Modify all posts

gistfile1.aw

<?php

/**
 * Fetching all posts from the database would suck up a lot of memory.
 * So instead this code processes 25 posts at a time.
 */

$posts_at_a_time = 25;

$query_args = array(
	'posts_per_page' => $posts_at_a_time,
	'offset' => 0,

	// Improve performance
	'update_post_term_cache' => false,
	'update_post_meta_cache' => false,
	'no_found_rows' => true,
);

$some_posts = new WP_Query( $query_args );

// Keep looping while posts were found
while ( $some_posts->post_count > 0 ) {

	// Loop through each found post
	while ( $some_posts->have_posts ) {
		$the_query->the_post(); // Set the $post global and some other stuff

		// Clone the post
		$modified_post = (array) $post;

		// Modify the post
		$modified_post['the_content'] .= "\n\n This new string is now on the end of the post.";

		// Save the modifcations
		wp_update_post( $modified_post );
	}

	// Get another chunk of posts to process
	$query_args['offset'] = $query_args['offset'] + $posts_at_a_time;
	$some_posts = new WP_Query( $query_args );
}