# Check wether an external alias is found and force a redirect if so

RewriteMap visible dbm:/usr/local/etc/httpd/conf/visible
RewriteCond ${visible:$1} .
RewriteRule ^/~([^/]+)/*(.*)$ ${visible:$1}$2 [R,L]

# First we have to append a slash to user directories where the trailing slash
# is missing. If we just say /* in the folling rule, sublinks won't work.

RewriteRule ^(/~[^/]+)$ $1/ [R,L]

# Now map internal aliases to user directories, if found - if not, just leave
# the request as is. We have to add PT to allow for mod_userdir

RewriteMap invisible dbm:/usr/local/etc/httpd/conf/invisible
RewriteCond ${invisible:$1} .
RewriteRule ^/~([^/]+)/(.*)$ ${invisible:$1}$2 [PT]