Creates button to export all posts in WP into a CSV

export-posts.php

add_action( 'restrict_manage_posts', 'add_export_button' );
function add_export_button() {
    $screen = get_current_screen();
 
    if (isset($screen->parent_file) && ('edit.php' == $screen->parent_file)) {
        ?>
        <input type="submit" name="export_all_posts" id="export_all_posts" class="button button-primary" value="Export All Posts">
        <script type="text/javascript">
            jQuery(function($) {
                $('#export_all_posts').insertAfter('#post-query-submit');
            });
        </script>
        <?php
    }
}

add_action( 'init', 'func_export_all_posts' );
function func_export_all_posts() {
    if(isset($_GET['export_all_posts'])) {
        $arg = array(
                'post_type' => 'post',
                'post_status' => 'publish',
                'posts_per_page' => -1,
            );
 
        global $post;
        $arr_post = get_posts($arg);
        if ($arr_post) {
 
            header('Content-type: text/csv');
            header('Content-Disposition: attachment; filename="wp.csv"');
            header('Pragma: no-cache');
            header('Expires: 0');
 
            $file = fopen('php://output', 'w');
 
            fputcsv($file, array('Post Title', 'URL'));
 
            foreach ($arr_post as $post) {
                setup_postdata($post);
                fputcsv($file, array(get_the_title(), get_the_permalink()));
            }
 
            exit();
        }
    }
}