REBOL [ Title: "Etsy HTTP Hack" Date: 18-Sep-2012 Author: "Christopher Ross-Gill" ] use [fail-at][ fail-at: do bind [ remove-each [code response] response-actions [find [400 403 404 500] code] append response-actions [400 fail-at 403 fail-at 404 fail-at 500 fail-at] [ headers: make string! 500 while [ ( line: pick port/sub-port 1 ) <> "" ] [ append headers join line "^/" use [mk][ if parse/all line ["X-Error-Detail:" mk: to end][ append response-line back mk ] ] ] ; remove the headers system/words/close port/sub-port net-error response-line port/status: 'file ] ] last second get in system/schemes/http/handler 'open ]