do and read-line in MrEd.

[Jordan Katz <katz@underlevel.net>]

Hi,

I have the following procedure which I use in MrEd: 

(define (grab-html b e)
  (define url (send urlbox get-value))
  (let-values ;;(((url) (send urlbox get-value))
   (((sin sout) (tcp-connect url 80))
    ((html-start) (regexp "Content-Type:.*")))
   (fprintf sout "GET http://www.~s HTTP/1.0~n~n" url)

   ;; read until "Content-Type..." is met
   (do ((line (read-line sin) (read-line sin)))
       ((not (regexp-match html-start line))))
   
   ;; `line' should now equal "Content-Type:..."
   ;; so I need to read past it
   (read-line sin)
   (read-line sin)  ;; once more for the blank line

   ;; print the actual source
   (do ((line (read-line sin) (read-line sin)))
       ((eof-object? line)) (printf "~s~n" line))))

It's supposed to grab the HTML found in `url.'  In order to do this, I
must read through all the headers that are sent back when doing "GET
<url> HTTP1/.0\n\n" and print out all the lines from the line
beginning with "Content-type:" until EOF.  Assuming I run this
procedure on the host underlevel.net, which has the following HTML
source (as seen by tcp-connect): 

  HTTP/1.1 200 OK
  Date: Mon, 02 Jul 2001 22:29:25 GMT
  Server: Apache/1.3.4 (Unix) FrontPage/4.0.4.3 PHP/3.0.14
  Last-Modified: Fri, 18 May 2001 22:02:12 GMT
  ETag: "12881c-3b-3b059be4"
  Accept-Ranges: bytes
  Content-Length: 59
  Connection: close
  Content-Type: text/html

  <pre>
  underlevel.net
  ==============

  Free the text.
  </pre>

The function prints:

  "
  "
  "
  "
  "
  "
  "
  "
  "
  "
  "<pre>"
  "underlevel.net"
  "=============="
  ""
  "Free the text."
  "</pre>"

I cannot figure out where the preceding empty lines come from, or how
to fix it.  Can someone please advise?

Thanks a lot,
-- 
Jordan Katz <katz@underlevel.net>  |  Mind the gap