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diff --git a/rags.scm b/rags.scm
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--- /dev/null
+++ b/rags.scm
@@ -0,0 +1,187 @@
+(import (chicken io)
+        (chicken port)
+        (chicken file)
+        (chicken string)
+        (chicken pathname)
+        (chicken condition)
+        (chicken time posix)
+        (chicken process)
+        (chicken process-context)
+        matchable srfi-13
+        uri-common tcp6 openssl)
+
+(define-record config
+  root-dir host port certfile keyfile) 
+
+(define file-types
+  '(("gmi" "text/gemini" "charset=utf-8")
+    ("txt" "text/plain" "charset=utf-8")))
+
+(define (process-request config request-line)
+  (let ((uri (uri-normalize-path-segments (absolute-uri request-line))))
+    (cond
+     ((not (eq? (uri-scheme uri) 'gemini))
+      (fail-permanent "Unsupported scheme."))
+     ((not (uri-host uri))
+      (fail-permanent "URL lacks host name."))
+     ((not (equal? (uri-host uri) (config-host config)))
+      (fail-permanent "Proxy requests forbidden."))
+     ((uri-path-relative? uri)
+      (fail-permanent "Path must be absolute."))
+     ((not (document-available? config uri))
+      (fail-permanent "Document not found."))
+     (else 
+      (serve-document config uri)))))
+
+(define (fail-permanent reason)
+  (print "50 " reason "\r"))
+
+(define (document-available? config uri)
+  (file-exists? (document-path config uri)))
+
+(define (document-path config uri)
+  (let* ((crumbs (reverse (cons (config-root-dir config) (cdr (uri-path uri)))))
+         (path (make-pathname (reverse (cdr crumbs)) (car crumbs))))
+    (if (directory-exists? path)
+        (make-pathname path "index.gmi")
+        path)))
+    
+(define (serve-document config uri)
+  (let* ((path (document-path config uri))
+         (ext (pathname-extension path))
+         (mime-detected (assoc ext file-types))
+         (mime (if mime-detected mime-detected (assoc "txt" file-types)))
+         (mime-type (cadr mime)))
+    (print "20 " (string-intersperse (cdr mime) ";") "\r")
+    (cond 
+     ((and (equal? mime-type "text/gemini")
+           (file-executable? path))
+      (serve-text-dynamic path))
+     ((string-prefix? "text/" mime-type)
+      (serve-text-plain path))
+     (else (serve-binary path)))))
+
+(define (serve-text-plain path)
+  (with-input-from-file path
+    (lambda ()
+      (let loop ((str (read-string)))
+        (unless (eof-object? str)
+          (print* str)
+          (loop (read-string)))))))
+
+(define (serve-text-dynamic path)
+  (with-input-from-file path
+    (lambda ()
+      (let loop ((c (peek-char)))
+        (if (eof-object? c)
+            'done
+            (begin
+              (if (eq? c #\,)
+                  (begin
+                    (read-char)
+                    (serve-dynamic-element (read) (pathname-directory path))
+                    (read-line))
+                  (print (read-line)))
+              (loop (peek-char))))))))
+                              
+(define (serve-dynamic-element element working-directory)
+  (match element
+    (('eval expression)
+     (with-current-working-directory
+      working-directory
+      (lambda ()
+        (eval expression))))
+    (('shell command)
+     (with-current-working-directory
+      working-directory
+      (lambda ()
+        (let-values (((in-port out-port id) (process command)))
+          (let ((string (read-string #f in-port)))
+            (unless (eof-object? string)
+              (print string))
+            (close-input-port in-port)
+            (close-output-port out-port))))))
+    (else (error "Unknown element type."))))
+
+(define (with-current-working-directory directory thunk)
+  (let ((old-wd (current-directory))
+        (result 'none))
+    (condition-case
+        (begin
+          (change-directory directory)
+          (set! result (thunk))
+          (change-directory old-wd)
+          result)
+      (o (exn)
+         (change-directory old-wd)
+         (signal o)))))
+
+(define (run-server config)
+  (define listener (ssl-listen* hostname: (config-host config)
+                                port: (config-port config)
+                                certificate: (config-certfile config)
+                                private-key: (config-keyfile config)))
+
+  (print "Host: '" (config-host config) "'\n"
+         "Port: '" (config-port config) "'\n"
+         "Root directory: '" (config-root-dir config) "'\n"
+         "Cert file: '" (config-certfile config) "'\n"
+         "Key file: '" (config-keyfile config) "'\n"
+         "\n"
+         "Gemini server listening ...")
+
+  (server-loop listener config))
+
+(define (server-loop listener config)
+  (let-values (((in-port out-port) (ssl-accept listener)))
+    (let-values (((local-ip remote-ip) (tcp-addresses (ssl-port->tcp-port in-port))))
+      (print "Accepted connection from " remote-ip
+             " on " (seconds->string))
+      (condition-case
+          (let ((request-line (read-line in-port)))
+            (print* "Serving request '" request-line "' ... ")
+            (with-output-to-port out-port
+              (lambda ()
+                (process-request config request-line)))
+            (print "done."))
+        (o (exn)
+           (print-error-message o))))
+    (close-input-port in-port)
+    (close-output-port out-port))
+  (server-loop listener config))
+
+
+(define (print-usage progname)
+  (print "Usage: " progname " [-h] [-p port] server-root-dir hostname certfile keyfile"))
+
+(define (main)
+  (let* ((progname (pathname-file (car (argv))))
+         (config (make-config #f #f 1965 #f #f)))
+    (if (null? (cdr (argv)))
+        (print-usage progname)
+        (let loop ((args (cdr (argv))))
+          (let ((this-arg (car args))
+                (rest-args (cdr args)))
+            (if (string-prefix? "-" this-arg)
+                (cond
+                 ((or (equal? this-arg "-h")
+                      (equal? this-arg "--help"))
+                  (print-usage progname))
+                 ((or (equal? this-arg "-p")
+                      (equal? this-arg "--port"))
+                  (config-port-set! config (string->bumber (car rest-args)))
+                  (loop (cdr rest-args)))
+                 (else
+                  (print-usage progname)))
+                (match args
+                  ((root-dir host certfile keyfile)
+                   (config-root-dir-set! config root-dir)
+                   (config-host-set! config host)
+                   (config-certfile-set! config certfile)
+                   (config-keyfile-set! config keyfile)
+                   (run-server config))
+                  (else
+                   (print "One or more invalid arguments.")
+                   (print-usage progname)))))))))
+
+(main)