You should be able to do this:
get_user_name($bb_post->poster_id)
Tell me if that doesn’t work.
That does not work 
Here is the code I am using:
<?php foreach ( $recent as $bb_post ) : ?>
<li><a href="<?php post_link(); ?>"><?php topic_title($bb_post->topic_id); ?></a><small> <?php _e('Posted') ?> <?php echo date(__('F j, Y, h:i A'), bb_get_post_time()); ?><?php _e(' by ')?><?php get_user_name($bb_post->poster_id) ?></small>
seems like it should work. It doesn’t error out, it’s just blank after the ” by “
Is there a list of functions, similar to the WP codex, where I could learn about them?
Thanks.
bb_get_user($bb_post->poster_id) also did not work (does not error, just shows no output.)
also
$bb_post->poster_id does not return anything either.
Try this
echo bb_get_user($bb_post->poster_id)->user_login
Or you can try to do it the way topics do it and just use this:
post_author_link();
That will also return the name as a link to their webpage.
Worth a try I guess.
If neither of those work, you need to echo $bb_post->poster_id and see if you’re getting anything. If not, you gotta figure out wtf $bb_post contains.
OK – will try. Thank you for your help.
<?php _e(' by ')?><?php echo bb_get_user($bb_post->poster_id)->user_login ?>
Returns the user’s name. Perfect. Thanks.
Update: the above was working, but on the command line, php -l complained:
parse error, unexpected T_OBJECT_OPERATOR in … that line
I got this to work:
<?php _e(' by ') ?><a href="<?php user_profile_link($bb_post->poster_id); ?>"><?php echo get_user_name($bb_post->poster_id); ?></a>
That’s what was suggested initially: I’ m not sure what I did wrong the first time around, but this is what is working now, with no parse errors. Thanks.
I wonder if the problem with this line:
bb_get_user($bb_post->poster_id)->user_login
is related to this style syntax and could be fixed in a similar manner (if necessary):
https://bbpress.org/forums/topic/401?replies=42#post-2140