diff --git a/src/file-name-completion.scm b/src/file-name-completion.scm
new file mode 100644
index 0000000..2edcc33
--- /dev/null
+++ b/src/file-name-completion.scm
@@ -0,0 +1,25 @@
+
+(define *cache* #f)
+
+(define (executables-in-path)
+  (or *cache*
+      (begin 
+        (set! *cache* (executables-in-path-list (thread-fluid exec-path-list)))
+        *cache*)))
+
+(define (executables-in-path-list path-list)
+  (append-map! dir-executables path-list))
+
+(define (dir-executables dir)
+  (if (file-readable? dir)
+      (map file-name-nondirectory 
+           (filter executable? (glob (string-append dir "/*"))))
+      '()))
+
+(define (executable? name)
+  (with-errno-handler
+   ((errno packet)
+    (else #f))
+   (let ((info (file-info name)))
+     (and (file-info-executable? info)
+          (file-info-regular? info)))))
\ No newline at end of file
diff --git a/src/packages.scm b/src/packages.scm
index 864d37f..de8e27e 100644
--- a/src/packages.scm
+++ b/src/packages.scm
@@ -79,6 +79,13 @@
 	utils)
   (files button))
 
+(define-structure file-name-completion
+  (export executables-in-path)
+  (open scheme-with-scsh
+        srfi-1
+        thread-fluids)
+  (files file-name-completion))
+
 ;; *** key-grab ******************************************************
 
 (define-structure key-grab
@@ -215,7 +222,7 @@
 	utils key-grab
 	manager
 	move-wm split-wm switch-wm
-	prompt)
+	prompt file-name-completion)
   (files root-manager))
 
 (define-structure main
diff --git a/src/root-manager.scm b/src/root-manager.scm
index 13f4db6..42bf095 100644
--- a/src/root-manager.scm
+++ b/src/root-manager.scm
@@ -316,9 +316,10 @@
 	    (exec (prompt (root-wm:dpy root-wm) (wm:window cm)
 			  (get-option-value (root-wm:options root-wm)
 					    'execute-question)
-			  #f exec-complete)))
-       (if exec
-	   (run (sh -c ,(string-append exec " &"))))))
+			  #f (finite-complete (executables-in-path)))))
+       (and exec
+            (not (string=? exec ""))
+            (run (sh -c ,(string-append exec " &"))))))
     ((attach)
      (let* ((cm (root-wm:current-manager root-wm))
 	    (windows-above (window-path (wm:dpy cm) (wm:window cm)))
@@ -366,10 +367,6 @@
 	     (else (warn "unknown binding command" command))))
 	 (warn "unhandled root message" msg)))))
 
-(define (exec-complete str pos)
-  ;; TODO
-  (cons str pos))
-
 (define (finite-complete strings)
   (lambda (str pos)
     (let* ((s (substring str 0 pos))