            $element_name, $element_attrs) {
    
    switch($element_name) {
        case "USER":
            echo "<u>USER DATA</u><br>";
            break;
        case "USERNAME":
            echo "Username: ";
            break;
        case "NAME":
            echo "Name: ";
            break;
        case "PHONE":
            echo "Phone no: ";
            break;
        case "DETAIL":
            echo "More about user: ";
    }
}

// Element handler function named "ending_handler"
function ending_handler($xml_parser, $element_name) {
    echo "<br>";
}

// Character handler function named "char_handler"
function char_handler($xml_parser, $xml_data) {
    echo $xml_data;
}

// Setting element handlers
xml_set_element_handler($xml_parser,
                "starting_handler", "ending_handler");

// Setting character data handler
xml_set_character_data_handler($xml_parser, "char_handler");

// Opening xml file
$file_pointer = fopen("gfg.xml", "r");

// Reading xml file 
while ($xml_data = fread($file_pointer, 4096)) {
 
    xml_parse($xml_parser, $xml_data, feof($file_pointer)) or
    
    // Display error while xml parsing    
    die (sprintf("XML Error: %s at line %d",
        
        // Error string
        xml_error_string(xml_get_error_code($xml_parser)),
    
        // Error line number
        xml_get_current_line_number($xml_parser)));
}

// Free xml parser
xml_parser_free($xml_parser);

// Closing file stream
fclose($file_pointer);

?>