How can I add a Child in my xml file with fwrite - php

Question

I have a problem when I try to insert a new node to my xml file. I need to add:
<ul><loc> mylink</ul></loc>
before the last node in my xml file.
I tried the code below, but it doesn't work and it breaks the last node before I insert the new one:
$userfile = "sitemap.xml";
$fh = fopen($userfile, 'r+');
$addUser = "<url><loc>https://www.example.com/Privacy-Policy</loc></url></urlset> ";
fseek($fh, -10, SEEK_END);
fwrite($fh, $addUser);
fclose($fh);
This is part of my xml file:
<urlset >
<url>
<loc>example.com</loc>
</url>
<url>
<loc>example.com</loc>
</url>
</urlset>
my output is:
<urlset >
<url>
<loc>example1.com</loc>
</url>
<url>
<loc>example2.com</loc>
</ur<url> //<-- See here my xml file broke
<loc>example2.com</loc>
</url>
</urlset>

Answer 1

This should work for you:
(Here I just load the xml file with simplexml_load_file(), to create a SimpleXMLElement(). After this you can simply add a child to the root node)
<?php
$xml = simplexml_load_file("file.xml");
$xml = new SimpleXMLElement($xml->asXML());
$urlChild = $xml->addChild("url", "");
$urlChild->addChild("loc", "example2.com");
$xml->asXML("file.xml");
?>
input file:
<urlset >
<url>
<loc>example.com</loc>
</url>
<url>
<loc>example.com</loc>
</url>
</urlset>
output file:
<?xml version="1.0"?>
<urlset>
<url>
<loc>example.com</loc>
</url>
<url>
<loc>example.com</loc>
</url>
<url>
<loc>example2.com</loc>
</url>
</urlset>