String Manipulation

getfield should get you where you want to go. You can use getfield to extract a specified field from a string. Using a slash as a delimiter and selecting field 2 you can get the first value after the slash in the URI.

This will get you the token without the slashes. You can check for the existence of a "." at that point but you won't be able to see if it ended with a slash. I'd suggest for that check you rescan the URI for the extracted token with a slash appended to it.

So, something like this should work:

Extract first element after slash in URI
set f [getfield [HTTP::uri] "/" 2]
 Check if field contains doesn't contain a dot
 and if the uri doesn't contain the field followed by a slash
if { not ($f contains ".") 
     and not ([HTTP::uri] contains "${f}/") } {
   Perform redirect.
  HTTP::redirect "http://[HTTP::host]/${f}/"
}

You could possibly use HTTP::uri in the redirect with a slash appended. That should produce the same result.

*Standard disclaimer: this iRule hasn't been tested...

-Joe