如何让PHP回显XML标记?

I'm working on a site that has about 3,000-4,000 dynamically generated pages, and I'm looking to update the XML sitemap. I've tried using online generators in the past, and they never seem to capture all the pages correctly, so I was just going to do something myself. Basically I have something like:I'm working on a site that has about 3,000-4,00