turn the ed wrapper into its own procedure

palps.rkt

@@ -8,35 +8,12 @@
     (or/c char-numeric? char-alphabetic? (curry char=? #\-))
     (string->list call))))
 
-;; get callsign, first thing passed by BPQ
-(define call (read-line (current-input-port) 'any))
-
-;; drop SSID
-(set! call (first (string-split call "-")))
-
-;; downcase callsign
-(set! call (string-downcase call))
-
-;; if the sysadmin has created a directory for that callsign, then
-;; they are an authorized user.
-(when (not (directory-exists? call))
-  (displayln "sorry, but you are not an authorized user of the PALPS system")
-  (displayln "visit https://gitea.farpn.net/w6vvn/palps for an explanation")
-  (flush-output)
-  (exit))
-
-;; change to the authroized users directory
-(current-directory call)
-
-(printf "welcome ~a. now starting (r)ed, the standard text editor~n" call)
-(flush-output)
-
 ;; unfortunately, we cannot just exec red and let it take over the
 ;; I/O. ed, being the standard text editor, only works with standard
 ;; line endings, \n. telnet and BPQ, however, use \r\n. \r\n upsets
 ;; ed, the standard text editor.  so we need to wrap the input and
 ;; output ports ourselves in order to provide this translation.
-
+(define (ed)
   (match-define
     (list stdout stdin pid stderr proc)
     (process* "/usr/bin/red"
@@ -73,10 +50,4 @@
          (close-input-port stdout)
          (close-input-port stderr)
          (proc 'kill)])))
-
-(loop)
-
-(displayln "goodbye")
-(flush-output)
-
-(exit)
+  (loop))