implement command line

racket2nix.rkt

@@ -516,3 +516,19 @@
     (hash-set! acc pkg-name 'installed)
 
     (void)))
+
+(module+ main
+  (require racket/cmdline)
+  (define force? (make-parameter #f))
+  (define base-dir (make-parameter (build-path "racket-catalog")))
+  (command-line
+    #:program "racket2nix"
+    #:once-each
+    [("-f" "--force") "Overwrite existing nix files" (force? #t)]
+    [("-d" "--base-dir") bd "Base directory for nix files" (base-dir (bd))]
+    #:args (pkg . more-pkgs)
+
+    (define acc (make-hash))
+    (for ([pkg (in-list (cons pkg more-pkgs))])
+      (racket2nix pkg (force?) (base-dir) acc))))
+