SMF to bbPress attachments import script (GD Attachments) via Mike Russell https://bbpress.org/forums/topic/smf-import-to-bbpress/page/5/#post-159797

smf-bbpress-gd.php

<?php
//Standalone script to import smf attachments for the GD bbPress Attachments plugin
//Execute after you have imported smf into bbPress
require( 'wp-load.php' );
require( 'wp-admin/includes/image.php' );

$verbose = false;
//$limit = " LIMIT 0,1";
$limit = " LIMIT 0,99999";

// source database connection
$host="localhost";
$uname="xxx";
$pass="xxx";
$database = "xxx";
$site_url = 'http://xxx/forum';
$forum_path = 'forum/attachments/';

echo "start smf_attachments-to-bbpress\n"; flush();

//get the attachment rows from SMF
$smf_db = new wpdb($uname, $pass, $database, $host);
$smf_rows = $smf_db->get_results("
								SELECT * FROM <code>smf_attachments</code> 
								WHERE file_hash != '' 
									AND filename NOT LIKE '%thumb' 
								ORDER BY <code>id_attach</code>"
								.$limit);
								
echo "processing ".$smf_rows->num_rows." rows total\n";

// process each row
$count = 0;
foreach ($smf_rows as $smf_attachment_row) {
	if($verbose) { echo 'next row, id_attach = '.$smf_attachment_row->id_attach."\n"; flush(); }

	//look for both a new and old style filename.  If neither exists, skip this attachment
	$smf_filename = $forum_path.$smf_attachment_row->id_attach.'_'.$smf_attachment_row->file_hash;
	if(!file_exists($smf_filename))
		$smf_filename = $forum_path.$smf_attachment_row->id_attach.'_'.$smf_attachment_row->filename.$smf_attachment_row->file_hash;
	
	if(!file_exists($smf_filename))
	{
		echo "no file, skipping attachment for ".$smf_attachment_row->id_attach.", missing SMF file: ".$smf_filename."\n"; flush();
		continue;
	}
	
	$uploads = wp_upload_dir('SMF');
	$new_upload_dir = $uploads['path'];
	$new_full_filename = $new_upload_dir.'/'.$smf_attachment_row->filename;
	if($verbose) { echo('old->new = '.$smf_filename.' -> '.$new_full_filename."\n"); flush(); }
	
	//copy the enclosed file if necessary
	if(!file_exists($new_full_filename) && !copy($smf_filename, $new_full_filename) ) {
		echo "cannot copy: ".$smf_filename."->".$new_full_filename."\n";
	} else {
		//look for bbPress's previously imported topic or reply for the current attachment
		$parent_args = array(
			'post_type' => array('topic', 'reply'),
			'meta_key' => '_bbp_post_id',
			'meta_value' => $smf_attachment_row->id_msg
		);
		//echo "$parent_args = ".print_r($parent_args)."\n";
		
		$parent_query = new WP_Query($parent_args);
		$parent_query->get_posts();
		if($verbose) { echo $parent_query->post_count." posts found for smf_post id ".$smf_attachment_row->id_msg."\n"; flush(); }

		//normally only one post references a given enclosure, but handle possible multiples anyway ...
		while($parent_query->have_posts()) {
			$parent_query->the_post();
			$post_id = get_the_ID();
			$attachment_data = array(
				'guid' => $uploads['url'] . '/' . basename( $new_full_filename ),
				'post_mime_type'	=> 'image/'.$smf_attachment_row->fileext,
				'post_title'		=> $smf_attachment_row->filename,
				'post_status'		=> null,
				'post_content'		=> '',
			);
			//if($verbose) { echo "attachment_data = ".print_r($attachment_data)."\n"; flush(); }
			
			$attach_id = wp_insert_attachment($attachment_data, $new_full_filename, $post_id);

			//echo "attach_id = ".$attach_id."\n"; flush();
			if($attach_id) {
				//update_post_meta($attach_id, '_bbp_attachment', 1);
				if($attach_metadata = wp_generate_attachment_metadata($attach_id, $new_full_filename)) {
					//echo 'attach_metadata = '.print_r($attach_metadata)."\n"; flush();
					wp_update_attachment_metadata( $attach_id,  $attach_metadata );
					set_post_thumbnail( $post_id, $attach_id );				
				} else {
					echo 'wp_generate_attachment_metadata failed, fname = '.$new_full_filename."\n"; flush();
				}
			}
			wp_reset_postdata();
		}
	}
	$count++;
	if($count%100 == 0)
	{
		echo $count." attachments processed\r";
		flush();
	}
}
echo "Done, processed ".$count." records\n\n";

//clean up message body text
//convert <tt> -> <br />
mysql_query("UPDATE wp_posts SET post_content = REPLACE (post_content, \'<tt>\', \'<br />\') WHERE post_content LIKE \'%<tt>%\'");

mysql_close($connection);
exit;
?>