small adjustments, many enhancements to rktplayer

utils.rkt

@@ -19,6 +19,7 @@
          warn-rktplayer
          fatal-rktplayer
          (all-from-out simple-log)
+         list-drop!
          )
 
 
@@ -50,6 +51,13 @@
     )
   )
 
+(define (list-drop! l idx)
+  (if (null? l)
+      l
+      (if (= idx 0)
+          (cdr l)
+          (cons (car l) (list-drop! (cdr l) (- idx 1))))))
+
 (define (make-delayed-reactor seconds closure)
   (let* ((last-val #f)
          (last-time -1)
@@ -87,11 +95,17 @@
   )
 
 (define (open-file-manager path)
-  (let ((folder (if (path? path) (path->string path) path)))
-  (case (system-type 'os)
-    [(windows) (process (string-append "explorer.exe " folder))]
-    [(macosx)  (process (string-append "open " folder))]
-    [else      (process (string-append "xdg-open " folder))]))
+  (let ((folder (if (path? path) (path->string path) path))
+        (do-open (λ (prg arg)
+                   (let ((exe (find-executable-path prg)))
+                     (dbg-rktplayer "(process* ~a ~a)" exe arg)
+                     (process* exe arg))))
+        )
+    (dbg-rktplayer "open-file-manager ~a" folder)
+    (case (system-type 'os)
+    [(windows) (do-open "explorer.exe" folder)]
+    [(macosx)  (do-open "open" folder)]
+    [else      (do-open "xdg-open" folder)]))
   )
 
 (define (basedir file)