created modules/general.rkt to house common functions

.gitignore

@@ -1,2 +1,10 @@
 # ignore temporary files
 *~ 
+
+# ignore logs and configuration files
+*.out
+*.conf
+
+# ignore racket compile files
+*.dep
+*.zo

Hermes/client.rkt

@@ -13,13 +13,13 @@
 (define host3 "localhost")
 (define port-num 4321)
 
-(define hermes-conf (open-output-file "./hermes.conf" 'append))
+(define hermes-conf (open-output-file "./hermes.conf" #:exists'append))
 (define hermes-conf-s (make-semaphore 1))
 
-(define convs-out (open-output-file "./convs.out" 'append))
+(define convs-out (open-output-file "./convs.out" #:exists 'append))
 (define convs-out-s (make-semaphore 1))
 
-(define error-out (open-output-file "./error.out" 'append))
+(define error-out (open-output-file "./error.out" #:exists 'append))
 (define error-out-s (make-semaphore 1))
 
 ; custodian for client connections

Hermes/modules/general.rkt

@@ -0,0 +1,24 @@
+#lang racket
+
+(provide displayln-safe)
+;; Several threads may want to print to stdout, so  lets make things civil
+; constant always available
+(define stdout (make-semaphore 1))
+
+; prints to stdout with an optional output port
+; requires a specified semaphore for the optional output port
+(define displayln-safe
+  (lambda (a-string [a-semaphore stdout] [a-output-port (current-output-port)])
+    (cond [(not (and (eq? a-semaphore stdout) (eq? a-output-port (current-output-port))))
+           (semaphore-wait a-semaphore)
+           (semaphore-wait stdout)
+           (displayln a-string a-output-port)
+           (flush-output a-output-port)
+           (displayln a-string)
+           (semaphore-post stdout)
+           (semaphore-post a-semaphore)]
+          [else
+            (semaphore-wait stdout)
+            (displayln a-string)
+            (semaphore-post stdout)])))
+

Hermes/server.rkt

@@ -1,6 +1,9 @@
 #lang racket
+
+(require "modules/general.rkt")
 (require math/base) ;; for random number generation
 
+
 ;; globals
 (define welcome-message "Welcome to Hermes coms. Type your message below")
 (define successful-connection-m "Successfully connected to a client. Sending client a welcome message.")
@@ -72,27 +75,6 @@
 ; semaphore to control access to c-messages
 (define messages-s (make-semaphore 1))  ;; control access to messages
 
-;; Several threads may want to print to stdout, so  lets make things civil
-; constant always available
-(define stdout (make-semaphore 1))
-
-; TODO refactor to take a port. defaults to current-output port in this context
-; Takes a string and a semaphore to print safely to stdout
-(define displayln-safe
-  (lambda (a-string [a-semaphore stdout] [a-output-port (current-output-port)])
-    (cond [(not (and (eq? a-semaphore stdout) (eq? a-output-port (current-output-port))))
-           (semaphore-wait a-semaphore)
-           (semaphore-wait stdout)
-           (displayln a-string a-output-port)
-           (flush-output a-output-port)
-           (displayln a-string)
-           (semaphore-post stdout)
-           (semaphore-post a-semaphore)]
-          [else
-            (semaphore-wait stdout)
-            (displayln a-string)
-            (semaphore-post stdout)])))
-
 ; two files to store error messages, and channel conversations
 (define error-out (open-output-file "/home/pcuser/Hermes/Hermes/error.txt" #:exists 'append))
 (define convs-out (open-output-file "/home/pcuser/Hermes/Hermes/conversations.txt" #:exists 'append))