html "$webenv(SERVER_PROTOCOL) 200 OK
Date: [clock format [clock seconds]]
Server: $webenv(SERVER_SOFTWARE)
Content-type: text/plain\n\n"
if {[catch {set fp [open $webenv(QUERY_STRING)] }] != 0} {
html "$webenv(QUERY_STRING) is not available for listing."
} else {
html [read $fp]
}