Wish the web server handles route {/printed-programs/(\d+)\.folk$} with handler {
    regexp {/printed-programs/(\d+)\.folk$} $path -> id
    set filename "../folk-printed-programs/$id.folk" 
    set fp [open $filename r]
    set data [read $fp]
    close $fp

    dict create statusAndHeaders "HTTP/1.1 200 OK\nConnection: close\nContent-Type: text/plain; charset=utf-8\n\n" body $data
}