Regular Expression - HTTP URI

Here is an iRule that I shared with a few customers:

when HTTP_REQUEST {
        if { [HTTP::uri] starts_with "/abc"} {
                  set path [HTTP::uri]

                   variable loc marks the "Second" occurrence of a '/'.  This will drop /abc
                   if you want to drop /abc/xyz, locate the "Third" occurence of '/' by changing 1 to 2 at 

                  set loc [string first "/" $path 1]

                  set path_minus_root [string range $path $loc end]

                  Note:  the value of variable path_minus_root will start with a '/'
                  HTTP::redirect "https://www.company.com/new_site/qux$path_minus_root"
        }
}

You can also do this job using the [URI::path [HTTP::uri]] commands which are very useful.