trailing slash

Give this a shot:

when HTTP_REQUEST {
  if { !([HTTP::uri] ends_with "/") } {
    HTTP::uri "[HTTP::uri]/"
  }
}

Now, keep in mind that this will append a slash to ALL URI's that don't end with a slash - including files with extensions/etc. If you want to mask them out then you might want to combine this with a matchclass or switch statement to mask out the uri's that you don't want to append a slash to.

-Joe