Example of querying wordpress posts, pages, and custom post types, then update the posts

query_wp.php

<?php
// this will probably take a while to run
//   so don't refresh the page, if the browser complains
//   continue to wait
// -1 posts per page will give ALL
//     will default to 10 if blank


// default blog posts
$blog_args = array(
	'post_type' => 'post',
	'posts_per_page' => -1
);
$blog_posts = get_posts($blog_args);


// default pages
$page_args = array(
	'post_type' => 'page',
	'posts_per_page' => -1
);
$page_posts = get_posts($page_args);


// custom post types
// example from thompson creek
$cpt_args = array(
	'post_type' => 'buying-guides',
	'posts_per_page' => -1
);
$cpt_posts = get_posts($cpt_args);


// get_posts() returns an array of post objects
// obj holds things like title, author, publish date, etc..
foreach($blog_posts as $p){
	// do the stripping here, lol
	// be sure that the obj has the updated content
	// ex: $p->post_content = $tripped_content;
	var_dump($p->post_content);

	// update the post
	wp_update_post($p);
}