diff --git a/rash.rkt b/rash.rkt
new file mode 100644
index 0000000..bee2fcf
--- /dev/null
+++ b/rash.rkt
@@ -0,0 +1,16 @@
+#lang racket/base
+
+(require readline/readline)
+(require racket/string)
+
+(define (do command . args)
+  (let ([cmd (find-executable-path command)])
+    (if cmd
+        (let-values ([(subproc in out err)
+                      (subprocess (current-output-port)
+                                  (current-input-port)
+                                  (current-error-port)
+                                  cmd
+                                  (string-join args " "))])
+          (subprocess-wait subproc))
+        (raise (exn:fail:filesystem command)))))